High Progesterone Concentrations Research Articles

The potential perinatal origin of placentation disorders in the young primigravida

The fetus is exposed to high plasma concentrations of unbound estrogens and progesterone throughout pregnancy. However, secretory or decidual changes in the fetal uterus occur relatively infrequently before birth, suggesting a variable endometrial progesterone response at the time of birth. Arguably, partial progesterone resistance that persists into adolescent years may compromise the physiological transformation of the spiral arteries and predispose for defective placentation in the case of pregnancy. Decidualization of the endometrial stromal compartment and junctional zone myometrium precedes trophoblast invasion. It represents the first step in the process of spiral artery remodeling needed to establish effective uteroplacental blood flow by midpregnancy. The major obstetric syndromes caused by impaired placental bed spiral artery remodeling are prevalent in teenage pregnancies, including preeclampsia, fetal growth restriction, and spontaneous preterm labor. Preconditioning of the uterus in response to cyclic menstruation during adolescence may be critical to achieve full uterine responsiveness to hormonal cues. Understanding the mechanisms of functional maturation of the uterus during the early reproductive years may yield novel insights into the major obstetric syndromes.

Profile of growth hormone, FSH, LH and steroid hormones during gestationin Murrah buffalo

The study was conducted on 11 apparently healthy Murrah buffaloes, aged 8.18 ± 0.61 years and in 2nd to 6th lactation. The buffalo, exhibited estrus was served naturally and blood samples from each buffalo were collected after the service. On confirmation of pregnancy by rectal palpation, blood collection from that animal was continued at every fortnightly interval, during entire gestation, till parturition. If the inseminated buffalo expressed estrus at the next subsequent estrous cycle, it was excluded from the study. The results indicated that the average gestation length in Murrah buffaloes was 321 ± 2.65 days. The growth hormone exhibited increase with advancement in gestation. The FSH showed increasing trend from early to mid gestation, the levels were low during late gestation. The LH and estradiol exhibited increasing trend from early through late gestation. Higher concentration of progesterone was recorded during mid gestation.. Serum cortisol did not significantly differ.

Progesterone and Melanoma Cells: An Old Story Suspended between Life and Death

Melanoma is a widespread cancer with poor prognosis. Female hormones are known to be capable of influencing melanoma progression but clinical data related to pregnancy, oral contraception and hormone replacement therapy are controversial. A few reports show that in vitro progesterone (PG) affects melanoma growth in nuclear progesterone receptor (nPR)-positive and nPR-negative cells, but the experimental protocols used are quite different and the results are not univocal. Further research on this topic is thus needed especially in view of the widespread use of PG in clinical practice. In this study, we used human melanoma cells (A-375), which were cultured in vitro in the presence or absence of a wide range of PG concentrations (from 0.01 to 1000 M) in single treatment. Daily cell count, cell cycle analysis and apoptosis assay were performed. Our results show that the low PG concentrations (from 0.01 to 1.0 M) promote a significant increase of melanoma cell proliferation but this growth-stimulatory effect is not observed at 10 M PG and the higher PG concentrations (i.e. 100 and 1000 M) induce a cell density reduction which is the result of both cell cycle arrest and apoptosis. These findings confirm and extend previous observations reported in the international literature. A higher caution in the clinical use of progesterone is thus mandatory, since PG concentrations capable of stimulating melanoma cell proliferation are very close to those commonly used in a wide spectrum of physio-pathological conditions.

Progesterone elevation on the day of human chorionic gonadotropin administration is not the only factor determining outcomes of in vitro fertilization

To assess whether progesterone elevation is the only factor in determining outcomes of in vitro fertilization (IVF). Retrospective cohort study. Infertility clinic at Kaohsiung Chang Gung Memorial Hospital, Taiwan. One thousand five hundred eight women undergoing a total of 1,508 IVF cycles. None. Clinical pregnancy and live-birth rates. Patients were classified into four subgroups according to their progesterone concentration on the day of human chorionic gonadotropin (hCG) triggering. The clinical pregnancy and live-birth rates were statistically significantly associated with the age of the woman, the day of embryo transfer, the progesterone concentration on the day of hCG administration, the number of transferred embryos, and the number of top-quality embryos transferred. However, after omitting the women with the highest progesterone concentration (≥1.94 ng/mL), only four factors-patient age, day of embryo transfer, number of transferred embryos, and number of top-quality embryos transferred-were statistically significantly associated with the clinical pregnancy and live-birth rates. Progesterone concentration on the day of hCG administration is not the only factor determining the clinical pregnancy and live-birth rates. Fresh embryos from women should be frozen with extremely high progesterone concentrations. Each patient's general condition and the capacity for frozen-thawed embryo transfer should be considered before implantation.

Clinical features of progressive vacuolar hepatopathy in Scottish Terriers with and without hepatocellular carcinoma: 114 cases (1980-2013).

To characterize signalment, clinical features, clinicopathologic variables, hepatic ultrasonographic characteristics, endocrinologic profiles, treatment response, and age at death of Scottish Terriers with progressive vacuolar hepatopathy (VH) with or without hepatocellular carcinoma (HCC). Retrospective case series. 114 Scottish Terriers with progressive VH. Electronic databases from 1980 to 2013 were searched for adult (age > 1 year) Scottish Terriers with histopathologic diagnoses of diffuse glycogen-like VH. Available sections of liver specimens were histologically reevaluated to confirm diffuse VH with or without HCC; 8 dogs with HCC only had neoplastic tissue available. Physical examination, clinicopathologic, treatment, and survival data were obtained. 39 of 114 (34%) dogs with VH had HCC detected at surgery or necropsy or by abdominal ultrasonography. Histologic findings indicated that HCC was seemingly preceded by dysplastic hepatocellular foci. No significant differences were found in clinicopathologic variables or age at death between VH-affected dogs with or without HCC. Fifteen of 26 (58%) dogs with high hepatic copper concentrations had histologic features consistent with copper-associated hepatopathy. Although signs consistent with hyperadrenocorticism were observed in 40% (46/114) of dogs, definitive diagnosis was inconsistently confirmed. Assessment of adrenal sex hormone concentrations before and after ACTH administration identified high progesterone and androstenedione concentrations in 88% (22/25) and 80% (20/25) of tested dogs, respectively. Results suggested that VH in Scottish Terriers may be linked to adrenal steroidogenesis and a predisposition to HCC. In dogs with VH, frequent serum biochemical analysis and ultrasonographic surveillance for early tumor detection are recommended.

Characterization of physico-chemical properties of cervical mucus in relation to parity and conception rate in Murrah buffaloes

Cervicalmucusisaviscoelasticsecretionofconstantly secreting mucus producing cells of the endo-cervix [1] and acts as a mechanical barrier to prevent intruding organisms. It is a complex biomaterial having a vital protective function in the cervix during pregnancy. Bovine cervical mucus exists into two phases, aqueous and gel [2]. The aqueous phase contains mostly water (92-95%)with some ions andmetabolites [3]; whereas the glycoproteins (mucins) are themajor component of the gel phase [4]. Colour, appearance, pH and electrical conductivity along with other rheological properties like Spinnbarkeit value, flow elasticity, viscosity, thixotrophy, and arborisationpattern are themost important properties in relation to fertility. These properties vary with endocrinological status of reproductive cycle and directly associated with the estrogen: progesterone ratio and fertility status of dairy animals [5]. Basically two types of cervicalmucus are observed , estrogenic and gestagenic [6] which can be further divided into various subtypes. The rheological properties of cervical mucus becomesmore plentiful, watery and less viscous, during follicular phase, which facilitates the transport of spermatozoa in the female reproductive tract. However, it becomesopaque, thick, viscousandscantyduring luteal phase not favourable to sperm migration [2]. Cervical secretion becomes more copious and watery during the estrogen dominating phase of ovarian cycle while the viscosity of mucus increases under high progesterone concentration. Therefore may be used in determining the stage of estrus for fixing an optimum time of insemination in farm animals. The occurrence of crystallization is common to all types of mucus. But degree of crystallization/ arborisation pattern in cervical mucus is under the control of two ovarian hormones ., estrogen and progesterone. The phenomenon of crystallization in cervical mucus progresses under the influence of estrogen where as progesterone diminishes the formation of arborisation pattern [3]. Thus it viz.

Menstrual cycle change in thalamic glutamate decarboxylase and GABA in response to TMJ pain in rats (726.4)

Women report TMJ pain more often than men and epidemiological evidence suggests the pain response varies between men and women and over the menstrual cycle. Recent studies show TMJ responsive neurons projecting to the thalamus have different activities in male and females. Using a rat model our lab performed whole genome array screens on thalamic tissue of cycling rats. The results indicate that the transcript of both glutamate decarboxylase 1 and 2 (GAD67 and GAD65, respectively) are significantly up‐regulated in the thalamus of proestrus (high estrogen, progesterone and luteinizing hormone concentration) versus diestrus/metestrus (low estrogen, progesterone and luteinizing hormone concentration) rats. On the other hand, GABA expression (by ELISA assay) did not significantly change in the thalamic tissue during the proestrus phase. The differences in response of the enzyme and its product could be explained by the distribution of each enzyme within individual neurons. In conclusion, sex steroids could alter thalamic GABAergic signaling to effect TMJ hyperalgesia through regulation of GAD.Grant Funding Source: Supported by NIH R01 NIDCR grant: DE022129 Estrogen and TMJ Pain

Coagulation parameters do not change during luteal phase and pregnancy in cats

Changes in coagulation parameters depending on reproductive status and pregnancy have been previously reported in both human and other veterinary species. The objective of this study was to determine if different reproductive status affects coagulation parameters in queens. Blood samples from 66 queens submitted to spay surgery were obtained. A hemostatic panel including platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen concentration, and D-dimer and also progesterone concentrations were measured before surgery. According to progesterone results and embryo vesicles diameter, four groups were established: (1) nonpregnant queens with low (≤1 ng/mL) progesterone concentration (LP) (n = 33); (2) nonpregnant queens with high (≥2 ng/mL) progesterone concentration (n = 8) (HP); (3) first half of pregnancy (n = 12); and (4) second half of pregnancy (n = 13). None of the evaluated parameters showed statistically significant differences among the different groups. There was no significant linear correlation between progesterone values and coagulation parameters. In conclusion, neither the presence of the embryo nor the higher values of progesterone concentration induced statistically significant changes in the coagulation profile studied.

Versatile Action of Picomolar Gradients of Progesterone on Different Sperm Subpopulations

High step concentrations of progesterone may stimulate various sperm physiological processes, such as priming and the acrosome reaction. However, approaching the egg, spermatozoa face increasing concentrations of the hormone, as it is secreted by the cumulus cells and then passively diffuses along the cumulus matrix and beyond. In this context, several questions arise: are spermatozoa sensitive to the steroid gradients as they undergo priming and the acrosome reaction? If so, what are the functional gradual concentrations of progesterone? Do spermatozoa in different physiological states respond differentially to steroid gradients? To answer these questions, spermatozoa were confronted with progesterone gradients generated by different hormone concentrations (1 pM to 100 µM). Brief exposure to a 10 pM progesterone gradient stimulated priming for the acrosome reaction in one sperm subpopulation, and simultaneously induced the acrosome reaction in a different sperm subpopulation. This effect was not observed in non-capacitated cells or when progesterone was homogeneously distributed. The results suggest a versatile role of the gradual distribution of very low doses of progesterone, which selectively stimulate the priming and the acrosome reaction in different sperm subpopulations.

Short term dietary propylene glycol supplementation affects circulating metabolic hormones, progesterone concentrations and follicular growth in dairy heifers

This study was designed to determine the effects of dietary propylene glycol (PG; Propypact®, DIFAGRI, France) on blood metabolites, metabolic and reproductive hormones and follicular growth in 10 dairy heifers. Treatments consisted of (1) 1.1kg of sugar beet pulp (Control), (2) 150g PG (PG150) and (3) 300g PG (PG300). Each heifer received the three treatments in different randomized orders. A standard hay/concentrate diet, formulated to allow a daily liveweight gain of 900g/day, was given at 8:00 and the dietary treatments were given at 16:00 from Days 1 to 13 of the oestrous cycle following induced oestrus (Day 0). Oestrus induction treatment consisted of a subcutaneous 3mg norgestomet implant inserted for 9 days combined with GnRH treatment (i.m.) at implant insertion. Two days before implant removal, 500µg cloprostenol was administered i.m. Blood samples were collected by jugular venipuncture every 2h for 24h on Days 0 and 13 to measure plasma insulin, glucose, β-hydroxybutyrate (BHB) and urea concentrations. Blood samples were also collected to measure insulin-like growth factor-1 (IGF-1), oestradiol, progesterone concentrations on Days 2, 6, 9 and 12 and AMH (Anti-Müllerian hormone) on Days 0, 2, 6, 9 and 12. On Days 2, 6, 9 and 12 ovarian follicular growth was evaluated; the total number of follicles and their diameters were recorded and classed (2–3mm, 4–7mm, and >8mm). Results were analysed by repeated-measures ANOVA. There were no treatment, day and interaction effects on average urea concentrations while there were some differences between Days 0 and 13 for insulin, glucose and BHB. Insulin and glucose concentrations were higher on Day 13 compared to Day 0 and the opposite was observed for BHB. There were treatment, time and interaction effects on glucose and BHB concentrations measured over 24h on Day 13; glucose concentrations were higher (P<0.05) at 4:00, 8:00, 12:00, 16:00 and 20:00h, whereas BHB concentrations were lower (P<0.05) at 20:00 and 22:00h in the PG300 group compared to the control and PG150 groups. There were treatment, day and interaction effects on IGF-1 and progesterone concentrations, and the number of small follicles. PG150 resulted in higher progesterone concentrations on Days 9 and 12, and more small follicles on Day 2 compared to Control. AMH concentrations were unaffected by day of oestrous cycle and dietary treatment. However a negative correlation was observed between pre-PG distribution insulin and AMH (r=−0.47, P<0.05). These results indicate that short-term dietary PG supplementation affects circulating concentrations of metabolites and metabolic hormones, increases progesterone concentrations and the number of small follicles. Propylene glycol supplementation may be effective in improving oocyte production when combined with hormonal treatments to stimulate follicular growth for superovulation or ovum-pick up.

Effect of the first GnRH and two doses of PGF2α in a 5-day progesterone-based CO-Synch protocol on heifer pregnancy

The objectives were (1) to determine the effects of gonadorelin hydrochloride (GnRH) injection at controlled internal drug release (CIDR) insertion on Day 0 and the number of PGF2α doses at CIDR removal on Day 5 in a 5-day CO-Synch + CIDR program on pregnancy rate (PR) to artificial insemination (AI) in heifers; (2) to examine how the effect of systemic concentration of progesterone and size of follicles influenced treatment outcome. Angus cross beef heifers (n = 1018) at eight locations and Holstein dairy heifers (n = 1137) at 15 locations were included in this study. On Day 0, heifers were body condition scored (BCS), and received a CIDR. Within farms, heifers were randomly divided into two groups: at the time of CIDR insertion, the GnRH group received 100 μg of GnRH and No-GnRH group received none. On Day 5, all heifers received 25 mg of PGF2α at the time of CIDR insert removal. The GnRH and No-GnRH groups were further divided into 1PGF and 2PGF groups. The heifers in 2PGF group received a second dose of PGF2α 6 hours after the administration of the first dose. Beef heifers underwent AI at 56 hours and dairy heifers at 72 hours after CIDR removal and received 100 μg of GnRH at the time of AI. Pregnancy was determined approximately at 35 and/or 70 days after AI. Controlling for herd effect (P < 0.06), the treatments had significant effect on AI pregnancy in beef heifers (P = 0.03). The AI-PRs were 50.3%, 50.2%, 59.7%, and 58.3% for No-GnRH + PGF + GnRH, No-GnRH + 2PGF + GnRH, GnRH + PGF + GnRH, and GnRH + 2PGF + GnRH groups, respectively. The AI-PRs were ranged from 50% to 62.4% between herds. Controlling for herd effects (P < 0.01) and for BCS (P < 0.05), the AI pregnancy was not different among the treatment groups in dairy heifers (P > 0.05). The AI-PRs were 51.2%, 51.9%, 53.9%, and 54.5% for No-GnRH + PGF + GnRH, No-GnRH + 2PGF + GnRH, GnRH + PGF + GnRH, and GnRH + 2PGF + GnRH groups, respectively. The AI-PR varied among locations from 48.3% to 75.0%. The AI-PR was 43.5%, 50.4%, and 64.2% for 2.5 or less, 2.75 to 3.5, and greater than 3.5 BCS categories. Numerically higher AI-PRs were observed in beef and dairy heifers that exhibited high progesterone concentrations at the time of CIDR insertion (>1 ng/mL, with a CL). In addition, numerically higher AI-PRs were also observed in heifers receiving CIDR + GnRH with both high and low progesterone concentration (<1 ng/mL) initially compared with heifers receiving a CIDR only with low progesterone. In dairy heifers, there were no differences in the pregnancy loss between 35 and 70 days post-AI among the treatment groups (P > 0.1). In conclusion, GnRH administration at the time of CIDR insertion is advantageous in beef heifers, but not in dairy heifers, to improve AI-PR in the 5-day CIDR + CO-Synch protocol. In addition, in this study, both dairy heifers that received either one or two PGF2α doses at CIDR removal resulted in similar AI-PR in this study regardless of whether they received GnRH at CIDR insertion.

Synchronisation of ovulation for management of reproduction in dairy cows

Important developments have occurred in the last two decades, since the advent of the Ovsynch protocol, on the understanding and use of synchronisation programmes for management of reproduction in dairy herds. This better understanding of oestrus cycle control associated with suboptimal reproductive performance in dairy herds has led dairy producers to quickly adopt timed artificial insemination (AI) protocols. Recent surveys have documented that fixed-time AI has become an important component of management of reproduction in high-producing herds. Furthermore, timed AI protocols have also demonstrated benefits in pasture-based milk production systems because of the ability to increase insemination rate. In general, successful use of the Ovsynch protocol requires some fundamental physiological principles to be respected, including: induction of ovulation to synchronise follicle growth in the first 2 days of the programme such that a young antral follicle is recruited; maintenance of high concentrations of progesterone during the development of the ovulatory follicle, but also effectively lyse the corpus luteum to result in very low concentration of progesterone at AI; and having a healthy pre-ovulatory follicle of moderate diameter that is highly oestrogenic and responsive to gonadotropins to synchronously ovulate 12 to 18 h after insemination. Current methods oestrous and ovulation synchronisation are still not optimal and future improvements will likely require new technologies for hormone formulation and delivery such that additional interventions are minimised to maintain acceptance by producers.

The effect of multiple PGF treatment during early dioestrus on luteolysis and pregnancy rate in the mare

s / Journal of Equine Veterinary Science 34 (2014) 160 160 mares treated with multiple PGF doses and mares treated singly 112 h post-ovulation (n 1⁄4 89) was 17.2 0.6 and 14.9 0.9 (P 1⁄4 0.03), respectively. Overall the IOI of all mares classified as having no clinical response, partial or full luteolysis was 21.6 0.5, 15.08 0.4 and 15.15 0.2, respectively. The pregnancy rate of mares treated with PGF every 8 h from 16 to 112 h was 57% (8/14). Fig. 1. Effect of CL age on the luteolytic response to a single treatment of PGF. Mares were treated singly with 37.5 mg of d-cloprostenol at ascending intervals of 8 h from 72 to 144 h post-ovulation. The number of cycles in each time point is shown in brackets. Different letters (a, b, c, d and e; x, y, z, w and u) indicate significant difference (P < 0.05) in the percentage of cycles with full and partial luteolysis. Fig. 2. Effect of number of treatments and age of CL at first treatment on the luteolytic response to a multiple treatments with PGF. Mares were treated repeatedly with 37.5 m of d-cloprostenol every 8 h from 16 to 112 h postovulation. The number of cycles in each group (CL age at first PGF treatment) is shown in brackets. Different letters (a, b) indicate significant difference (P < 0.05) in the percentage of mares with full luteolysis. An asterisk (*) shows significant difference (P < 0.05 *; P < 0.01 **) in the % of mares with full luteolysis for each group compared to the reference value of mares treated singly 112 h post-ovulation (discontinued line). The percentage of partial luteolysis did not differ significantly amongst different time points. 4. Discussion Surprisingly, the administration of 4 to 13 treatments of PGF every 8 h during early dioestrus resulted in a significantly lower percentage of mares with full luteolysis compared with previous studies [3] or when the mares were treated with a single administration of PGF at the same oldest CL age. Perhaps, the increased frequency (every 8 h) and duration of treatment of the current study accounted for this poor luteolytic response, and somehow interfered with the physiological mechanism of spontaneous luteolysis involving PGF receptors. Some evidence to support this hypothesis is the increase in the percentage of mares with prolonged dioestrus after multiple PGF treatment. In a similar line, frequent administration of oxytocin (another hormone involved in the physiology of luteolysis) during dioestrus inhibited luteolysis [4]. The length of the IOI in mares with partial and full luteolysis was not different in the current study. This was similar to results of previous studies [2] in which the IOI of mares treated with PGF on day 10 or 3 were similar despite having partial luteolysis and higher concentration of progesterone. This shows the accuracy of differentiating between partial and full luteolysis based on ultrasound parameters. The longer IOI of mares treated with multiple doses compared with singletreated mares accounts for a greater percentage of mares with no response to treatment. The acceptable PR of mares inseminated and treated repeatedly with PGF during the subsequent dioestrus reveals the ability of mares to maintain a viable pregnancy with reduced concentrations of progesterone during early embryo development. Similarly, treatment with PGF to mares 24 to 72 h after ovulation did not decrease PR [5].However, the number of mares in the latter study was too low to draw strong conclusions. On the other hand, some of these mares had dioestrus ovulations which would have contributed to increase the concentration of progesterone.

Effect of a GNRH antagonist on follicular development, luteal function and fetal viability in mares carrying equine or mule pregnancies

s / Journal of Equine Veterinary Science 34 (2014) 203 203 follicle that ovulated within the first days of antarelix administration. As a result of the lack of supplementary CLs, the mares with mule pregnancy treated with antarelix had lower progesterone concentrations than non-treatedmares with the same type of pregnancy. In contrast, antarelix treatment in mares impregnated by horses (LH +eCG) resulted in the development of several large follicles that in most cases produced low estradiol concentrations, did not ovulate and developed into large accessory CL that produced higher concentrations of progesterone than those present in non-treated mares with equine pregnancies. There was a large incidence of abortions in mares impregnated with donkey semen that were treated with antarelix, while no abortions occurred in any other group (Table 1). The concentrations of eCG in the three LH eCG mares that maintained their pregnancy were higher than the average for normal mule pregnancies, and this allowed them, in spite of their LH-suppressed status, to maintain progesterone concentrations similar to those present in non-treated mule pregnancies. In contrast, only one of the five LH eCG mares that aborted had detectable concen-

121 EXPRESSION OF STEROID RECEPTORS IN THE CUMULUS - OOCYTE COMPLEX AROUND OVULATION IN THE BITCH

In the bitch, oocytes are ovulated at an immature stage (prophase I) and resume meiosis in the oviduct, 3 to 4 days after ovulation while they are still surrounded by 2 to 3 layers of cumulus cells. Canine cumulus-oocyte complexes (COC) are exposed to high and changing plasma concentrations of 17β-oestradiol (E2) and progesterone (P4) during the periovulatory period. In order to explore whether oocyte maturation may be regulated by steroids in this species, the expression of E2 (ERα, ERβ) and P4 (nuclear: PR; membrane: PGRMC1, PGRMC2, mPRα, mPRβ, mPRγ) receptors was studied in COC at precise times around ovulation. Ovaries were collected from Beagle bitches during anestrus (n = 4), after the beginning of proestrus, and before the LH peak (Pre-LH, n = 7), after the LH peak and before ovulation (Pre-ov, n = 8), and at Day 1 (n = 11) and Day 4 (n = 8) post-ovulation. Anoestrus COC were recovered from follicles smaller than 1 mm in diameter. The COC at the Pre-LH and Pre-ov stages were aspirated from preovulatory follicles (4.5–6 mm in diameter). Such follicular COC were partially denuded to leave the 2 to 3 innermost cumulus layers firmly attached to the zona pellucida. Post-ovulatory COC, naturally surrounded by 2 to 3 cumulus layers, were recovered by oviductal flushing. Total RNA was extracted from 3 batches of 10 COC per stage, then reverse transcribed. The expression of steroid receptors was assessed in duplicate by qPCR (LightCycler® 480, Roche Diagnostics) using the relative standard curve method and normalized by the geometric mean value of the two most stable reference genes (BGLR and RPS5; NormFinder software) chosen among four genes previously tested. Relative amounts of mRNA levels were compared between stages by ANOVA followed, when necessary, by a Tukey test. The ERα and ERβ expression did not vary significantly with the stage. In contrast, a significant variation between stages in nuclear and 4 membrane P4 receptor expression was observed (P &lt; 0.0001 for PR; P &lt; 0.001 for PGRMC1 and mPRβ; P &lt; 0.05 for PGRMC2 and mPRγ). The PR mRNA levels were significantly higher at Pre-ov than at any other stage. PGRMC1 expression was significantly higher at Pre-ov and Day 4 compared with anestrus and Pre-LH, and was at an intermediate level at Day 1. The expression of PGRMC2, mPRβ, and mPRγ remained low from anestrus to Day 1 and increased significantly at Day 4. Lastly, mRNA levels of mPRα were below the detection limit at all stages. This is the first report of steroid receptor expression in canine COC at precise times around ovulation. The stage-specific variation in expression of nuclear and of several membrane P4 receptors around ovulation suggests a role for P4 in canine oocyte maturation. The exact localisation of these receptors in cumulus cells, oocytes, or both remains to be determined.

Effect of progesterone concentrations, follicle diameter, timing of artificial insemination, and ovulatory stimulus on pregnancy rate to synchronized artificial insemination in postpubertal Nellore heifers

Two experiments were designed to evaluate the effects of treatments with low versus high serum progesterone (P4) concentrations on factors associated with pregnancy success in postpubertal Nellore heifers submitted to either conventional or fixed timed artificial insemination (FTAI). Heifers were synchronized with a new controlled internal drug release device (CIDR; 1.9 g of P4 [CIDR1]) or a CIDR previously used for 18 days (CIDR3) plus 2 mg of estradiol (E2) benzoate on Day 0 and 12.5 mg of prostaglandin F2α on Day 7. In experiment 1 (n = 723), CIDR were removed on Day 7 or 9 and heifers were inseminated after estrus detection. In experiment 2 (n = 1083), CIDR were all removed on Day 9 and FTAI was performed either 48 hours later in heifers that received E2 cypionate (ECP) on Day 9 (0.5 mg; E48) or 54 or 72 hours later in conjunction with administration of GnRH (100 μg; G54 or G72). Synchronization with CIDR1 resulted in greater serum P4 concentrations and smaller follicle diameters on Days 7 and 9 in both experiments. In experiment 1, treatment with CIDR for 9 days decreased the interval from CIDR removal to estrus (Day 7, 3.76 ± 0.08 days vs. Day 9, 2.90 ± 0.07; P < 0.01) and improved conception (Day 7, 57.1% vs. Day 9, 65.8%; P = 0.05) and pregnancy rates (Day 7, 37.6% vs. Day 9, 45.3%; P = 0.04). In experiment 2, treatment with ECP improved (P < 0.01) the proportion of heifers in estrus (E48, 40.9%a; G54, 17.1%c; and G72, 32.0%b), but the pregnancy rate was not affected (P = 0.64) by treatments (E48, 38.8%; G54, 35.5%; G72, 37.5%). Synchronization with CIDR3 increased follicle diameter at FTAI (CIDR1, 11.07 ± 0.10 vs. CIDR3, 11.61 ± 0.10 mm; P < 0.01), ovulation rate (CIDR1, 82.8% vs. CIDR3, 88.0%; P < 0.01) and did not affect conception (CIDR1, 42.2 vs. CIDR3, 45.1%; P = 0.38) or pregnancy rates (CIDR1, 34.7 vs. CIDR3, 39.4%; P = 0.11). In conclusion, length of treatment with P4 affected the fertility of heifers bred based on estrus detection. When the heifers were submitted to FTAI protocol, follicle diameter at FTAI (≤10.7 mm, 23.6%; 10.8–15.7 mm, 51.5%; ≥15.8 mm, 30.0%; P < 0.01) was the main factor that affected conception and pregnancy rates.

OVARIAN RESPONSE OF DAIRY COWS TO PROGESTERONE COMBINED ON

The objective of this study was to evaluate the response of ovaries in estrus synchronizationprotocol using GnRH-PGF2α based protocol combined progestin in a herd with tie-stall housing system.A total of 20 Holstein Friesian cows at different stages of estrus cycle in a dairy herd were enrolled inthe present study. The cows were randomly allocated into two treatment groups; with and without CIDR(Controlled internal drug release) insertion. All cows received 100 μg of GnRH I.M. at the beginning ofthe treatment (d 0) without regard to the stages of the estrus cycle followed by 25 mg PGF2α IM 7dayslater. Cows in CIDR group were inserted CIDR into the vagina at the time of GnRH administration andwere removed on the day of PGF2α administration. estrus signs were checked twice daily starting onday-2 after initiation of the protocol, except cows in CIDR group the estrus signs were checked startingon day-8 of the protocol. The animals showing estrus signs were noted. Blood samples were collectedfrom all animals on the days of GnRH and PGF2α treatments and on day-10 after initiation of protocolfor progesterone concentration. The results of this study showed that 30% animals in cows withoutCIDR insertion showed estrus signs prior to PGF2α injection. Involving CIDR to synchronized estruswith GnRH-PGF2α based protocol avoided the occurrence of premature estrus and maintained highprogesterone concentration on the day of PGF2α administration. It is concluded that ovarian responseafter involving CIDR in the protocol for estrus synchronization especially using combination of GnRHand PGF2α were much effective to synchronize the initiation of estrus in dairy cows. Likewise, the useof progesterone avoided premature estrus.

A case of canine bilateral ovary granulosa cell tumor and mammary complex carcinoma

An 11-year-old poodle bitch was presented for investigation of multicentric mammary masses. Abdominal sonography and radiography demonstrated abnormal enlargement of uterus and ovaries. Blood analysis revealed high progesterone concentration. The ovariohysterectomy and mastectomy were performed. Histopathologically, the mammary masses revealed complex carcinoma-tubulopapillary carcinoma with papillary pattern and tubule pattern. In the uterus, cystic endometrial hyperplasia was observed. Scattered inflammatory cells were observed in the endometrial stroma and mucinous material was protruded from endometrial surface. Also, in the ovaries, bilateral ovary granulosa cell tumor was detected. The bitch made a complete recovery following the ovariohysterectomy and mastectomy. This case was a very rare multiple tumor occurrence with bilateral ovary granulosa cell tumor and mammary complex carcinoma. High progesterone concentration was characterized clinically in the bitch.

Short Communication: Relations between peripartum concentrations of prolactin and progesterone in sows and piglet growth in early lactation

Quesnel, H., Ramaekers, P., van Hees, H. and Farmer, C. 2013. Short Communication: Relations between peripartum concentrations of prolactin and progesterone in sows and piglet growth in early lactation. Can. J. Anim. Sci. 93: 109–112. Postpartum hypogalactia has been suggested to be related to an impaired secretion of prolactin or to elevated concentrations of progesterone around farrowing. In the current study, peripartum circulating concentrations of prolactin and progesterone were determined in 50 multiparous sows (parities 1 to 5) and related to the Na K−1 ratio and lactose in colostrum and to piglet growth in early lactation. An effect of parity (P&lt;0.001) was observed for prolactin, with sows from parity 1 having lower concentrations than sows from parities 2, 3, 4 and 5, and sows from parities 4 and 5 having the greatest concentrations. Piglet growth from day 1 to day 5 was negatively correlated with progesterone concentrations in sows on day 1 (r=−0.36, P=0.01). The present study supports the hypothesis of a negative impact of high concentrations of progesterone after farrowing on early growth of piglets and also shows a clear effect of sow parity on the peripartum concentrations of prolactin suggesting that younger sows are more vulnerable to reduced milk yield due to lower prolactin concentrations.

Determination of minimum effective doses of luteinizing hormone and human chorionic gonadotropin for intrafollicular treatment to induce ovulation in dairy heifers

The aim of this study was to determine the minimum effective intrafollicular doses of luteinizing hormone and human chorionic gonadotropin in order to induce ovulation in cycling dairy heifers that have not yet been adequately established. Application of 10, 5, 1, 0.5, 0.1, 0.01 and 0.001 µg luteinizing hormone as well as 10, 1, 0.1, 0.01 and 0.001 international units (IU) of human chorionic gonadotropin in dominant follicles was performed on day 7 of the oestrous cycle. Control animals were given luteinizing hormone (12.5 mg and 25 mg) or human chorionic gonadotropin (2000 IU) intravenously. Accessory corpus luteum on day 14 of the oestrous cycle was considered as an evidence of ovulation. Ovulation was observed in 2 out of 3 heifers in each treatment group (n = 3) after administration of 10–0.1 µg luteinizing hormone (except for 0.5 µg – ovulation in 3 of 3 heifers), in all heifers after administration of 10–0.01 IU human chorionic gonadotropin as well as in all control heifers. Administration of 0.01 µg and 0.001 µg luteinizing hormone as well as of 0.001 IU human chorionic gonadotropin did not result in ovulation. Higher progesterone concentration on day 14 vs. day 7 of the oestrous cycle was found after all treatments. Nevertheless, the differences were significant (P &lt; 0.05) only after intrafollicular treatments with 5, 1 and 0.001 µg luteinizing hormone as well as 10, 1 and 0.01 IU human chorionic gonadotropin. In conclusion, minimum efficient doses for intrafollicular treatment of the dominant follicles in cycling heifers capable of inducing ovulation were 0.1 µg of luteinizing hormone and 0.01 IU of human chorionic gonadotropin. This is the first study describing the intrafollicular luteinizing hormone administration in cycling dairy heifers.