Non-pregnant Female Rats Research Articles

Long‐Term Effect of Deslorelin Implant on Ovarian Pre‐Antral Follicles and Uterine Histology in Female Rats

The objective of the present study was to investigate the inhibitory effects of long-term deslorelin implant administration on the ovarian and uterine structures of female rats. A total of 16 non-pregnant female rats were randomly assigned to two groups, each consisting of eight animals. Animals in the implant group (DESL) received subcutaneously (s.c.) a single deslorelin implant (4.7 mg), an analogue of GnRH, while no treatment was applied to the control group (CON). A single adult male rat was introduced into the cages of both the DESL and CON females after 6 weeks of implant administration. After 1 year of implant administration, all animals were killed and follicular structures and volumes of ovaries and uterus were examined using stereological methods. Stereological observations showed that the mean ovarian total volume of the DESL group (0.28 ± 0.07 cm(3)) was lower than that of the CON group (1.55 ± 0.23 cm(3)) (p < 0.001). On the other hand, the total number of pre-antral follicles in the ovaries of DESL (555.32 ± 151.47) females were significantly lower than the control group (1162.96 ± 189.19) (p < 0.001). In the DESL group, the mean volumes of epithelium, endometrium, myometrium and total volume of the uterus were significantly (p < 0.001) lower than in the control groups. In conclusion, these findings indicate that the long-term deslorelin implant (i) interferes with the normal cyclicity of female rats and (ii) affects the pre-antral follicle population. Further studies will be required to determine the effects of long-term deslorelin treatment on the pre-antral follicle numbers and future fertility in other species.

Comparative experimental study on multiple organ damage between pregnant rats and non-pregnant rats with severe acute pancreatitis

Objective To observe the functional changes and the histopathological changes of multiple organs in pregnant rats and non-pregnant female rats with severe acute pancreatitis (SAP).Methods Pregnant SD rats were randomly divided into pregnancy group and SAP group,and non-pregnant female rats were randomly divided into sham operation group (SO group) and SAP group.Rats were killed at 3rd,6th and 12th h.Serum amylase (AMY),liver function [ alanine transaminase (ALT),aspartate aminotransferase (AST) ],and renal function [ creatinine ( Cr),blood urea nitrogen ( BUN ) ]were detected.The pathological changes in the pancreas,liver,kidney,lung and heart tissues were observed.Results Amylase and histological scores of the pancreas at 3rd,and 6th h were higher significantly in SAP group of pregnant rats than those in SAP group (P ＜ 0.05).Liver function levels at each time point were higher significantly in SAP group of pregnant rats than those in SAP group [3 h:ALT (128.38 ±24.92) vs (99.75 ±16.27) U/L,AST (261.25 ±64.98) vs (194.50 ±49.00) U/L,Cr (52.38±8.99) vs (41.88 ±7.28) μmol/L,BUN (8.63 ± 1.24) vs (7.11 ± 1.29) mmol/L,P ＜ 0.05 ].Histological scores of the liver and kidneys at 3rd and 6th h (6 h:liver 2.13 ±0.44 vs 1.56 ±0.49,kidney 5.25 ± 1.28 vs 3.88 ±1.13,P ＜ 0.05),and those of the lungs at 12th h (5.00 ± 0.85 vs 3.75 ± 0.49,P ＜ 0.05 ) were higher significantly in SAP group of pregnant rats than in SAP group.Conclusion Compared with non-pregnant rats,the pancreatitis occurring in pregnant rats is more acute and more severe,and multiple organ damage occurs earlier and more severe. Key words: Pregnancy; Severe pancreatitis; Multiple organ injury

Toxicokinetic Profile of N-(2-Aminoethyl)ethanolamine in the Female Wistar Rat and Distribution into the Late Gestation Fetus and Milk

N-(2-aminoethyl)ethanolamine (AEEA) caused aneurysms of the great vessels in rats exposed in utero and during the first days post partum, exacerbated by postnatal treatment of the lactating dams (Moore et al., 2012). The purpose of this work was to examine the systemic availability of AEEA during gestation and early lactation. The absorption of AEEA was determined following oral administration to nonpregnant and pregnant female Wistar rats. A single dose administered by gavage (0.5 or 50 mg/kg) on gestation day 18 was rapidly and extensively (>90%) absorbed from the gastrointestinal tract (absorption t(1/2) = 0.1-0.2 hr). Elimination from the plasma followed a biphasic pattern, with a rapid elimination phase (t(1/2 α) = 1.6-1.8 hr) followed by a slower phase (t(1/2 β) = 16.7-17.3 hr). Following repeated gavage administration during gestation day 17 to 19, (14) C-AEEA-derived radioactivity readily partitioned into the fetus and was evenly distributed therein, but cleared approximately twofold slower from the fetal blood and tissues than the maternal blood and chorioallantoic placenta. When administered to lactating dams during lactation days 1 to 12, (14) C-AEEA-derived radioactivity preferentially partitioned into the milk reaching levels that were between 1.6- and 2.5-fold higher than the maternal blood. Although the concentration of AEEA equivalents in the maternal blood remained quite consistent, the concentration in the milk fell by almost 40% between lactation days 4 and 12, probably reflecting an increase in milk production over this same period. We confirm exposure of the offspring to AEEA both in utero and during lactation, but that AEEA does not appear to specifically concentrate in the great vessels.

Chondroregulatory action of prolactin on proliferation and differentiation of mouse chondrogenic ATDC5 cells in 3-dimensional micromass cultures

A recent investigation in lactating rats has provided evidence that the lactogenic hormone prolactin (PRL) increases endochondral bone growth and bone elongation, presumably by accelerating apoptosis of hypertrophic chondrocytes in the growth plate and/or subsequent chondrogenic matrix mineralization. Herein, we demonstrated the direct chondroregulatory action of PRL on proliferation, differentiation and apoptosis of chondrocytes in 3-dimensional micromass culture of mouse chondrogenic ATDC5 cell line. The results showed that ATDC5 cells expressed PRL receptor (PRLR) transcripts, and responded typically to PRL by downregulating PRLR expression. Exposure to a low PRL concentration of 10ng/mL, comparable to the normal levels in male and non-pregnant female rats, increased chondrocyte viability, differentiation, proteoglycan accumulation, and mRNA expression of several chondrogenic differentiation markers, such as Sox9, ALP and Hspg2. In contrast, high PRL concentrations of ⩾100ng/mL, comparable to the levels in pregnancy or lactation, decreased chondrocyte viability by inducing apoptosis, with no effect on chondrogenic marker expression. It could be concluded that chondrocytes directly but differentially responded to non-pregnant and pregnant/lactating levels of PRL, thus suggesting the stimulatory effect of PRL on chondrogenesis in young growing individuals, and supporting the hypothesis of hypertrophic chondrocyte apoptosis in the growth plate of lactating rats.

Comparative Analysis of the Effects of Various Stress Factors at the Stage of Early Organogenesis on Heart Rate Variability in Pregnant Female Rats and Their Offspring

We studied changes in the autonomic balance of heart regulation (by the parameters of heart rate variability) in non-pregnant female rats and rats on the days 10-11 of pregnancy on the next day after stress provoked by acute hypobaric hypoxia, intermittent normobaric hypoxia, or immobilization. The same parameters were assessed in 36-day-old offspring. In non-pregnant rats, the intermittent hypoxia resulted in a shift of the autonomic balance of heart regulation towards activation of the parasympathetic nervous system; in pregnant females, immobilization led to a shift of the autonomic balance towards the sympathetic nervous system. In the offspring, the changes also depended on the type of stress.

Reduction of postoperative adhesions by trimetazidine: an experimental study in a rat model

Trimetazidine (TMZ) reduces intracellular acidosis and inhibits oxygen-derived free radicals and neutrophile infiltration in ischemia and hypoxia, which are the primary steps of adhesion formation. Our aim is to study the anti-adhesion potential of trimetazidine in a rat uterine horn model. Forty non-pregnant female Wistar-Albino rats were randomly assigned, with ten in each group, to receive 2 ml saline, or 5 mg/kg intraperitoneal trimetazidine postoperatively, and control and sham. TMZ was administered to TMZ postoperative group 5 mg/kg i.p. daily for 5 days after the operation. Both uterine horns were exposed, and then a 2 cm segment of the anti-mesenteric surface of both the uterine horns were traumatized in 10 spots with unipolar electrocautery for 2 s with a power of 50 Watts. All the animals were killed by lethal dose of ether on postoperative 14th day. Intraperitoneal adhesions were scored by clinical adhesion scoring system, and histological and morphometric analysis was performed. Total adhesion score (TAS) of control group was 10 while the sham group was found to be 0. TAS of the placebo group that was given saline (TAS 5), and postoperative TMZ applied group (TAS 3.5) were significantly lower than the control group (p < 0.05). The severity scores of postoperative TMZ and sham groups were significantly smaller than the other groups (p < 0.05). TMZ significantly reduced the extent and severity of horn adhesions. The promising efficacy demonstrated by the intraperitoneal TMZ in this model warrants further investigation in clinical trials focused on gynecological procedures.

Quasi-Experimental Designs in Practice-based Research Settings: Design and Implementation Considerations

Although randomized controlled trials are often a gold standard for determining intervention effects, in the area of practice-based research (PBR), there are many situations in which individual randomization is not possible. Alternative approaches to evaluating interventions have received increased attention, particularly those that can retain elements of randomization such that they can be considered "controlled" trials. Methodological design elements and practical implementation considerations for two quasi-experimental design approaches that have considerable promise in PBR settings--the stepped-wedge design, and a variant of this design, a wait-list cross-over design, are presented along with a case study from a recent PBR intervention for patients with diabetes. PBR-relevant design features include: creation of a cohort over time that collects control data but allows all participants (clusters or patients) to receive the intervention; staggered introduction of clusters; multiple data collection points; and one-way cross-over into the intervention arm. Practical considerations include: randomization versus stratification, training run in phases; and extended time period for overall study completion. Several design features of practice based research studies can be adapted to local circumstances yet retain elements to improve methodological rigor. Studies that utilize these methods, such as the stepped-wedge design and the wait-list cross-over design, can increase the evidence base for controlled studies conducted within the complex environment of PBR.

Effect of bevacizumab on postoperative adhesion formation in a rat uterine horn adhesion model and the correlation with vascular endothelial growth factor and Ki-67 immunopositivity

We investigated whether adhesion formation is prevented by the inhibition of angiogenesis in a rat uterine horn adhesion model. A single-dose of bevacizumab was effective in preventing postoperative intraperitoneal adhesion formation among 30 Wistar albino rats that underwent serosal injury by use of a standard technique after laparotomy with intraperitoneal bevacizumab.

Effects of endogenous glucocorticoid secretion on the interleukin-6 response to bacterial endotoxin in pregnant and non-pregnant rats

Glucocorticoids (GCs) are released in response to immune activation by the bacterial endotoxin, lipopolysaccharide (LPS). However, GC secretion in response to immune activation and other stressors is attenuated at term of pregnancy. GCs are important modulators of the immune response, and both pro- and anti-inflammatory effects are described. Here, we examined whether GC secretion in response to LPS is maintained in earlier pregnancy before term, and investigated the role of endogenous GCs in modulating LPS-induced circulating cytokines, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), in pregnant compared to non-pregnant female rats. Plasma corticosterone (Cort) and ACTH responses to LPS were well maintained in pregnant rats at embryonic days 15/16 (E15/16) and E18/19 compared to non-pregnant rats. At E19, maternal LPS administration increased fetal plasma Cort and decreased testosterone in male fetuses. In non-pregnant animals, pretreatment with the GC synthesis inhibitor, metyrapone, inhibited the LPS-induced increase in IL-6, and the IL-6 response was restored by Cort replacement, indicating that LPS induction of IL-6 is Cort-dependent. In E15 pregnant animals, metyrapone had no effect on LPS-induced IL-6 levels, indicating that LPS-induction of IL-6 is not dependent on Cort. These contrasting patterns of IL-6 induction in non-pregnant and pregnant animals were reflected in levels of hypothalamic Socs3 mRNA, an indicator of IL-6 signaling pathway activation. In both non-pregnant and pregnant rats, LPS-induced plasma TNF-α responses were inhibited by metyrapone but not re-instated by Cort replacement. It is suggested that altered GC regulation of IL-6 may be required to sustain specialized functions of IL-6 during pregnancy.

Chronic vasodilation produces plasma volume expansion and hemodilution in rats: consequences of decreased effective arterial blood volume.

Plasma volume (PV) expansion is required for optimal pregnancy outcomes; however, the mechanisms responsible for sodium and water retention in pregnancy remain undefined. This study was designed to test the "arterial underfill hypothesis" of pregnancy which proposes that an enlarged vascular compartment (due to systemic vasodilation and shunting of blood to the placenta) results in renal sodium and water retention and PV expansion. We produced chronic vasodilation by 14 days administration of nifedipine (NIF; 10 mg·kg(-1)·day(-1)) or sodium nitrite (NaNO2; 70 mg·kg(-1)·day(-1)) to normal, nonpregnant female Sprague-Dawley rats. Mean arterial pressure, monitored by telemetry, was reduced by both NIF and NaNO2 but was unchanged in control rats. At day 14, vasodilator treatment lowered hematocrit and increased PV (determined by Evans blue dye dilution). Plasma osmolarity (Posm), sodium (PNa), and total protein concentrations all fell. These responses resemble the responses to normal pregnancy with hemodilution, marked PV expansion, and decreased Posm and PNa. Our previous work indicates a role of increased inner medullary phosphodiesterase-5 (PDE5) in the sodium retention of pregnancy. Here, we found that inner medullary PDE5A mRNA and protein expression were increased by both NIF and NaNO2 treatment vs. control; however, neither renal cortical nor aortic PDE5 expression was changed by vasodilator treatment. We suggest that a primary, persistent vasodilation drives increased inner medullary PDE5 expression which facilitates continual renal Na retention causing "refilling" of the vasculature and volume expansion.

Effect of the ethanolic extract of Nauclea latifolia (Family: Rubiaceae) on the isolated uterus of non-pregnant rats

The plant Nauclea latifolia has been reported to be used by traditional healers to arrest pre-term labour. The ethanolic extract of the root of N. latifolia was screened for activity via agonist–induced contractions of uterine smooth muscles in non-pregnant female albino rats. The extract, at 0.1 and 0.2 mg/ml (final bath concentration), was tested against oxytocin (4×10-5 to 8×10-2 I.U/ml: final bath concentration), acetylcholine (0.04 to 40 μg/ml: final bath concentration) and ergometrine (0.05 to 100 μg/ml: final bath concentration) induced contractions invitro. The effect of the extract was compared to that of (0.004 μg/ml: final bath concentration) salbutamol and (0.004 μg/ml: final bath concentration) atropine. Both concentrations of the extract significantly shifted the concentration response curves of oxytocin (P<0.01), acetylcholine (P<0.0001) and ergometrine (P<0.0001) to the right with a slight depression of the Emax. This shift was more with the 0.2 mg/ml concentration, thus suggesting the possibility of a dose dependent action. There was no statistical significant decrease in Emax by 0.1 mg/ml of the extract, while the 0.2 mg/ml produced a significant depression (P<0.05) of the Emax, which like salbutamol could not be overwhelmed by higher concentrations of oxytocin. Similarly a significant reduction of the Emax of acetylcholine induced contractions was produced by 0.2 mg/ml, while both concentrations (0.1 and 0.2 mg/ml) produced significant (P<0.0001) reduction in Emax of ergometrine. It can thus be concluded that N latifolia root extractreduces oxytocin, acetylcholine and ergometrine-induced uterine contractions. These inhibitions were non-competitive. The result indicates an anti-abortifacient property. Key words: Antagonism, Nauclea latifolia, root extract, uterine-contraction, uterus

Leptin modulates noradrenaline release in the paraventricular nucleus and plasma oxytocin levels in female rats: A microdialysis study

The neural control and mutual interrelationships among individual factors involved in the regulation of food intake and simultaneously related to reproduction are far from being understood. We have suggested that at least some of the effects of orexigenic and anorexigenic peptides might be mediated via noradrenalin release in the paraventricular nucleus (PVN). The main hypothesis was that leptin has an inhibitory action on oxytocin secretion and hypothalamic release of noradrenalin. Non-pregnant female rats in their diestrus were subjected to cannulation of the carotid artery and a microdialysis procedure with the probes in the hypothalamic PVN. Intra-arterial administration of cholecystokinin-8 (CCK) at the dose of 50 mg/kg was used to induce oxytocin and noradrenalin release. Leptin (10 mg/5 ml) was intracerebroventricularly injected in addition to CCK. Blood and microdialysis samples were collected at 20-min intervals for 80 min. Central administration of leptin significantly reduced both plasma oxytocin and hypothalamic noradrenalin responses to CCK at 20 min following the treatments. In conclusion, leptin may inhibit oxytocin secretion by lowering noradrenergic neurotransmission in the PVN. The modulator effect of leptin on noradrenalin release in the PVN may be related to feeding behavior.

A randomised controlled trial on melatonin and rosiglitazone for prevention of adhesion formation in a rat uterine horn model

To investigate the effectiveness of melatonin and rosiglitazone in reducing postoperative adhesion formation in a rat uterine horn model. Thirty non-pregnant female Wistar albino rats, weighing 180-220 g, were used as a model for postoperative adhesion formation. The rats were randomised into three groups after seven standard lesions were inflicted in a 2-cm segment of each uterine horn and lower abdominal sidewall using bipolar cauterisation. The rats were treated with 10 mg/kg, intraperitoneal melatonin, and 1 mg/kg per day peroral rosiglitazone. No medication was given to the control group. As much as 20 uterine horns of 10 rats were evaluated in each group. Extent, severity, and degree of the adhesions to the uterine horns and, inflammation and fibrosis scores (histopathologically) were evaluated after 2 weeks of the treatment. There was no mortality in the groups and all of the rats recovered without incident after operation. Rosiglitazone group had lower adhesion scores [median (min-max ranges)] regarding extent, severity, and degree of the adhesions [0 (0-3), 0 (0-3) and 0 (0-3), respectively], which were significantly different (P < 0.001, P < 0.05 and P < 0.01, respectively) from those of the controls [1 (0-3), 2 (0-2) and 2 (0-3), respectively]; however, there were no statistically significant differences between rosiglitazone versus melatonin groups [1 (0-4), 2 (0-3) and 1 (0-3), respectively] and melatonin versus control groups. Moreover, no significant differences were determined between groups regarding histopathologic findings. Rosiglitazone, but not melatonin, is effective in prevention of adhesion formation in a rat uterine horn model.

Effects of Ruellia praetermissa extract on ovulation, implantation, and the uterine endometrium of female rats

The effects of extracts of Ruellia praetermissa (Acanthaceae) on ovulation, implantation, uterine weight and foetal development were studied in adult rats. Female rats weighing 180 to 220 g were divided into three experimental groups. Group 1 was administered 200 mg/kg body weight of the extract at 10, 14 and 18 h respectively on proestrous rats. Vaginal smears were taken daily to monitor the oestrous cycle and ovulation. Group 2 consisted of pregnant rats, which received the same dose of the extract on days 1 - 5, 7 - 9, 9 - 17 and 1 - 17 of gestation. Gestational parameters (number of corpora Lutea, implantation sites, resorption sites and dead foetuses) were monitored. In group 3, non-pregnant mature female rats were treated with the same dose of the extracts from 1 - 17. The uterine muscle weight was recorded on days 4, 9, 15, and 18. Ovulation was partially blocked resulting in reduced number of ova in the oviduct of the treated rats (3 ± 1, 5 ± 1 and 10 ± 3 treated at 10: 00, 14: 00 and 18: 00 h respectively) compared with control (12 ± 5: p < 0.05). There was 20% increase in implantation rate in rats which received treatment for the first five days of gestation (p < 0.05). There is an increase (0.05 ± 0.002 - 0.35 ± 0.001) of the uterine weight comparable to that produced by using 3 µM 17b-estradiol (0.03 ± 0.001 - 0.35 ± 0.005). The decrease in effects on ovulation and the increase in the uterine walls are possibly due to flavaonoids (luteolin, quercetin, and apigenin). Increase in Implantation and the uterine weight are due in part by plant sterols (β-sistosterol and stigmasterol) identified in the EtOAc extracts of this plant drug. These findings provide the pharmacological basis for the traditional use of this plant for prenatal care in the North West Region of Cameroon. Key words: Ruellia praetermissa, ovulation, implantation, uterine endometrium, flavonoids, plant sterols.

Human health risk assessment of endosulfan. I: Toxicology and hazard identification

Endosulfan is persistent in the environment and toxic to wildlife. Legal mandates necessitate that a risk assessments be performed for endosulfan by the California Department of Pesticide Regulation (CDPR) and the United States Environmental Protection Agency (USEPA). This hazard identification (hazard ID) compared critical no-observed effect levels (NOEL) for acute, subchronic and chronic exposure intervals between the agencies. NOELs were discussed in light of their application to numerous exposure scenarios (occupational, general population and dietary). Only the acute oral NOELs differed between CDPR (0.7 mg/kg/day) and USEPA (1.5 mg/kg/day). Pregnant rabbits were considered by CDPR to be more responsive to low gavage doses of endosulfan than non-pregnant female or male rats in the acute study selected by USEPA. NOELs for other exposure routes and durations were similar between agencies. CDPR and USEPA concurred that a Food Quality Protection Act ( FQPA, 1996) Safety Factor is not needed after evaluating all studies including a Developmental Neurotoxicity study. The SF was reduced to 1×. NOELs generated from this hazard ID will be used to calculate the Margins of Exposure for all scenarios and subsequently the risk characterization for endosulfan.

Effects of single immobilization stress on the GABA metabolism and behavior of pregnant and nonpregnant female rats during early post-stress period

We studied the effects of a single immobilization stress on pregnant (9th or 10th day of pregnancy) and nonpregnant female rats in the early post-stress period (1 day after a stress). We analyzed the changes in behavioral responses, activity of antioxidant systems (ASs), and GABA metabolism. It was shown that control unstressed pregnant rats had a higher level of locomotor and exploratory activities and a lower level of anxiety and emotional tension as compared to nonpregnant rats. The pregnant rats were characterized by a higher activity of glutamate decarboxylase (GDC). In nonpregnant rats in the early post-stress period, the locomotor and exploratory activity and “risk behavior” increased, while anxiety decreased. These changes were not related to changes in the GABA metabolism, while the efficacy of ASs was increased. In the group of pregnant rats, the consequences of immobilization included only a significant increase in the activity of GABA transaminase (GABA-T). Thus, pregnant rats had higher stress resistance than the nonpregnant rats, according to behavioral indices and activities of systems of GABA metabolism and ASs.

Regulation of the vitamin D receptor and cornifin beta expression in vaginal epithelium of the rats through vitamin D3

The aim of the present study was to determine the respective role of 1,25-dihydroxyvitamin D3 on vaginal epithelium and 1,25-dihydroxyvitamin D3 receptor expression in ovariectomized rats and vitamin D3 treated rats. Bilateral ovariectomies were performed in 20 mature, non-pregnant Wistar female rats. All the animals were divided into 2 groups consisting of 10 rats each. Group I served as control. In group II, animals were injected intramuscularly with vitamin D3 (50, 00 IU/kg). Two weeks after the injections, vaginas of animals in group I and group II were removed removed and processed for immunohistochemistry. Epithelial differentiation, 1,25-dihydroxyvitamin D3 receptor and cornifin beta expression were investigated in vaginal epithelium of control group (ovariectomized) and vitamin D3 treated rats. Vaginal epithelial cells from vitamin D3 treated animals changed into highly- stratified keratinizing layers. 1,25-dihydroxyvitamin D3 receptor and cornifin beta as a marker of squamous differentiation were present in ovariectomized rats treated with 1,25-dihydroxyvitamin D3. In contrast, cornifin beta and 1,25-dihydroxyvitamin D3 receptor were absent in all layers of vaginal epithelium in control group. We demonstrated for the first time that 1,25-dihydroxyvitamin D3 induced proliferation of vaginal epithelium consistent with the cornifin beta expression and 1,25-dihydroxyvitamin D3 up-regulated 1,25-dihydroxyvitamin D3 receptor expression in vaginal epithelium.

Role of catecholamines in the central actions of medroxyprogesterone acetate.

The role of catecholamines in the mechanism of antiovulatory and other central effects of medroxyprogesterone acetate (MPA) has been studied in adult healthy, non-pregnant female albino rats. It has been observed that a single dose of MPA (100 mg/kg) given intramuscularly did not cause any significant change in brain catecholamine levels after 7 days of treatment. However, there was a significant reduction in brain dopamine levels after 15 days of MPA administration. This reduction in brain dopamine levels may be responsible for the anti-ovulatory activity of MPA. Certain side effects of MPA such as amenorrhoea, galactorrhoea, breast tenderness, breast tumors, inactivity and depression may also be due to decrease in brain dopamine levels.

Plasma and pituitary gonadotropins and prolactin after hysterectomy and treatment with uterine extracts in female rats. A kinetic study.

The kinetic of changes in plasma concentrations and pituitary contents of FSH, LH, prolactin after hysterectomy and treatment with steroid-free uterine extracts were studied in adult, non-pregnant female rats. The post-castration rise of plasma and pituitary FSH and plasma LH was inhibited but the plasma prolactin was elevated by hysterectomy. Steroid-free uterine extracts from previously castrated animals increased the plasma FSH, LH and prolactin concentrations in hysterectomized females 48 hours after administration. Uterine extracts from intact and oestradiol-substituted-castrated animals decreased the pituitary prolactin content 48 h after single i.p. injection. Pituitary FSH and LH contents were not affected by single dose of uterine extracts at any time which were examined. It is concluded that the uterus may play some role in the synthesis and release of pituitary gonadotropins and prolactin.

Effects of increasing ratio of progesterone in estrogen/progesterone combination on total oxidant/antioxidant status in rat uterus and plasma

The relationship between increasing ratio of progesterone in estrogen/progesterone combination and oxidative stress (OS) was investigated. Thirty non-pregnant Wistar Albino female rats were divided into five groups and bilaterally ovariectomized (Ovx) except sham group. GROUPS: Sham+0.3cc seaseme oil, Ovx+0.3cc seaseme oil, Ovx+estradiol propionate (E2) (1μg/kg), Ovx+E2+medroxyprogesterone acetate (MPA) 1mg/kg, Ovx+E2+MPA 20mg/kg. Hormones were applied for three consecutive days after 28days of ovariectomy. Their uteri and blood samples were collected and nitric oxide (NO), malondialdehyde (MDA), total oxidative status (TOS) and total antioxidant capacity (TAC) levels were determined. E2+MPA1 treatment decreased NO, MDA and TOS levels and increased TAC levels in uterus. Plasma NO levels elevated in all groups and MDA production increased due to E2 treatment when compared to ovariectomy. E2+MPA20 treatment increased TOS levels, while TAC levels decreased when compared to ovariectomy in plasma. Using E2 plus low dose progesterone may prevent pathologies resourced of OS.