LH Peak Research Articles

153 DETECTING PRE-OVULATORY LUTEINIZING HORMONE PEAKS IN ORDER TO OPTIMIZE THE RATIO OF VIABLE EMBRYOS USING PREDI′BOV®, A NEW ON-FARM OVULATION TEST

The LH peak in cattle is the most precise event for predicting ovulation beginning 24 h later, and thus, AI time. Previous studies demonstrated that embryo production was improved when AI was conducted 12 h before ovulation; that is, 12 h after LH peak. This study aimed to evaluate the benefit of LH peak monitoring with Predi′Bov® (ReproPharm®, Nouzilly, France) following superstimulation in order to optimize numbers of viable embryos (VE). Predi′Bov® is a rapid (40 min) and easy to use on-farm test allowing LH peak detection from a few drops of blood. The test was also used to estimate the variability in the time of the LH peak and onset of oestrus. This study was conducted by the embryo transfer teams of 3 French cooperatives, in collaboration with UNCEIA. Forty heifers in stations (Creavia, Midatest) and 23 cows on farms (GEN′Iatest) were superstimulated by 8 injections IM of Stimufol® or Pluset® (FSH1 to FSH8) over 4 days in 2011–2012. Donor station heifers were treated twice in a Latin square design with a reference protocol where AI was conducted 12 and 24 h after onset of oestrus, and in an experimental protocol where AI was conducted 12 and 24 h after a positive Predi′Bov® test. Semen of different sires was used for both protocols. The Predi′Bov® test was carried out on 3 blood samples (BS1,2,3) collected every 6 h beginning at FSH7 in stations and FSH8 on farms to detect the earliest LH peaks. To determine late LH peaks, Predi′Bov® test was carried out on BS4 collected 24 h after FSH8. Univariate statistical analysis was performed to look at the relationship between qualitative (chi-square) and quantitative (t-test) variables. The difference was considered significant when P < 0.05. The Predi′Bov® test showed that 37.5% (15/40) of LH peaks occurred during the last day of FSH treatment (BS1 or BS2) in stations and 26.1% (6/23) at BS1 on farms. At Creavia station (n = 24), the LH peak was detected anytime from 24 h before to 9 h after the onset of oestrus. In stations, the VE percentage did not differ whether AI was done following oestrus or LH peak detection (63.1% and 61.8% in reference and experimental protocols, respectively). In stations, the VE percentage from 9 females with an LH peak detected at FSH7 (BS1; 41%) in the reference protocol did not differ from the experimental protocol (50%). On farms, the VE percentage was numerically higher but not significant in the experimental protocol (65.4%, n = 16) compared to the reference protocol (47.2%, n = 7). Further investigations are needed, taking into account the effect of collection rank, sire, and female effects, to confirm the trends shown by these results. In conclusion, Predi′Bov® can be used as easily on farms as in stations. Its use allows the detection of animals that have early or late LH peaks, which in turn provides the opportunity of carrying out AI at the optimal time for such females.

1 CUMULUS CELLS PROTECT OOCYTES AGAINST POTENTIAL LIPOTOXICITY FROM ELEVATED FREE FATTY ACID CONCENTRATIONS IN FOLLICULAR FLUID

Metabolic conditions characterized by elevated free fatty acid levels in the blood are often associated with reduced fertility performance. Increased concentrations of saturated free fatty acids can induce lipotoxicity in cumulus–oocyte-complexes in vitro, while unsaturated fatty acids like oleic acid are mostly harmless and able to counteract the impact of saturated fatty acids (Aardema et al. 2011 Biol. Reprod. 85, 62–69). This study investigates the impact of elevated free fatty acids in the blood on the follicular fluid and the lipid of cumulus and oocytes derived from these follicles. Furthermore, in vitro maturing oocytes were exposed to free fatty acid concentrations measured in follicles of control and metabolically stressed animals from this study to determine the impact on oocyte developmental competence. Cyclic heifers (n = 12) were synchronized (7 days CIDR®) and superstimulated from Day 10 of the synchronized cycle [4 days of Folltropin-V® (Bioniche Animal Health Inc., Belleville, ON, Canada) in decreasing doses; in total 200 mg]. Heifers received ad libitum grass silage, apart from the experimental group (n = 6), which was metabolically stressed during the period of superstimulation. Ovaries were collected by ovariectomy at final maturation, 22 h after the induced LH peak. Follicular fluids and cumulus–oocyte complexes (COC) were collected from follicles of ≥8 mm. To determine the free fatty acid and lipid composition, blood, follicular fluid, cumulus cells, and oocytes were analyzed with mass spectrometry. The COC (4 runs, 400 per group) derived from slaughterhouse ovaries were in vitro matured in a standard medium without or with the dominating free fatty acids, saturated palmitic and stearic and unsaturated oleic acid, in concentrations measured in follicular fluid of control (80, 70, and 100 µM) and experimental heifers (150, 100, and 200 µM) and fertilized and cultured until the blastocyst stage. Culture data were analyzed by one-way ANOVA and lipid data by two-sample t-test (P ≤ 0.05 considered significant). Procedures were approved by the Institutional Animal Care and Use Committee. Metabolic stress resulted in elevated free fatty acid levels in blood (from 430 ± 70 to 1048 ± 190 µM) and follicular fluid (from 357 ± 72 to 670 ± 133 µM), with relatively high oleic acid concentrations in follicular fluid (+10%). The increased levels of free fatty acids in follicular fluid resulted in a massive increase of fatty acids in the cumulus cells, but oocytes did only show marginal changes. In line with this, maturation in the presence of elevated palmitic, stearic, and oleic acid did not impair oocyte developmental competence and resulted in comparable blastocyst rates for the standard medium and the free fatty acid control and metabolic stress medium (31 ± 8.7, 34 ± 7.8, and 28 ± 1.7%). Thus, cumulus cells appear to protect oocytes against potential lipotoxicity from elevated free fatty acid concentrations by the accumulation of these fatty acids. This work was funded by Pfizer Animal Health.

Folliculogenesis, Ovulation and Endocrine Control of Oocytes and Embryos in the Dog

Reproductive physiology in dogs is quite unusual compared with that in other mammalian species. The peculiarities include the presence of numerous polyoocyte follicles, the ovulation of an immature oocyte (GV stage, non-fertilizable) and a peri-ovulatory period during which concentrations of circulating progesterone are particularly high. The aim of this review is to examine the unusual aspects of the reproductive physiology of dogs and how this relates to the clinical biology of this species.

Analysis of a family affected with familial male-limited precocious puberty due to a Ala568Val mutation in LHCGR gene

Familial male-limited precocious puberty (FMPP) is due to constitutive activation of a mutant luteinizing hormone/choriogonadotropin receptor (LH/CGR) leading to elevated testosterone synthesis in testicular Leydig cells. In the present study, we have analyzed the LHCGR gene for members of a Chinese FMPP family. Physical examinations have included assessment of penile length, testicular volume and pubic hair. Bone age assessment, levels of testosterone and gonadotropin-releasing hormone (GnRH) stimulations tests were measured. DNA was extracted from blood samples of the proband and his parents using an QIAGEN Blood DNA Mini Kit. The 11 exons of LHCGR gene were amplified using an AmpliTaq PCR system, and the PCR products were sequenced using an ABI3130xl Genetic Analyzer. The affected boy was 3 year and 1 month old and showed typical clinical manifestation of peripheral precocious puberty. His height was 116.8cm (+5.1s) and Tanner stages were PH 2. Testicular volume was 8 mL bilaterally, penile was 8.5 cm × 2.5 cm. Basal testosterone was 2310 ng/L and bone age was 9 years. GnRH stimulation test revealed a prepubertal response to gonadotropin. The peak of LH was 2.66 IU/L, and the peak of FSH was 1.03 IU/L. Upon sequencing exon 11 of the LHCGR, a heterozygous point mutation of nucleotide 1703 from C to T was detected, which resulted in an amino acid transition from Ala (GCC) to Val (GTC) at position 568. Thus the mutation of LHCGR gene was confirmed to be constitutively active. After treating with aromatase inhibitors for half a year, the patient showed an increase in bone age and height by half a year and 4 cm, respectively. The same point mutation was detected in the patient's father, but did not have any influence on his puberty development. A novel point mutation of the LHCGR gene has been identified in a family affected with FMPP. The c.1703C>T mutant LHCGR was confirmed to be constitutively active, which has led to maturation and proliferation of Leydig cells. The variable phenotype within the family suggested variable expressivity of the disease.

Clinical Evaluation of Deslorelin to Induce Oestrus, Ovulation and Pregnancy in the Bitch

The aim of this study was to evaluate the practical use of Deslorelin in a clinical setting to induce oestrus and ovulation and to assess pregnancy rates. Sixteen anoestrus bitches that were brought into the clinic were implanted subcutaneously in the ventral abdomen with Deslorelin. Implants were removed after ovulation was assumed to have occurred. All bitches came into oestrus and 13 ovulated. 11 of 16 bitches became pregnant (68.8%) and all continued to term. Average litter size was 7.6 puppies. On average, the implant was in place for 13.8 days.

Endocrine and Molecular Control of Luteal and Placental Function in Dogs: A Review

In the domestic dog (Canis familiaris), the corpus luteum (CL) is the only source of progesterone (P4) in non-pregnant and pregnant animals. The progesterone secretion profiles are almost identical in both conditions until the last third of the luteal phase when the gradual P4 decline turns into a steep drop in pregnant bitches, indicating the onset of parturition. Consequently, the length of the CL-phase in non-pregnant dogs exceeds the luteal lifespan in pregnant animals. The canine CL-function is regulated by many species-specific regulatory mechanisms, the most intriguing of which is the reported independence of gonadotropic support during the first third of dioestrus. Recently, PGE2 has been proposed as one of the most important luteotropic factors acting locally during this time, but afterwards prolactin (PRL) appears to be the main luteotropic factor. Luteal regression/luteolysis occurs, however, in spite of an increased gonadotropic support. Lately, by demonstrating the expression of PRL-receptor (PRLr), a new insight into possible regulatory mechanisms has indicated that the supply of P4 could be controlled upstream of the steroidogenic machinery at the level of PRLr expression and/or function, subsequently leading to the functional suppression of the steroidogenic machinery. An endogenous source of a luteolytic agent is apparently lacking, implicating the luteal regression in non-pregnant bitches as a passive, degenerative process even if the PGF2α-receptor is constitutively expressed in canine CL. This is in contrast to pregnant dogs in which prepartum luteolysis seems to be an active process of CL destruction by PGF2α of utero/placental origin targeting the luteal PGF2α-receptor.

Hypertension During Therapy with Triptorelin in a Girl with Precocious Puberty

To the Editor: GnRH-receptor agonists are used for treatment of central precocious puberty (CPP) and relative safety and tolerability in children are reported [1]. In experimental studies, hypertensive crisis during treatment with triptorelin is described and attributed to hypoestrogenism [2]. Postmenopause is associated with increased incidence of hypertension; estrogen low levels have important effects on venous system that reverse in animal model by hormone replacement therapy [3]. We report a “suggested” association between hypertension and triptorelin therapy in a girl with CPP. A 5-y-old girl presented with breast enlargement (Tanner B2), without any other sign of sexual maturation and with prepubertal hormonal status. At the age of 7y, she showed progressive breast development (Tanner B3), bone age advancement (SDS-BA 2.5), elevated height velocity (SDS-v 3.17). Blood pressure (BP) was 105/70 mmHg (50th centile for systolic and 90th centile for diastolic [4]). Endocrine examination revealed GnRH-stimulated serum LH peak 14.7 mIU/ml and β-estradiol level 25.6 pg/ml. Magnetic Resonance Imaging showed a 1.8×1.0×1.2 cm pineal cyst, with homogeneous content and slightly thickened wall with focal irregularity. Alpha-feto-protein and human-chorionic-gonadotropin levels were negative. Therapy with Triptorelin 3.75 mg/4 wk was started. No neurosurgical intervention was planned immediately. At the age of 10y–8 mo, we noted asymptomatic hypertension (150/110 mmHg, >99th centile [4]). Ambulatory BP monitoring confirmed severe hypertension, with 24-h mean systolic and diastolic BP>3SD [5]. Transthoracic echocardiographic evaluation showed concentric hypertrophy of the left ventricle, with increased thickness of interventricular septum and posterior wall. Renovascular and renal parenchymal diseases, endocrine causes of hypertension, coartaction of aorta were excluded. We discontinued GnRH-analog and started anti-hypertensive therapy (ramipril 5mg/die and nifedipine retard 40 mg/die). Progressively, the girl showed normalization of BP values and reduction of left ventricle wall thickness. Anti-hypertensive treatment was modified during follow-up; nifedipine retard and ramipril were stopped after 4 and 8 mo, respectively. At the age of 11y-8-mo the girl had menarche. Normal BP values persist. Considering the normotensive condition at the start therapy, the reversibility of hypertension and cardiac hypertrophy after discontinuation of triptorelin and the persistence of V. Calcaterra :D. Larizza Department of Internal Medicine, University of Pavia and Department of Pediatrics, IRCCS Policlinico S. Matteo Foundation, Pavia, Italy

An evaluation of B-mode and color Doppler ultrasonography for detecting periovulatory events in the bitch

When determining optimal breeding time in the bitch, specific periovulatory events must be identified. The main objectives were to relate ultrasonographic changes in ovarian blood flow, follicle/corpora lutea count and echotexture to periovulatory events, and to assess the efficacy of each for identifying these events. Twelve Beagle (N = 3), Beagle-cross (N = 2) and hound-cross (N = 7) bitches (body weight range, 7.5–27.5 kg) were examined daily from the onset of proestrus to approximately 4 days post-LH peak. Follicle and corpora lutea count and echotexture analyses were performed using B-mode ultrasound and ovarian blood flow analysis was performed using color Doppler ultrasound. Serum LH concentrations were analyzed by validated RIA. There was an increase (P < 0.05) in ovarian blood flow from the day of the preovulatory LH peak (605 pixels; confidence interval, 397–856), to 1 day after this peak (1092 pixels; confidence interval, 724–1535), enabling detection of the preovulatory LH peak. There were no significant changes in follicle/corpora lutea echotexture relative to days from the preovulatory LH peak. There were significant decreases in follicle/corpora lutea number between Days −1 and 3; Days −1 and 4; and Days 0 and 3, relative to the preovulatory LH peak. We concluded that color Doppler ultrasound performed once daily was more accurate in identifying the preovulatory LH peak than B-mode ultrasound and enabled prospective determination of ovulation.

Effect of Estradiol and Progesterone on Metabolic Biomarkers in Healthy Bitches

The aim of this study was to evaluate the possible association between hormonal changes that occur during oestrus and biomarkers related with glucose metabolism (glucose and insulin), lipid metabolism (lipidic profile and BChE) and adipokines (adiponectin and ghrelin) in healthy bitches. For this purpose, we measured these analytes in serum of bitches, at two times: before (T1) and after (T2) the LH peak that were established according to progesterone concentrations. Increased levels of total cholesterol (p<0.01), high density lipoprotein cholesterol (HDL-C) (p<0.01), low density lipoprotein cholesterol (LDL-C) (p<0.01), adiponectin (p<0.01) and ghrelin (p<0.05) were observed at T2 in comparison with T1. No statistically significant changes were observed in serum glucose, insulin, homoeostasis model assessment for insulin sensitivity (HOMA), triglycerides and BChE. When all data of T1 and T2 were pooled, serum adiponectin showed positive correlation with progesterone (r=0.353; p=0.022) and HDL-C (r=0.307; p=0.048), and negative with insulin (r=-0.429; p=0.005), HOMA (r=-0.446; p=0.003) and BChE (r=-0.522; p<0.001). Ghrelin showed negative correlation with estradiol (r=-0.701; p=0.004). BChE was negatively correlated with estradiol (r=-0.441; p=0.018) and glucose (r=-0.343; p=0.028), and positively with insulin (r=0.460; p=0.003) and HOMA (r=0.505; p<0.001). In conclusion, changes in metabolic biomarkers occur in bitches after LH peak, characterized by increased lipids (total cholesterol, HDL cholesterol and LDL cholesterol) without changes in BChE activity, and increased adiponectin and ghrelin concentrations, without significant changes in glucose and insulin.

The accuracy and reproducibility of the endometrial receptivity array is superior to histology as a diagnostic method for endometrial receptivity

To compare the accuracy and reproducibility of the endometrial receptivity array (ERA) versus standard histologic methods. A comparative prospective study (May 2008-May 2012). University-affiliated infertility clinic. Eighty-six healthy oocyte donors, regularly cycling, aged 20-34 years with a body mass index (BMI) of 19-25 kg/m(2). Endometrial biopsies were collected throughout the menstrual cycle. For the accuracy study, 79 samples were grouped into two cohorts: the training set (n = 79) for ERA machine-learning training and dating, and a dating subset (n = 49) for comparison between histologic and ERA dating. For the reproducibility study, seven women underwent ERA testing and it was repeated in the same patients on the same day of their cycle 29-40 months later. Concordance of histologic and ERA dating related to LH as a reference, and interobserver variability between pathologists were statistically analyzed by the quadratic weighted Kappa index. The ERA reproducibility was tested and its gene expression visualized by principal component analysis. For each pathologist, concordance against LH peak yielded values of 0.618 (0.446-0.791) and 0.685 (0.545-0.824). Interobserver variability between pathologists yielded a Kappa index of 0.622 (0.435-0.839). Concordance for ERA dating against LH peak showed a value of 0.922 (0.815-1.000). Reproducibility of the ERA test was 100% consistent. The ERA is more accurate than histologic dating and is a completely reproducible method for the diagnosis of endometrial dating and receptivity status.

Precocious puberty in Turner Syndrome: report of a case and review of the literature

IntroductionTurner Syndrome (TS) is caused by monosomy or structural abnormalities of the X chromosome, with a prevalence of about 1/2000 females live birth. Most important clinical features of TS are short stature and gonadal failure. Approximately one third of girls with TS may undergo spontaneous puberty. Here we report on the case of a girl with a rare 45X0/47XXX mosaic TS exhibiting a precocious puberty.Case reportThe patient was diagnosed with TS at the age of 4 years, upon a diagnostic work-up for dysmorphic features. Chromosome analysis revealed a mosaic karyotype (45X0/47XXX). She presented with normal height and normal growth velocity so that Growth Hormone (GH) therapy was not started. She was referred to our Department at the age of 7 years and 10 months, because of vaginal bleeding. A physical examination revealed a Tanner stage III for breast and Tanner stage III for pubic hair development. Height and weight were within the normal range for age. Psychological evaluation showed moderate global developmental delay, together with emotional and social immaturity and reading difficulties. The growth rate was accelerated. Her bone age was 10 years. Pelvic ultrasound demonstrated increased size for age of both the uterus and the ovaries, with bilateral ovarian follicles. GnRH stimulation test revealed pubertal response of gonadotropins (peak LH 22.5 mIU/ml). MRI of the brain was normal. These clinical, radiologic and laboratory findings were consistent with a diagnosis of idiopathic central precocious puberty; therefore, GnRH analog therapy was started, in order to slow pubertal progression and to preserve adult stature. Furthermore, GH treatment was added to further improve adult height.ConclusionOur case highlights the possibility of precocious puberty as an atypical clinical feature of TS. Thus, precocious puberty may occur in TS girls when a dosage compensation by the cell line with more than two X chromosomes allows normal ovarian function. GnRH analog therapy in addition to GH treatment should be recommended in TS girls with precocious puberty in order to slow pubertal progression and to preserve adult stature.

Unpredicted ovulations and conceptions during early pregnancy: an explanatory mechanism of human superfetation

In this bioessay, a literature review on human superfetation was performed in order to find epidemiological variables associated with this phenomenon. Thereafter, an explanatory mechanism of superfetation compatible with the endocrinological, histological and physiological changes undergone by women during early pregnancy is proposed. Superfetation can be defined as the ovulation, fertilisation and implantation of a second or additional embryo(s) during pregnancy. The literature review evidences a small discordance in gestational age between dizygotic twins in humans (range: 2-4 weeks; mean ± s.e.m.: 3.3 ± 0.3 weeks). This difference is compatible with a luteal out-of-phase (LOOP; i.e. atypical increase in E2 levels in the mid-luteal phase)-like event occurring between 1 and 3 weeks after the ovulation that allowed the first pregnancy to take place. The LOOP-like event may allow passive sperm transport from the vaginal fornix to the Fallopian tube ipsilateral to the ovulatory ovary and trigger a LH peak and ovulation. Furthermore, during very early pregnancy, the decidual reaction is not yet completed and at least one proximal Fallopian ostium may be opened, allowing the passage of the spermatozoa ascending to the fertilisation site and the extra embryo(s) descending to the implantation site(s).

Comparison of Detection of Normal Puberty in Boys by a Hormonal Sleep Test and a Gonadotropin-Releasing Hormone Agonist Test

The magnitude of sleep-related gonadotropin rise required to activate pubertal gonadal function is not established. Our objective was to determine the normal relationship between sleep-related pubertal hormone levels and pituitary-testicular responsiveness to a GnRH agonist (GnRHag) test across the pubertal transition. DESIGN/SETTING AND PARTICIPANTS: We conducted a prospective study in a General Clinical Research Center with healthy 9- to 15-yr-old volunteer boys. INTERVENTIONS included overnight blood sampling followed by leuprolide acetate injection (10 μg/kg). LH, FSH, and testosterone levels were evaluated. LH levels during sleep and post-GnRHag rose steadily during the late prepubertal years. Sleep peak LH correlated highly with the LH response to GnRHag across groups (r = 0.913). A sleep peak LH level of at least 3.7 U/liter predicted pubertal testicular activation with 100% accuracy. LH of at least 14.8 and at least 19.0 U/liter 4 h after GnRHag, respectively, predicted puberty with 100% sensitivity/94% specificity and 100% specificity/94% sensitivity. Overweight pubertal boys had transiently prolonged responses to GnRHag. FSH rose during both waking and sleeping hours during the prepubertal years, and all pubertal boys had an FSH level of at least 0.9 U/liter awake and at least 1.2 U/liter asleep. Sleep LH was more closely related than FSH to testicular size. These data suggest that a critical LH level during sleep (≥3.7 U/liter) heralds the onset of pubertal virilization and that this level is predictable by LH of at least 14.8-19 U/liter 4 h after GnRHag. These data also suggest that LH stimulation of testicular androgen production plays a role in stimulating testicular tubule growth once a critical level of FSH is achieved.

Urine gonadotropin and estradiol levels in female very-low-birth-weight infants

BackgroundThe postnatal activation of the hypothalamic–pituitary–gonadal axis is more exaggerated in preterm than in full-term born infants and may be important for future reproductive function. AimThe objective of this study was to investigate the postnatal activation of the hypothalamic–pituitary–gonadal axis in female very-low-birth-weight infants. Study designWe performed serial measurements of gonadotropin and estradiol levels in urine samples of female very-low-birth-weight infants collected at 1 and 4weeks postnatal age, at 32weeks postmenstrual age, at expected date of delivery and at the corrected age of three and six months. SubjectsTwenty-two very-low-birth-weight infants (gestational age 25.4–30.1weeks), participating in the Neonatal Insulin Replacement Therapy in Europe trial, were included in this study. Outcome measuresGonadotropin and estradiol levels were measured in serial urine samples. ResultsLongitudinal analysis shows that after birth FSH and LH levels increase until 32weeks postmenstrual age (4weeks postnatal age) and then decrease until 3months corrected age (26weeks postnatal age). Estradiol levels decrease from 28weeks postmenstrual age (1week postnatal age) until 6months corrected age (39weeks postnatal age). ConclusionsSerial urine sampling for measurement of gonadotropin and estradiol levels provides an accurate description of the postnatal activation of the hypothalamic–pituitary–gonadal axis in very-low-birth-weight girls. Levels of FSH and LH peak at a mean postmenstrual age of 32weeks (postnatal age of 4weeks) whereas estradiol levels are highest shortly after birth.

Angiotensina-(1-7) durante o processo inicial na cascata da ovulação em bovinos

O presente estudo teve como objetivo avaliar o efeito da Ang-(1-7) e de seu receptor (MAS) na regulação da ovulação. No experimento I, utilizando um modelo in vitro de cultivo de células foliculares, foi avaliado o efeito do tratamento com Ang-(1-7) ou do bloqueio do receptor MAS através do inibidor d-Ala7-Ang-(1-7) (A-779) na expressão de RNAm para epirregulina (Ereg; um marcador inicial do processo de ovulação) em células da granulosa. No experimento II, foi utilizado um modelo in vivo de injeção intrafolicular no qual vinte vacas tiveram o ciclo estral sincronizado e, quando os folículos atingiram um diâmetro mínimo de 12mm, foi realizada a injeção intrafolicular de A-779 ou solução salina 0,9%. No momento da injeção intrafolicular, foi realizada uma aplicação IM de análogo de GnRH. A suplementação com Ang-(1-7) ou o bloqueio de seu receptor MAS em sistema de cultivo de células da granulosa não alteraram o padrão de expressão de RNAm para Ereg. A aplicação intrafolicular de A-779 (10-5M) não bloqueou a ovulação quando realizada antes do início do pico esperado de LH (100% das vacas ovularam nos grupos A-779 e controle), sugerindo que a Ang-(1-7) não possui papel relevante no início da cascata ovulatória em bovinos.

The Impact of Dietary Folate Intake on Reproductive Function in Premenopausal Women: A Prospective Cohort Study

BackgroundFolic acid is recommended to reproductive-aged women to prevent birth defects, though little is known about the effects of dietary intake on other reproductive outcomes. Improved pregnancy rates have been documented after folic acid supplement use, suggesting a possible link with ovulation, however research is limited. Our objective was to evaluate the association between dietary folate intake, hormone levels, and sporadic anovulation in healthy, regularly menstruating women.Methodology/Principal FindingsThe BioCycle study (2005–2007) prospectively followed 259 healthy women aged 18–44 years from the western New York region for up to 2 menstrual cycles. Total folate and specific sources of folate were assessed up to 4 times per cycle by 24-hour recall. Estradiol, progesterone, luteinizing hormone, and follicle-stimulating hormone were measured in serum up to 8 times per cycle, timed using fertility monitors. Anovulation was defined as a cycle with peak progesterone concentration ≤5 ng/mL and no LH peak in the mid/late luteal phase. Higher intake of dietary folate (in dietary equivalents) across tertiles had a marginally significant association with greater luteal progesterone levels (P trend 0.08). Higher intake of synthetic folate was significantly associated with higher luteal progesterone levels (P trend 0.05). Specifically, women in the 3rd tertile of synthetic folate intake had, on average, 16.0% (95% CI, 0.5–33.8%) higher luteal progesterone levels compared to women in the 1st tertile. Moreover, consumption of synthetic folate was significantly and inversely associated with anovulation such that women in the 3rd tertile had a 64% (95% CI, 8–86%) decreased odds of anovulation compared to the women in the 1st tertile (P trend 0.03).Conclusions/SignificanceThese findings suggest that a diet high in synthetic folate may be associated with increased progesterone levels and lower risk of sporadic anovulation. Further study of the effect of dietary folate and folic acid supplement use on reproductive health is warranted.

Diferenças sazonais no padrão endócrino e ovariano do ciclo estral de novilhas Bos taurus indicus (Nelore)

Estrous cycle of eight Nelore heifers were evaluated during different seasons of the year (autumn n=11; winter n=8; spring n=9 and summer n=9) with daily count and measurement of follicles ≥3mm, blood was collected every 12h for LH and progesterone (P4), and after estrous every 3h for LH peak. Five ovariectomized heifers were injected with 17β-estradiol (2μg/kg) every season and blood samples collected every 3h (for 30h) thereafter for LH quantification. The monthly percent body weight difference (Δ%) did not vary among seasons. P4 concentration was higher (p&lt;0.01) and follicle number lower during autumn and summer compared to winter and spring. During winter there were more estrous cycles with three and during summer only cycles with two follicular waves (p&lt;0.01). As LH secretion did not vary despite P4 concentration and as there was negative correlation between higher P4 values and daily percentile variation of photoperiod (Δ%, p&lt;0.01; r= -0.45) it is possible to suppose that there is seasonal variation on luteal cell sensitivity to LH. In the ovariectomized Nelore heifers, the LH basal concentration (without estradiol stimulus, p=0.02) and the LH response to estradiol (p&lt;0.01) were lower during summer, leading to the hypothesis that there is seasonal variation of hypothalamic sensitivity to estradiol. According to the present experiment there are suggestions of seasonal reproduction in Nelore heifers.

Impact of the prostaglandin synthase-2 inhibitor celecoxib on ovulation and luteal events in women

BackgroundOvarian prostaglandins are critical in normal ovulation processes; thus, their inhibition may provide contraceptive benefits. This study was performed to determine the effect of the cyclooxygenase-2 (COX2) inhibitor celecoxib on ovulation and luteal events in women. Study DesignThe study had a randomized, double-blind, crossover design. Ovulatory, reproductive-aged women underwent ovarian ultrasound and serum hormone monitoring during four menstrual cycles (control cycle, treatment cycle 1, washout cycle, treatment cycle 2). Subjects received study drug (oral celecoxib 400 mg or placebo) either (a) once daily starting on cycle day 8 and continuing until follicle rupture or the onset of next menses if follicle rupture did not occur [pre-luteinizing hormone (LH) surge dosing] or (b) once daily beginning with the LH surge and continuing for 6 days (post-LH surge dosing). Subjects were randomly assigned to one of the above treatment schemes and received the other in the subsequent treatment cycle. The main outcomes were evidence of ovulatory and luteal dysfunction as determined by inhibited/delayed follicle rupture and reduced luteal progesterone synthesis or lifespan, respectively. ResultsA total of 20 women enrolled and completed the study (Group 1=10, Group 2=10), with similar demographics between groups. Nineteen subjects exhibited normal ovulation in the control cycle (one had a blunted LH peak). In comparison to control cycles, treatment cycles resulted in a significant increase in ovulatory dysfunction [pre-LH treatment: 30% (6/20), p=.04; post-LH treatment: 25% (5/20), p=.04]. Mean peak progesterone, estradiol, and LH levels and luteal phase length did not differ significantly between control and either treatment cycle. ConclusionsAlthough treatment with celecoxib before or after the LH surge increases the rate of ovulatory dysfunction, most women ovulate normally. Thus, this selective COX2 inhibitor appears to be of limited usefulness as a potential emergency contraceptive.

The Utility of Menstrual Cycle Length as an Indicator of Cumulative Hormonal Exposure

Associations between menstrual cycle length and chronic diseases are hypothesized to be due to differences in underlying hormonal patterns. The aim of the study was to evaluate the association between menstrual cycle length and the hormonal profile and anovulation. We conducted a prospective cohort study at the University at Buffalo from 2005 to 2007. We recruited 259 healthy, regularly menstruating women aged 18-44 yr. Cycle length was observed for up to two cycles. Serum estradiol, progesterone, LH, and FSH were measured up to eight times per cycle for up to two cycles. Women with short cycles (<26 d) had higher FSH concentrations during menses and in the late luteal phase, higher follicular estradiol concentrations, and lower LH concentrations across the cycle. Among women with longer cycles (>35 d), estradiol and LH peaks occurred on average about 3 d later, and FSH peaks about 1 d later compared to women with normal-length cycles. Both short and long cycles, compared with normal-length cycles, had an increased probability of anovulation. In general, per-cycle exposure to hormones was less in short cycles based on the area under the curve, although over time the cumulative exposure to estradiol would be greater for women with short cycles. Short ovulatory cycles were associated with higher follicular phase estradiol, an earlier rise in FSH, and an increased risk of anovulation. These results suggest that menstrual cycle length may be a relevant indicator of estradiol exposure and risk of anovulation among regularly cycling women.

Echocardiographic and Doppler assessment of maternal cardiovascular function in normal and abnormal canine pregnancies

The objective was to verify maternal hemodynamic differences between normal and abnormal pregnancies in dogs. Brucella-negative pregnant bitches (n = 31) were retrospectively classified into abnormal (which had either their pregnancy interrupted between Days 52 and 60 or perinatal death of more than 50% of the litter; n = 14) and normal (which had delivered healthy puppies at term; n = 17). These dogs were evaluated with echocardiography every 10 days from Days 0 to 60 of gestation (Day 0 = estimated day of LH peak). Systolic blood pressure was also assessed. At Day 50 of gestation, left ventricular free wall in systole increased in the normal but not in the abnormal group (P < 0.01). In contrast, end systolic stress (P < 0.01) and systolic blood pressure (P < 0.01) diminished only in normal animals. We concluded that signs of altered maternal cardiovascular adaptation to pregnancy may be predictors of obstetrical complications in dogs.