Endocrine Abstracts

Inhibin B is a product of the gonads and it is a marker for ovarian follicular development. We studied leptin, inhibin B and LH levels in two groups of patients with AN, at low weight (n=20, BMI=14.3 plus/minus 0.3 kg/m2) and after they reached goal weight and restore menstrual cycles (n=13, BMI 19.3 plus/minus 1.0 kg/m2). Nineteen eumenorrheic females (BMI 19.8 plus/minus 0.4 kg/m2) served as controls. At low weight in patients with AN, basal leptin (1.1 plus/minus 0.2 ng/L),...

The morphology of individual ovine placentomes is known to be influenced by several factors including; hypoxia (Gardner et.al, 2002, Placenta 23:459-466), heat stress (Bell et.al, 1987, J.Dev.Phys. 9:17-29) and the fetal and maternal nutrition (McCrabb et.al, 1991, B.J.Nutrition 65:157-168). These conditions are associated with elevated fetal plasma cortisol concentrations. However, the direct effects of fetal cortisol on placental morphology remain unknown. Hence, this study ...

Early follicular development in polycystic ovaries (PCO) is abnormal; a higher proportion of follicles have entered the growing phase than in normal ovaries [1]. IGF-I stimulates the initiation of preantral follicle growth in a human tissue culture system using a growth factor-reduced extracellular matrix, Matrigel [2]. The aim of this study was to compare the effects of IGF-I on early preantral follicle development in polycystic and normal ovaries. Small ovarian cortical biop...

Where screening for macroprolactin takes place, laboratories routinely rely on treatment of sera with polyethylene glycol (PEG) to distinguish macroprolactinaemia from true hyperprolactinaemia. However, PEG causes significant interference in some immunoassays and furthermore leads to co-precipitation of a variable amount of monomeric prolactin in addition to macroprolactin in treated sera. The aim of this study was to assess the specificity and clinical utility of alternative ...

We examined hypothyroidism control criteria in women in previous study. Part of thyroxin was replaced by 12.5 micrograms triiodthyronine (T3). After T3 treatment constant increase of the level of sex hormone binding globulin (SHBG) was observed in all cases. The aim of the study to evaluate T3 influence on testosterone level in women, SHBG level and FAI. SHBG directly determines the level of free androgen index (FAI). We have included 18 women with the increased level of FAI i...

Increasing energy intakes of sows may decrease the severity of changes in body condition occurring throughout the reproductive cycle and lead to improved efficiency of energy utilisation. The study aimed to examine the effects of feeding extra energy during late pregnancy on body fat deposition, reproductive performance and plasma insulin concentration.Twenty-four multiparous sows were randomly allocated to one of three dietary treatments. From day 85 of...

Thyroid hormones are essential for optimum fetal neurodevelopment. In-utero nutrition is dependant on adequate placentation. Epidermal growth factor (EGF) and hepatocyte growth factor (HGF) have been demonstrated to affect proliferation of human trophoblast and may therefore play a role in adequate human placentation. Intrauterine growth restriction (a process associated with malplacentation) is associated with fetal hypothyroxinemia and enhanced thyroid receptor (TR) expressi...

BACKGROUND: Hormonal male contraception is based on the reversible suppression of LH and FSH resulting in intratesticular testosterone depletion with subsequent spermatogenic arrest and infertility. Tibolone, a unique synthetic steroid with mixed progestational, androgenic and oestrogenic activities, has been shown to suppress gonadotrophins, inhibit ovulation and postmenopausal hot flushes in women. HYPOTHESIS: We hypothesise that the hybrid anti-gonadotrophic action of Tibol...

Macroprolactin has reduced bioactivity and accumulates in the sera of some subjects, resulting in apparent hyperprolactinaemia. Development of the polyethyleneglycol (PEG) precipitation technique has enabled large-scale screening for macroprolactin in hyperprolactinaemic subjects. We have reviewed the experience of routine screening for macroprolactin using PEG precipitation over a 54-month period in a single centre.Plasma levels of prolactin exceeded 50...

IntroductionOvulation involves rupture of the ovarian surface, and thus the ovarian surface epithelium (OSE) is subjected to serial injury and repair with each ovulatory cycle. Inflammation is integral to the process of ovulation, but importantly, inflammatory damage is also thought to be a potential mechanism of ovarian tumour development. We have examined OSE responses to an inflammatory stimulus associated with ovulation, Interleukin-1alpha (IL1alpha)...

Ligand-activated peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear hormone receptor, dimerises with retinoid X receptor(RXR) and acts as a transcription factor translating nutritional, pharmacological and metabolic stimuli into changes in gene expression. PPARgamma is thought to serve several roles in adipocyte differentiation, fatty acid and lipid metabolism, insulin sensitivity and ovarian steroidogenesis. PPARgamma has also been shown to increase gluco...

BackgroundCurrent techniques to study the early stages of follicular development (i)in vitro(/i) are handicapped by the spontaneous wholesale transition of primordial to primary follicles and by primary follicle arrest. We have circumvented this problem by culturing fragments of ovarian cortical tissue on the chorioallantoic membrane (CAM) of chick embryos and shown it to be successful for the (i)in ovo(/i) culture of cortical slices from a variety of sp...

Effects of paint thinner inhalation on serum testosterone synthesis and secretion were investigated in the male rat. A control group inhaled normal air ventilation. The remaining animals were divided into three groups and exposed to paint thinner in a glassy cage for 15 and 30 days. A group of animals was allowed to recover for 15 day after 30 days of exposure. Toluene concentration (the largest constituent in thinner, 66%) was set at 1500 ppm in the inhalation air. At the end...

This study was undertaken to examine the effects of leptin on testicular histology in mice. Animals were divided into two groups. Group I served as controls. Mice in Group II were injected daily with leptin for five days. All animals were killed by decapitation at the end of the experiment. The testes were removed and weighed out. Some of the testicular tissue specimens were used for light and electron microscopic examination. The remaining samples were processed for semiquant...

Ghrelin, a recently isolated hormone, has been reported to have modulatory effects on smooth muscle contractility. In this study, we investigated the effects of ghrelin on spontaneous contractions in the rat uterus in vitro.Myometrium strips were removed from Wistar rats following decapitation and placed in a jacked tissue bath containing Krebs solution at 37 oC and pH 7.4, constantly bubbled with 95% oxygen and 5% carbon dioxide. The myometrial strips w...

BackgroundSomatostatin (sst) acts via a series of 5 G-coupled receptors (sstr1-5) which control exocrine and endocrine secretions and also regulate cellular proliferation and apoptosis in many parts of the body. Recent experimental data suggests that sst plays a roles in ovarian function and the synthetic sstr agonists octreotide has been used in the treatment of polycystic ovarian syndrome. We have investigated the expression of somatostatin receptors (...

Anti-Mullerian hormone (AMH) is expressed in the ovary, in granulosa cells (GC) of preantral and antral follicles. Mice lacking the AMH gene show an increase in the proportion of early growing follicles and a reciprocal decrease in the primordial pool, suggesting an important role in early follicle growth. Little is known about the expression of AMH in the human ovary. Recent studies have shown that the proportion of follicles entering the growing pool is increased in PCO, sim...

Objectives: To assess the gonadotrophin suppressive effects of 2 doses of nomegestrol acetate (NOMA) alone and in combination with testosterone enanthate (TE) in men.To evaluate the potential effects of NOMA on circulating lipids in menMethods: Twelve healthy male volunteers were recruited. Subjects were randomly allocated to receive either NOMA 5 milligrams or NOMA 10 milligrams orally daily. Study duration included 28 days treatm...

Turner's syndrome is the most commonly occurring chromosomal abnormality in females. Adults with Turner's have a threefold increase in mortality and life expectancy is reduced. Recent recommendations for the follow-up of women with Turner's syndrome include annual checks of thyroid function, serum lipids, blood glucose, liver function, renal function, and 3 to 5 yearly echocardiography, bone densitometry, and audiogram.We have reviewed actual follow-up m...

Observations obtained in our and other laboratories suggest that growth factors produced by glial cells, may participate in the control of LHRH-secreting neurons. In particular, utilizing GT1 cells (i.e., LHRH immortalized neurons) we have demonstrated, that transforming growth factor beta 1 (TGFbeta 1) is able to modulate the synthesis and release of LHRH from these neurons. We presently investigate the mechanism of action of this growth factor analyzing TGFbeta signaling pat...

Mullerian Inhibiting Substance (MIS) is a member of the transforming growth factor beta superfamily of growth factors, which causes regression of the Mullerian duct in male embryos, and is believed to act in a paracrine fashion after birth to regulate granulosa cell and oocyte function. MIS appears to be an important regulator of primordial follicle recruitment, and is also capable suppressing androgen production. Abnormal ovarian function is implicit in polycystic ovary syndr...

The mammalian corpus luteum secretes progesterone under the influence of luteinizing hormone (LH). LH acts by binding to its G-protein coupled receptor and elevating intracellular cAMP thus activating protein kinase A (PKA). However, the exact role of PKA in the regulation of progesterone secretion remains unelucidated. Thus in this study we have investigated the relationship between PKA expression/activity and progesterone secretion during luteinization. Human granulosa cells...

Objective: To identify the optimal regime for physiological replacement in hypogonadism. We assessed the pharmacokinetics of 3 different dose-intervals for i.m. administration of the new parenteral formulation of testosterone undecanoate in castor oil (Schering AG Berlin).Methods: Ten hypogonadal subjects (primary n equals 4 or secondary n equals 6) with a baseline T at diagnosis of less than 7 nanomols per litre were recruited and randomly allocated int...

Neurokinin B has been traditionally regarded as a neuropeptide being confined to the CNS, with no peripheral expression. This situation was the cause of some confusion as its preferred receptor (NK3R) is found mainly on peripheral organs such as the portal vein, mesenteric vessels and the heart with relatively low levels in the brain. In 2000 our laboratory reported the placenta to be an abundant peripheral endocrine source of NKB, giving rise to significant plasma concentrati...

To elucidate biochemical evidence for follicular and oocyte maturation, inhibin-A, inhibin-B and activin-A concentrations were measured in 200 follicular fluid samples from follicles ranging from 10.2mm to 36mm in diameter. Inhibin-A concentrations varied from 7.93-436 ng/ml with a mean value was 40.1ng/ml; Inhibin B concentrations varied from 9.7-786 ng/ml with a mean value of 187.3ng/ml; Activin A concentrations varied from 1.73-267.9 ng/ml with a mean value of 40.3ng/ml. Ex...

Metabolism of the dimeric glycoprotein hormone human chorionic gonadotrophin (hCG) results in the urinary excretion of hCG beta core fragment originating from the beta subunit of hCG (hCGbeta). hCG beta core fragmant retains a certain antigenic shape as well as two metabolically processed N-linked oligosaccharides. Hyperglycosylation of hCGbeta has been used as an indication of aberrant pregnancy especially in malignant disease. We have previously characterised the carbohydrat...

Background: Being little known about the biochemistry behind the follicular content or granulosa cells surrounding a mature oocyte in Assisted Reproductive Technology, our study set up to investigate the changes in steroid and cytokines' productions by cultured granulosa cells (GC) taken from individual follicles from women undergoing Controlled Ovarian Hyperstimulation (COH).MATERIALS AND METHODS: Granulosa cells isolated from 75 individual follicles we...

Macroprolactin is a high molecular weight IgG-prolactin complex which has reduced bioactivity. Macroprolactinaemia is a relatively common phenomenon, accounting for upto 20% of cases of hyperprolactinaemia in clinical practice; in the absence of amenorrhoea or hypogonadism these patients do not usually need dopamine agonist therapy. To ensure appropriate detection and management of such patients we routinely screen all serum samples with hyperprolactinaemia (>600 mU/l) for ...