Injection Of Estradiol Benzoate Research Articles

The role of Ca2+ signalling and InsP3R in the pathogenesis of intrahepatic cholestasis of pregnancy

Background In order to contribute new insights for future prevention and treatment of intrahepatic cholestasis of pregnancy (ICP), and to promote positive pregnancy outcomes, we evaluated serum Ca2+ levels and inositol 1,4,5-trisphosphate receptor (InsP3R) expression in the liver tissue of a rat ICP model. Methods After establishing the model by injection of oestradiol benzoate and progesterone into pregnant rats, animals were divided into normal control (n = 5) and ICP model groups (n = 5). The expression of InsP3R protein in the liver, and serum levels of Ca2+, glycocholic acid and bile acid were detected. Results InsP3R mRNA and protein were significantly lower in the ICP model group compared to the normal group, as determined by qPCR and immunohistochemistry, respectively. Serum enzyme-linked immunosorbent assay results revealed significantly higher levels of glycocholic acid and bile acid in the ICP model group compared to the normal group, while Ca2+ levels were significantly lower. The levers of Ca2+ were significantly and negatively correlated with the levels of glycocholic acid. The observed decrease in Ca2+ was associated with an increase in total bile acids, but there was no significant correlation. Conclusions Our results revealed that the expression of InsP3R and serum Ca2+ levels was significantly decreased in the liver tissue of ICP model rats. Additionally, Ca2+ levels were found to be negatively correlated with the level of glycocholic acid.

Estrogen-mediated individual differences in female rat voluntary running behavior.

Regular exercise has numerous health benefits, but the human population displays significant variability in exercise participation. Rodent models, such as voluntary wheel running (VWR) in rats, can provide insight into the underlying mechanisms of exercise behavior and its regulation. In this study, we focused on the role of estrogen on VWR in female rats. Female rats run more than males, and we aimed to determine to what extent running levels in females were regulated by estrogen signaling. The running behavior of rats (duration, speed, and total distance run) was measured under normal physiological conditions, ovariectomy (OVX), and estrogen replacement in an OVX background. Results show cyclic variations in running linked to the estrous cycle. Ovariectomy markedly reduced running and eliminated the cyclic pattern. Estrogen replacement through estradiol benzoate (EB) injections and osmotic minipumps reinstated running activity to pre-OVX levels and restored the cyclic pattern. Importantly, individual differences and ranking are preserved such that high versus low runners before OVX remain high and low runners after treatment. Further analysis revealed that individual variation in running distance was primarily caused by rats running different speeds, but rats also varied in running duration. However, it is noteworthy that this model also displays features distinct from estrogen-driven running behavior under physiological conditions, notably a delayed onset and a broader duration of running activity. Collectively, this estrogen causality VWR model presents a unique opportunity to investigate sex-specific mechanisms that control voluntary physical activity.NEW & NOTEWORTHY This study investigates estrogen's role in voluntary wheel running (VWR) behavior in female rats. Female rats exhibit greater running than males, with estrogen signaling regulating this activity. The estrous cycle influences running, whereas ovariectomy reduces it, and estrogen replacement restores it, maintaining individual differences under all conditions. Both running speed and duration contribute to VWR variations. These findings emphasize individual estrogen regulation in female exercise and provide an estrogen replacement animal model for investigating neurobiological underpinnings that drive voluntary exercise behavior.

Acupoint application therapy alleviates pain by regulating immune function through inhibiting TLR4/MyD88/NF-κB p65 signaling in a primary dysmenorrhea rat model.

To investigate the effects of graphene-based warm uterus acupoint paste on uterine Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear transcription factor-kappa B p65 (NF-κB p65) signaling pathway and Th1/Th2 immune balance in primary dysmenorrhea ( PD ) model rats, so as to reveal its immunological mechanisms of relieving dysmenorrhea. Thirty SD female rats were randomly divided into 3 groups：normal group, model group and acupoint paste group, with 10 rats in each group. PD rat model was established by subcutaneous injection of estradiol benzoate for 10 consecutive days. At the same time of modeling, graphene-based warm uterus acupoint paste was applied to the acupoints of "Guanyuan" (CV4), bilateral "Zigong" (EX-CA1) and "Sanyinjiao" (SP6) of rats in the acupoint paste group. The application was continuously applied once daily for 10 d, 5 h each time. On the 11th day, oxytocin was injected intraperitoneally to observe the writhing latency, writhing times within 30 min and writhing score of rats in each group. The spleen and thymus indexes were calculated. The pathological changes of spleen and thymus tissue were observed after HE staining. The contents of serum immunoglobulin (Ig) A, IgG, tumor necrosis factor-α (TNF-α), interleukin (IL)-2, interferon-γ (IFN-γ), IL-4 and IL-10 were detected by ELISA . The protein and mRNA expression levels of TLR4, MyD88 and NF-κB p65 in rat uterine tissue were detected by Western blot and real-time quantitative PCR, respectively. Compared with the normal group, the writhing times and writhing scores within 30 min of rats in the model group were significantly increased(P<0.001), and the rats showed writhing reaction (P<0.01). The spleen index and thymus index were significantly decreased(P<0.01, P<0.05). The spleen and thymus had obvious pathological changes. The contents of IgA, IgG, TNF-α, IL-2 and IFN-γ in serum were significantly increased, while the contents of serum IL-4 and IL-10 were significantly decreased(P<0.001, P<0.01). The expression levels of TLR4, MyD88, NF-κB p65 protein and corresponding mRNA in uterine tissue were significantly increased(P<0.001). Following intervention, compared with the model group, the writhing latency time of rats in the acupoint paste group was prolonged, and the writhing times and writhing scores within 30 min were significantly decreased (P<0.001). The spleen index and thymus index were significantly increased(P<0.01, P<0.05). The pathological changes of spleen and thymus were improved. The contents of serum IgA, IgG, TNF-α, IL-2 and IFN-γ were significantly decreased, while the contents of IL-4 and IL-10 were significantly increased(P<0.001, P<0.05, P<0.01). The expression of TLR4, MyD88, NF-κB p65 protein and the corresponding mRNA levels in uterine tissue were decreased(P<0.001, P<0.01). Graphene-based warm uterus acupoint paste can regulate the immune balance of Th1/ Th2 by regulating TLR4/ MyD88/ NF-κB p65 signaling pathway, repair the pathological damage of immune tissue, improve immune function, and effectively relieve the pain symptoms of PD rats.

Therapeutic effect of Leonuri Herba aqueous decoction on primary dysmenorrhea in rats and its metabolomic analysis

This study aimed to investigate the therapeutic effect of Leonuri Herba aqueous decoction on primary dysmenorrhea(PD) and explore the underlying mechanism in conjunction with untargeted metabolomics. Forty adult female rats were randomly divi-ded into a normal group, a model control group, ibuprofen(0.12 g·kg~(-1)) group, and high-and low-dose Leonuri Herba aqueous decoction(5 and 2.5 g·kg~(-1)) groups, with eight rats in each group. The PD rat model was prepared using intramuscular injection of estradiol benzoate combined with intraperitoneal injection of pitocin. Drugs were administered by gavage from the 4th day of modeling for 7 d. After the last administration, pitocin was injected intraperitoneally, and the writhing latency and writhing times within 30 min were recorded. The uterine and ovarian coefficients were determined. Estradiol(E_2), progesterone(Prog), oxytocin(OT), cyclooxyge-nase 2(COX-2), prostaglandin E_2(PGE_2), prostaglandin F_(2α)(PGF_(2α)), and Ca~(2+) levels in uterine tissues were measured by ELISA and biochemical kits. Morphological changes in uterine and ovarian tissues were observed by hematoxylin-eosin(HE) staining. The protein expression of oxytocin receptor(OTR), prostaglandin E_2 receptor 3(EP3), and estrogen receptor alpha(ERα) in uterine tissues was detected by immunohistochemistry. The mRNA expression of OTR, PGE_2 receptors 1-4(EP1, EP2, EP3, and EP4), and PGF_(2α) receptor(FP) in uterine tissues was detected by quantitative real-time PCR. Untargeted metabolomics analysis was performed by ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry(LC-QTOF-MS) technology to screen potential biomarkers and enrich metabolic pathways. The results showed that Leonuri Herba was able to significantly reduce the writhing times in PD rats(P&lt;0.05 or P&lt;0.01), significantly reduce the uterine and ovarian coefficients(P&lt;0.01), and improve their histomorphology. After treatment with Leonuri Herba, PGE_2 content was significantly increased(P&lt;0.05), COX-2, PGF_(2α) and Ca~(2+) content, and PGF_(2α)/PGE_2 was significantly decreased(P&lt;0.05 or P&lt;0.01), and OT content was decreased, while E_2 and Prog content tended to further increase in uterine tissues of PD rats. Correspondingly, OTR and EP3 protein expression was significantly downregulated(P&lt;0.05 or P&lt;0.01) and ERα protein expression was upregulated(P&lt;0.05) in uterine tissues. The mRNA expression of FP and EP4 in uterine tissues was significantly downregulated(P&lt;0.01), and the mRNA expression of EP1, EP3, and OTR showed a decreasing trend. The untargeted metabolomics results showed that 10 differential metabolites were restored in the plasma of PD rats after Leonuri Herba treatment. The results indicate that Leonuri Herba is effective in the prevention and treatment of PD, and the underlying mechanism may be attributed to the regulation of PGs synthesis and corresponding receptor binding.

Administration of Estradiol Benzoate Enhances Ovarian and Uterine Hemodynamics in Postpartum Dairy Buffaloes.

The postpartum (PP) period is a crucial stage for the resumption of reproductive performance and ovarian cyclicity in dairy buffaloes. The present study aimed, for the first time, to assess the effect of the administration of estradiol benzoate (EB) on ovarian and uterine hemodynamics in PP dairy buffaloes. Eight pluriparous acyclic domestic buffaloes were enrolled in the present experiment and received a dose of 10 mg of estradiol benzoate (EB) intramuscularly 4 weeks after parturition. All animals were examined two times before EB administration (days -3, and -1) and on the day of EB administration (day 0), followed by examinations on days 1, 3, 5, 7, and 9 post-EB administration. The middle uterine artery (MUA) and ovarian artery (OA) blood flow patterns were assessed using a color Doppler ultrasound device. The reproductive parameters were (1) the cross-sectional diameters (cm) of the OA and MUA, (2) cranial uterine horn thickness (UHT; cm), and (3) hemodynamic changes within the MUA on both the ipsi- and contra-lateral sides of the previous pregnant horn and within the OA corresponding to the ovarian tissues. The examined blood flow parameters were the pulsatility index (PI), resistance index (RI), peak systolic/end-diastolic ratio (S/D), time-averaged maximum velocity (TAV; cm/s), uterine blood flow rate (BFR; bpm), and uterine blood flow volume (BFV; mL/min). Concomitantly, blood samples were collected from the coccygeal vein, and the sera were stored at -18 °C for use in estradiol (E2-17β) and nitric oxide (NO) assays. The results revealed increases in both OA and MUA cross-sectional diameter (cm) on the ipsi-lateral and contra-lateral (p < 0.05) sides within 24 h until day 9 post-treatment. The values of the RI and PI of blood flow within the OA and MUA on the ipsi-lateral and contra-lateral sides of the previous pregnancy were obviously lower (p < 0.05) at 24 h after the administration of EB, and then, started to gradually elevate, reaching the pre-treatment values on day 9 after EB administration. Both the BFR and BFV in the OA and MUA significantly increased from 24 h to 72 h after EB administration on both the ipsi-lateral and contra-lateral sides (p < 0.05); then, their values started to decrease to reach the pretreatment value on day 9 after EB administration. Both E2 and NO concentrations significantly increased (p < 0.05) from 24 h until day 3 after EB injection and then started to decline after that, reaching the pre-treatment value on day 9. In conclusion, the administration of EB enhances the ovarian and uterine blood flow concomitantly with increased levels of NO in PP dairy buffaloes.

Chloroform Fraction of Drymaria cordata Linn (CFDC) Suppresses Estradiol Benzoate- Induced Endometrial Hyperplasia

The diagnosis of uterine dysfunction (endometrial hyperplasia) is on the rise. The available treatment is quite expensive and associated with some side effects. The therapeutic potential of natural products is now being explored, as they are easily available with little or no side effects. Drymaraia cordata is folklorically utilized in the treatment of diverse ailments including uterine fibroids. This study aims to investigate the potential therapeutic effect of chloroform fraction of methanol extract of Drymaria cordata (CFDC) in estradiol benzoate (EB)-induced endometrial hyperplasia. Thirty-six rats were randomly divided equally into six groups. These included control group, CFDC: (100 mg/kg), CFDC: (200 mg/kg), EB: (2 mg/kg), EB + CFDC (100 mg/kg), and EB + CFDC (200 mg/kg). Endometrial hyperplasia (EH) was induced by intraperitoneal injection of EB. The levels of estrogen (E2), progesterone (PG), Follicle stimulating hormone (FSH), Luteinizing hormone (LH), Malondialdehyde (MDA), Superoxide dismutase (SOD), and Glutathione peroxidase (GSH-Px) activities were determined using ELISA technique. The uterine histological assessment and immunohistochemical expression levels of estrogen receptor, Ki-67, cytochrome c, and caspase 3 were carried out. EH was severely expressed in the uterine section of EB-treated rats. However, CFDC administration improved the pathological features of the animal model. The sex hormones levels were increased in the EB-treated group, which were significantly reduced by CFDC. The antioxidant indices were also restored by CFDC. Immunoexpression levels of ERα and Ki-67 were downregulated while cytochrome c and caspase 3 were upregulated by CFDC. This study suggests that CFDC contains phytochemicals that can protect against EB-induced EH via modulation of hormonal signaling, apoptotic machinery, and oxidative indices.

Effects of electroacupuncture on N-methyl-D-aspartate receptor and mitogen activated protein kinase in spinal cord of rats with primary dysmenorrhea

To observe the effects of electroacupuncture (EA) on the expression levels of N-methyl-D-aspartate receptor (NMDAR), extracellular signal-regulated kinase (ERK)1/2, p38 mitogen activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) in the spinal cord of rats with primary dysmenoramia (PDM), so as to explore the underlying mechanism of EA treating PDM. Thirty female SD rats were randomly divided into normal group, model group and EA group, with 10 rats in each group. The PDM rat model was established by subcutaneous injection of estradiol benzoate and oxytocin into the thigh. At the same time of modeling, rats in the EA group were treated with EA (50 Hz) at "Sanyinjiao" (SP36) and "Guanyuan" (CV4) once daily, 20 min each time, for 10 consecutive days. The writhing times, writhing score and writhing latency were observed within 30 min after oxytocin injection. The uterine pathological morphology was observed by HE staining, and pathological score was calculated. Serum prostaglandin F2α (PGF2α) and prostaglandin E2 (PGE2) were determined by ELISA. The protein expression levels of NMDAR, ERK1/2, p38MAPK and JNK in spinal cord were detected by Western blot. Compared with the normal group, the writhing times and writhing score were significantly increased (P<0.05); the endometrial epithelial cells showed vacuolar degeneration, death and hyperemia, the uterine pathological score was increased (P<0.05); the content of serum PGF2α and the ratio of PGF2α/PGE2 were significantly increased (P<0.01), while the content of serum PGE2 was significantly decreased (P<0.01); the expression levels of NMDAR, ERK1/2, p38MAPK and JNK in spinal cord were significantly increased (P<0.05, P<0.01) in the model group. Compared with the model group, the writhing times and writhing score were significantly decreased (P<0.05), the writhing latency was prolonged (P<0.05); the endometrial epithelial cells still showed vacuolar degeneration, death and hyperemia, and the uterine pathological score was decreased (P<0.01); the content of serum PGF2α and the ratio of PGF2α/PGE2 were significantly decreased (P<0.01), while the content of serum PGE2 was significantly increased (P<0.01); the protein expression levels of ERK1/2 and JNK in spinal cord were significantly decreased (P<0.01) in the EA group. EA intervention at SP36 and GV4 has obvious analgesic effect on PDM rats, and its mechanisms may be related to reducing serum prostaglandin, alleviating uterine inflammation, and inhibiting the protein expressions of NMDAR, ERK1/2, p38 MAPK and JNK in spinal cord.

Effects of electroacupuncture on NLRP3 inflammasome and pyroptosis protein GSDMD in uterine tissue in rats with primary dysmenorrhea

To observe the effects of electroacupuncture (EA) on NLRP3 inflammasome and its downstream protein gastermin D (GSDMD) in rats with primary dysmenorrhea (PDM), and to explore the potential mechanism of EA on the treatment of PDM. Forty healthy female SD rats without pregnancy were randomly divided into a control group, a model group, an EA group and an ibuprofen group, 10 rats in each group. PDM model was prepared by injection of estradiol benzoate and oxytocin. Except the control group, the rats in each group were subcutaneously injected with estradiol benzoate for 10 days, and oxytocin was injected on the 11th day. The rats in the EA group were intervened with EA (dense wave, frequency of 50 Hz) at "Guanyuan" (CV 4) and "Sanyinjiao" (SP 6) at the same time of modeling, once a day, 20 min each time, for 10 consecutive days. The rats in the ibuprofen group were treated with 0.8 mL of ibuprofen by gavage (concentration of ibuprofen solution was 1.25 mg/mL) for 10 consecutive days. After modeling, the writhing reaction was observed. After intervention, the HE staining method was used to observe the histological morphology of uterus and evaluate the pathological damage score of uterus; ELISA method was used to detect the serum levels of prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α); Western blot method was used to detect the protein expression of NLRP3, apoptosis related spot like protein (ASC), caspase-1, GSDMD, GSDMD-N and inflammatory factors (interleukin [IL]-1β, IL-18) in uterine tissue. In the model group, a large number of vacuolar degeneration and death of endometrial epithelial cells, spiral arterioles congestion in lamina propria and neutrophil infiltration were observed. In the EA group, there was a small amount of vacuolar degeneration and death of endometrial epithelial cells, a small amount of spiral arterioles congestion in the lamina propria, and a small amount of neutrophils infiltration. In the ibuprofen group, there was very small number of degeneration and death of endometrial epithelial cells, and no obvious arterial congestion was found in lamina propria, and neutrophil infiltration was occasionally seen. Compared with the control group, in the model group the number of writhing was increased (P<0.01), the writhing reaction score and serum level of PGF2α and PGF2α/PGE2 value were increased (P<0.01), the level of PGE2 was decreased (P<0.01). Compared with the model group, in the EA group and the ibuprofen group the number of writhing were decreased (P<0.05), the latency of writhing was prolonged (P<0.01), the writhing reaction scores and serum levels of PGF2α and PGF2α/PGE2 values were decreased (P<0.05, P<0.01), the levels of PGE2 were increased (P<0.01). Compared with the control group, the protein expression of NLRP3, ASC, caspase-1, GSDMD, GSDMD-N, IL-1β and IL-18 in the uterine tissues of rats was increased in the model group (P<0.01). Compared with the model group, the protein expression of NLRP3, ASC, caspase-1, GSDMD, GSDMD-N, IL-1β and IL-18 in the uterine tissues of rats was decreased in the EA group and the ibuprofen group (P<0.01, P<0.05). There was no significant difference between the EA group and the ibuprofen group in the above indexes (P>0.05). EA could alleviate pain and uterine tissue injury in rats with PDM. The mechanism may be related to the inhibition of the activation of NLRP3 inflammasome in rat uterine tissues, thereby inhibiting pyroptosis and its inflammatory factors release.

Effect of electroacupuncture intervention on relieving pain and inflammation by suppressing TLR4/NF-κB signaling in rats with primary dysmenorrhea

To investigate the mechanism of electroacupuncture(EA) intervention in rats with primary dysmenorrhea(PDM) based on the Toll-like receptor 4(TLR4)/nuclear factor(NF)-κB signaling pathway. Forty female SD rats were randomly divided into blank control, model, EA and medication groups, with 10 rats in each group. PDM rat model was established by subcutaneous injection of estradiol benzoate combined with intraperitoneal injection of oxytocin. At the same time of model procedures, EA(50 Hz, dense wave) was applied to "Guanyuan" (CV4) and bilateral "Sanyinjiao" (SP6) of rats in the EA group, with needles retained for 20 min, for 10 consecutive days. Rats in the medication group received ibuprofen(125 mg/100 mL, 0.8 mL) by gavage for 10 consecutive days. At the 11th day, writhing behavior of rats was assessed. Uterine morphology was observed by eyes and uterine pathological changes were observed after HE staining. Content of prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α) in serum and uterine tissues was detected by ELISA; NF-κB p65 positive expression in nucleus was detected by immunofluorescence; protein expression levels of TLR4, NF-κB p65, p-NF-κB p65 and inflammatory factors interleukin (IL) -1β and IL-18 were detected by Western blot. After modeling, uterus tissues were congested and edematous, with necrosis of luminal epithelium, severe edema and extensive shedding of endometrium, nuclear pyknosis, fragmentation and disappearance, neutrophils infiltration, and slight expansion of glandular cavity, which was milder in the EA and the medication groups. Compared with the blank control group, writhing times, scores and incubation period, HE pathological scores, PGF2α contents in serum and uterine tissues, ratio of NF-κB p65 positive expression in nucleus, TLR4, NF-κB p65, p-NF-κB p65, IL-1β and IL-18 protein expression levels in uterine tissues of rats in the model group were all significantly increased(P<0.01), while PGE2 contents in serum and uterine tissues were significantly decreased(P<0.01). Compared with the model group, writhing times and scores, HE pathological scores, PGF2α contents in serum and uterine tissues, ratio of NF-κB p65 positive expression in nucleus, TLR4, NF-κB p65, p-NF-κB p65, IL-1β and IL-18 protein expression levels in uterine tissues of rats in the EA and medication group were all significantly decreased(P<0.01), while writhing incubation period, PGE2 contents in serum and uterine tissues were significantly increased(P<0.05, P<0.01). EA intervention could relieve inflammatory response and pain in PDM rats, which may be related to its effect in reducing TLR4 expression, inhibiting NF-κB activation and down-regulating inflammatory factors levels of IL-1β and IL-18.

Alleviation effect of conjugated linoleic acid on estradiol benzoate induced fatty liver hemorrhage syndrome in Hy-line male chickens.

The purpose of this study was to explore whether conjugated linoleic acid (CLA) could alleviate fatty liver hemorrhagic syndrome (FLHS) induced by estradiol benzoate intramuscular injection in laying hens. One hundred male Hy-Line white chickens were randomly divided into two groups, namely, the control (CON) and estradiol benzoate (E) groups, and both groups were fed the same basal diet. After injections of estradiol benzoate at 2 mg/kg every two days for a total of 7 times, chickens in the E group showed FLHS symptoms, including liver enlargement, hemorrhage, and steatosis. Then half of the chickens in the E group received an additional diet containing 5000 mg/kg CLA for 8 weeks. The results of morphological observations, hematoxylin and eosin staining, and Oil Red O staining showed that CLA alleviated liver enlargement, hemorrhage, and lipid accumulation in FLHS chickens. In addition, we measured liver function and lipid metabolism indicators, including ALT, AST, TG, TCH, HDL-C, and LDL-C, which further suggested that CLA mitigated the disturbance of serum and liver metabolism in FLHS chickens. Mechanistically, CLA inhibited hepatic de novo lipogenesis, cholesterol synthesis, and TG accumulation and increased TG hydrolysis in FLHS chickens by regulating the gene expression of CD36, ACC, FAS, SCD 1, DGAT2, LIPE, ATGL, CPT1A, SREBP-1c, SREBP-2, PPARγ, and PPARα. Furthermore, CLA ameliorated hepatic oxidative stress and inhibited NF-κB signaling pathway-mediated inflammation in FLHS chickens. In conclusion, CLA regulated lipid metabolism, thus further alleviating oxidative stress and inflammation to alleviate FLHS induced by estrogen in chickens.

Comparison of Estradiol Cypionate, Estradiol Benzoate and Gonadotropin-Releasing Hormone in Fixed-Time Artificial Insemination in Multiparous Murrah Buffaloes

The present study was aimed to evaluate the efficiency of estradiol cypionate, estradiol benzoate and gonadotropin-releasing hormone during fixed-time artificial insemination (FTAI) protocols in multiparous Murrah buffaloes. A total of 35 buffaloes were used between September and November 2021 and subjected to a synchronization protocol. On day 0, insertion of an intravaginal progesterone device (CIDR, 1.38 g) was made with intramuscular (i/m) injection of estradiol benzoate (EB, 2 mg); On day 9: CIDR removed with i/m injections of Dinoprost (12.5 mg) and eCG (400 IU), and then buffaloes were randomized into three treatment group: 1) EB 1 mg on day 10 (n=13). 2) estradiol cypionate (EC) 1 mg on day 9 (n=12), and 3) Buserelin acetate (GnRH) 0.0105 mg on day 10 (n=10). The estrus signs observed during the FTAI (56 h after CIDR withdrawal) and conception rate at 90 days after FTAI were recorded. The conception rates were 61.5, 58.3 and 60.0% for EB, EC and GnRH treatment groups, respectively. There was no significant difference between the treatment groups for conception rate and signs of estrus. Therefore, it was concluded that all three treatments can be efficiently used during estrus synchronization protocol with FTAI in multiparous Murrah buffaloes.

Effect of different acupuncture and moxibustion methods on uterine contraction and microcirculation in cold congealing dysmenorrhea rats

To observe and compare the effects of different acupuncture and moxibustionmethods at "San-yinjiao" (SP6) on uterine contraction and microcirculation in cold congealing dysmenorrhea rats, so as to explore its mechanism underlying treatment of dysmenorrhea. A total of 140 female SD rats were randomly divided into normal control, mo-del, perpendicular needling, transverse needling and moxibustion groups, with 28 rats in each group. The cold congealing dysme-norrhea rat model was prepared by exposure in a freezer (25 ℃) for 4 h, once daily for 5 days, and subcutaneous injection of estradiol benzoate (once daily for 10 days) and intra-abdominal injection of oxytocin (once). For rats in three intervention groups, acupuncture needles were inserted into bilateral SP6 perpendicularly or transversely to a depth of 4~5 mm and retained for 20 min, or moxibustion was applied to SP6 for 20 min. The uterine contraction degree and the uterine microcirculation were recorded. The expression levels of transient receptor potential vanilloid 1 (TRPV1) and heat shock protein 70 (HSP70) in local tissues of SP6 area were detected by immunohistochemistry. The expression levels of μopioid receptor and endothelin 1 (ET1) mRNA in the uterus were assessed by quantitative real time-PCR. After modeling and compared with the normal control group, the number and peak-to-peak values of uterine contraction waves, and uterine motility were significantly increased (P<0.01,P<0.05), while the speed of blood flow in the microvessels was slowed down (P<0.01), diameters of the uterine microvessels and capillaries (cap) shrank obviously (P<0.01) in the model group. After the intervention, all indexes of uterine contraction and microcirculation were improved in three intervention groups (P<0.01, P<0.05), while transverse needling and moxibustion showed better effects compared to perpendicular needling (P<0.05, P<0.01). The expression of TRPV1 and HSP70 in SP 6 area had no significant changes (P>0.05), while the uterine μopioid receptor mRNA expression decreased (P<0.01), and ET1 mRNA expression increased (P<0.01) in the model group relevant to the normal control group. Following the intervention, the expression levels of TRPV1 and HSP70 in SP6 area were increased (P<0.05, P<0.01), and expression levels of uterine μopioid receptor mRNA increased (P<0.05, P<0.01) and uterine ET1 mRNA decreased (P<0.05, P<0.01) in the three intervention groups. The effect of moxibustion was considerably better than those of two acupuncture groups in up-regulating TRPV1 expression (P<0.05). Both transverse needling and moxibustion showed better effects of down-regulating uterine ET1 mRNA expression than perpendicular needling (P<0.01). Transverse needling and moxibustion at SP6 have a better effect of relieving ute-rine contraction and improving uterine microcirculation than perpendicular needling, which may be related to their effects in up-re-gulating the expression of TRPV1 and HSP70 in SP6 area, thereby modulating the mRNA expression of μ opioid receptor and ET1 in uterine tissue.

Establishment and comparison of two methods to produce a rat model of mammary gland hyperplasia with hyperprolactinemia

This study aimed to establish and compare models of mammary gland hyperplasia (MGH) with hyperprolactinemia (HPRL) using two different methods. The models provide information on the relationship between mammary gland hyperplasia and associated hormones. Model A was constructed using intramuscular injections of estradiol benzoate injection (EBI), followed by progesterone (P), and then metoclopramide dihydrochloride (MDI). Model B was designed by administering MDI, follow by EBI, and then P intramuscularly. Model B showed higher MGH progression compared with model A. Notably, increase in estradiol (E2) was negatively correlated with prolactin (PRL) secretion. However, PRL levels in model B were significantly higher compared with the levels in model A. Estrogen (ER), prolactin receptor (PRLR), and progesterone receptor (PR) mRNA and protein expression levels in model B rats were positively correlated with changes in the corresponding hormone levels. However, E2, P, and PRL levels in model A showed no direct relationship with levels of the mRNAs of related hormones and protein expression levels. Our results suggest that model B is an appropriate model of MGH with HPRL that can be used to perform further studies about the interactions of the E2, P, and PRL hormones in this disorder.

Conception Rate of Pre-synchronization and Two Short Term Heat-synch Programs using Two Doses of PGF2α in Lactating Holstein Dairy Cows

BACKGROUND: Improving the reproductive performance of dairy cows requires manipulation of estrus using estrus synchronization protocols. OBJECTIVES: The aim of this study was to evaluate the effect of reducing the length of estrus synchronization protocol by using two doses of prostaglandin injection on reproductive performance of Holstein dairy cows. METHODS: At first, all cows received GnRH (day 0), PGF2α on day 7, and GnRH on day 17. Then, cows assigned randomly to one of 3 groups: Group 1) PGF2α injection on days 22 and 23, estradiol benzoate injection on day 24. Group 2) PGF2α injection on days 23 and 24, estradiol benzoate injection on day 25. Group 3) Control group; injection of PGF2α on day 24, injection of estradiol benzoate on day 25. Estrus detection was performed twice a day up to 48 hours (AM/PM) using signs of estrus and fixed time AI protocol was used after 48 hours (if not previously inseminated). RESULTS: Conception rate in group 2 were significantly higher than control group (P≤ 0.05) and tended to be higher than group 1 (P= 0.079). CONCLUSIONS: The results confirmed the hypothesis that a decrease in the period of follicle dominance by reducing the interval between GnRH and PGF2α through using two injections of PGF2α improved fertility of lactating dairy cows.

Tibolone induces lordosis behavior, but not concurrent or sequential inhibition, in Sprague Dawley rats

Activation of progesterone receptor (PR) facilitates lordosis 40 hr after estradiol treatment, but induces concurrent inhibition (CI) when given with estradiol, or sequential inhibition (SI) when given subsequent to the faciliatory time interval. Tibolone (TBL) is a broad spectrum gonadal steroid agonist that facilitates lordosis when given after estradiol and in place of progesterone (P). The present experiment examined whether it can also induce CI or SI of lordosis behavior in rats as a means of determining its dominant receptor mechanism of action. Subcutaneous (SC) injections of estradiol benzoate (EB), TBL, or P were varied in time to examine whether P induced CI in females pre-treated with TBL or EB, or whether P or TBL induced CI when injected prior to EB (Experiment 1); whether P or TBL induced SI after EB treatment (Experiment 2); and whether P induced SI after TBL treatment (Experiment 3). In Experiment 1, P injected 1 h before EB induced CI after a second P administration 40 h later. However, the same treatment of P to females primed with TBL did not induce CI. In Experiment 2, injections of P or TBL 40 h after EB or TBL induced lordosis within 4 h (facilitation test); however, a second injection of P, 24 h later, induced significant lordosis in rat pretreated with TBL, but not in rats pretreated with P (inhibition test). In Experiment 3, P injected 40 hs after different doses of TBL induced intense lordosis behavior (facilitation test); however, a second dose of P injected 64 h later induced SI, but not in females primed with the highest dose of TBL (inhibition test). Unlike P, TBL did not induce CI or SI. This suggests that TBL likely induces its facilitation of lordosis by an action that is independent of PR.

Effect of proximal and distal acupoint catgut-embedding on uterus prostaglandin, serum IL-2 and splenic NK cell activity in primary dysmenorrhea rats

To observe the effect of proximal and distal acupoint catgut-embedding on the contents of prostaglandin E2 (PGE2) and prostaglandin F2α(PGF2α) in the uterus, serum Interleukin-2 (IL-2) contents and splenic natural killer (NK) cell activity in primary dysmenorrhea (PD) rats，so as to explore the different effects of proximal and distal acupoint catgut-embedding on PD rats. Female Wistar rats were randomly divided into control, model, proximal catgut-embedding and distal catgut-embedding groups, with 8 rats in each group. The PD model was established by subcutaneous injection of estradiol ben-zoate (0.5 mg/rat on the first day and 10th day, and 0.2 mg/rat from the 2nd to the 9th day) and intraperitoneal injection of oxytocin (2 U/rat, on the 11th day). Catgut-embedding was applied at bilateral "Guanyuan"(CV4) and "Ciliao"(BL32) in the proximal catgut-embedding group, and bilateral "Sanyinjiao" (SP6) and "Diji"(SP8) in the distal catgut-embedding group. After the treatment, the body writhing times in 30 min and uterine mass were recorded, PGE2 and PGF2αin uterus and IL-2 in serum were assayed by using ELISA, the activity of NK cell in the spleen was detected using MTT colorimetry. Following modeling, the body writhing times of the model group was increased than that of the control group (P<0.01); After interventions, the body writhing times were decreased in the proximal and distal catgut-embedding groups than those of the model group (P<0.01). Compared with the control group, the uterine mass and uterus PGF2α content were increased (P<0.01), while uterus PGE2, serum IL-2 and splenic NK cell activity were decreased (P<0.01) in the model group. After interventions, the uterine mass and uterus PGF2α were down-regulated (P<0.01, P<0.05), while the contents of uterus PGE2, serum IL-2 and splenic NK cell activity up-regulated (P<0.01) in the proximal and distal catgut-embedding groups in contrast to the model group. The content of uterus PGF2α was down-regulated (P<0.05) and splenic NK cell activity was up-regulated (P<0.01) in the proximal catgut-embedding group than those of the distal catgut-embedding group. Both proximal and distal acupoint catgut-embeding can increase PGE2 and decrease PGF2α in the uterus, increase the level of serum IL-2 and the activity of NK cells in the spleen in PD model rats, thereby achieving analgesic effect. The effect of proximal catgut-embedding is better than that of distal catgut-embedding.

Perpendicular and transverse needling of "Sanyinjiao" (SP6) relieves abdominal pain by regulating arginine vasopressin and its receptor expression levels in uterus and hypothalamus in cold-stasis type dysmenorrhea rats

To observe the effect of perpendicular and subcutaneous transverse needling at "Sanyinjiao" (SP6) on visceral pain behavior, arginine vasopressin (AVP) content in the serum, uterine tissues, spinal cord and hypothalamus and expression of AVP receptors AVPR1A and AVPR1B in the uterine tissues, spinal cord and hypothalamus in cold-stasis (stasis due to pathogenic cold) type dysmenorrhea rats, so as to explore their mechanisms underlying pain relief. Forty female SD rats were randomly divided into blank control, model, perpendicular needling and transverse needling groups, with 10 rats in each group. The cold-stasis dysmenorrhea rat model was established by exposure in a freezer (-25 ℃) for 4 h, once daily for 5 days, and subcutaneous injection of estradiol benzoate (once daily for 10 days) and intra-abdominal injection of oxytocin injection (once). For rats of the two acupuncture groups, acupuncture needles were inserted into the bilateral SP6 perpendicularly or transversely to a depth of about 4-5 mm, and retained for 20 min. The abdominal pain behavior was assessed by recording the writhing latency and scaling the rats' writhing reactions after modeling. The contents of AVP in the serum, uterus, spinal cord and hypothalamus tissues were assayed using ELISA and the expression of AVPR1A and AVPR1B in the uterus, spinal cord and hypothalamus was measured by using Western blot and quantitative real time-PCR, respectively. After mode-ling and compared with the blank control group, the writhing latency was significantly shortened (P<0.05), and the writhing score in the first 20 min was significantly increased (P<0.01) in the model group. After the intervention, the writhing latency was significantly prolonged (P<0.01), and the writhing scores in 20 min were significantly decreased (P<0.01) in the two needling groups. The AVP contents were obviously increased in the serum and uterine tissue (P<0.05, P<0.01) but decreased appa-rently in the spinal cord and hypothalamus tissues (P<0.01, P<0.05), and the expression levels of AVPR1A or AVPR1B protein and mRNA were markedly increased in the uterine tissues (P<0.01, P<0.05), and significantly decreased in the spinal cord and hypotha-lamus in the model group relevant to the control group (P<0.05, P<0.01). Following the intervention, The AVP content in the serum of the perpendicular needling group (P<0.05) and that in the uterus of the two needling groups were significantly decreased (P<0.01), as well as that in the hypothalamus was obviously increased in the two needling groups (P<0.05). The expression levels of AVPR1A protein and mRNA in the uterus were significantly down-regulated in the two needling groups (P<0.01, P<0.05) and AVPR1B protein in the hypothalamus of the perpendicular needling group was up-regulated (P<0.05). Moreover, no significant differences were found between the two needling groups in regulating the related indexes mentioned above (P>0.05). Both perpendicular and subcutaneous transverse needling at SP6 have an immediate analgesic effect in cold-stasis type dysmenorrhea rats, which may be related to their effects in regulating AVP levels and its receptor expression in the uterine and hypothalamus.

Effect of acupoint catgut embedding on levels of PG-related factors and NF-κB proteins in ute-rine tissues of rats with primary dysmenorrhea

To observe the effect of acupoint catgut embedding on levels of prostaglandin F2α(PGF2α), cyclooxygenase-2(COX-2) and nuclear factor kappa B(NF-κB) in the uteruses of rats with primary dysmenorrhea (PD), so as to explore its mechanisms underlying improvement of PD. Forty female SD rats were randomly divided into normal, model, acupoint catgut embedment and medication groups, with 10 rats in each group. The PD model was established by subcutaneous injection of estradiol benzoate (0.5 mg on the 1st day, and 0.2 mg thereafter) once daily for 10 days, followed by i．p. of oxytocin 2 U(0.5 mg•5 U－1•mL－1) on the 11th day. Catgut embedment was applied to "Guanyuan"(CV4) and "Sanyinjiao"(SP6) on day 1 and 5 while modeling, and rats of the medication group received gavage of ibuprofen (1.25 mg/mL, 0.8 mL/rat) once daily for 10 d. The level of PGF2αin the uterus tissuewas assayed by ELISA, and the expression levels of uterine COX-2, phospho (p)-NF-κB p65, NF-κB p65 proteins were detected by Western blot. Compared with the normal group, the levels of PGF2α， COX-2, p-NF-κB p65 and NF-κB p65 in the uterine tissues were significantly increased in the model group (P<0.05). Compared with the model group, the levels of PGF2α and COX-2 in both catgut embedment and medication groups as well as p-NF-κB p65 in the catgut embedment group were significantly decreased (P<0.05). Compared with the medication group, the level of p-NF-κB 65 in the catgut embedment group was significantly decreased (P<0.05). The analgesic effect of acupoint catgut embedding may be related to its effects in down-regulating the expression of p-NF-κB and the levels of COX-2 and PGF2αin uteruses of PD rats.

Repeated trans-cervical embryo recoveries in Santa inês ewes subjected to short- or long-term superovulatory treatment regimens

Outcomes of short- (6.5 days) and long-term (14.5 days) estrous synchronization for 6.5 d (G-6.5d) or 14.5 d (G-14.5d) and followed by the 4-day or 3-day declining-dose follicle-stimulating hormone superovulatory regimen, respectively, were compared using 16 estrous-cycling Santa Inês ewes. Non-surgical embryo recovery (NSER) procedures were performed 60 d apart starting 6 or 7 d after the onset of estrus; an i.m. injection of estradiol benzoate and of d-cloprostenol at 16 h was followed by an i.v. oxytocin injection administered 20 min before NSER. There was a longer (P < 0.05) period before estrous onset in ewes during the second (September) compared with the first study replicate (July) by approximately 14 h. The NSER could be performed in 11 of 15 ewes that were in estrus, with an average of three viable-embryos/donor and the mean duration of the procedure being 29 min. There were no differences in superovulatory responses between the two groups of ewes, but there were only degenerated embryos in ewes of the G-6.5d group. In summary: i. the duration of progestin-priming and of multiple-dose pFSH treatment had a limited effect on superovulatory responses in estrous-cycling Santa Inês ewes; ii. NSER is a safe and repeatable method of embryo collection in ewes subsequent to superovulation; and iii. duration of the superovulatory treatment regimen may alter the effects of endogenous steroids on oocyte/embryo quality in ewes.

Dynorphin and GABAA Receptor Signaling Contribute to Progesterone's Inhibition of the LH Surge in Female Mice.

Progesterone can block estrogen-induced luteinising hormone (LH) surge secretion and can be used clinically to prevent premature LH surges. The blocking effect of progesterone on the LH surge is mediated through its receptor in the anteroventral periventricular nucleus (AVPV) of the hypothalamus. However, the underlying mechanisms are unclear. The preovulatory LH surge induced by estrogen is preceded by a significant reduction in hypothalamic dynorphin and gamma-aminobutyric acid (GABA) release. To test the detailed roles of dynorphin and GABA in an LH surge blockade by progesterone, ovariectomized and 17β-estradiol capsule-implanted (OVX/E2) mice received simultaneous injections of estradiol benzoate (EB) and progesterone (P) or vehicle for 2 consecutive days. The LH level was monitored from 2:30 pm to 8:30 pm at 30-minute intervals. Progesterone coadministration resulted in the LH surge blockade. A continuous microinfusion of the dynorphin receptor antagonist nor-BNI or GABAA receptor antagonist bicuculline into the AVPV from 3:00 pm to 7:00 pm reversed the progesterone-mediated blockade of the LH surge in 7 of 9 and 6 of 10 mice, respectively. In addition, these LH surges started much earlier than the surge induced by estrogen alone. However, 5 of 7 progesterone-treated mice did not show LH surge secretion after microinfusion with the GABAB receptor antagonist CGP-35348. Additionally, peripheral administration of kisspeptin-54 promotes LH surge-like release in progesterone treated mice. These results demonstrated that the progesterone-mediated suppression of the LH surge is mediated by an increase in dynorphin and GABAA receptor signaling acting though kisspeptin neurons in the AVPV of the hypothalamus in female mice.