Endocrine Abstracts

Hyperprolactinemia is the most common cause of hypogonadotropic anovulation in women. It is related to an alteration of pulsatile GnRH secretion. This gonadotropic deficiency has been proposed to result from direct suppression of prolactin (PRL) on GnRH release but its mechanism remains unknown. Because GnRH neurons do not express unequivocally the PRL receptor, and are stimulated by kisspeptin (Kp) neurons which do express PRL receptors, we hypothesized that GnRH deficiency i...

Ghrelin (Ghr) acts as a link between energy balance and reproduction; hence, hyperghrelinemia reduces reproductive success. In addition, this hormone has an evident physiological role on reproduction, since Ghr and/or its receptor are synthesized by gametes/embryos and several reproductive tissues (including decidua/placenta); in addition, Ghr plasma concentration rises during gestation.The objectives of our study were to evaluate the effects of ghrelin ...

Introduction: LH and hCG act on the same receptor (LHCGR), but it is not known whether they elicit the same cellular and molecular response. This study aims at comparing the activation of cell-signalling pathways and gene expression in response to LH and hCG.Design: We evaluated the activation of cAMP, ERK and AKT-pathways and progesterone production by ELISA and Western blotting in human primary granulosa cells (hGLC) stimulated for up to 36 hours with ...

In mammals, follicle-stimulating hormone (FSH), produced by pituitary gonadotropes, is required for proper gonadal function and female fertility. The TGFβ superfamily members, activins, are critical regulators of FSH synthesis. Activins signal through heteromeric type I/type II receptor complexes and the effector proteins SMADs 2 and 3 to regulate gene transcription. Numerous studies in gonadotrope-like cell lines suggest that activin-stimulated FSH β subunit (Fshb) ...

Polycystic ovary syndrome (PCOS), the most common endocrine disorder in women in their reproductive years, is defined by two out of the following three criteria: hyperandrogenism, oligo/anovulation, and polycystic ovaries. Affected women are often obese and insulin-resistant. Recently, we developed a mouse PCOS-model through chronic exposure to dihydrotestosterone (DHT). Here, we studied whether the PCOS-phenotype remains after withdrawal of DHT treatment, which would more clo...

Kit ligand (KL)-c-kit interaction is critical for oogenesis and folliculogenesis in the ovary. However, the significance of KL-c-kit loop in ovarian steroidogenesis has yet to be elucidated. We here investigated the impact of KL-c-kit interaction in regulation of steroidogenesis using rat primary granulosa cells co-cultured with oocytes. Treatment with soluble KL suppressed FSH-induced estradiol production and aromatase mRNA expression without changing FSH-induced progesterone...