OBJECTIVES Previous data have shown that inhibin A (alpha/betaA) is increased about twofold in maternal serum samples from Down syndrome pregnancy. Our objectives were to determine whether activin A (betaA/betaA) was similarly increased in maternal serum from pregnancies affected with fetal Down syndrome, and to investigate whether increased expression of each inhibin/activin subunit occurred i...

The aim of the present study was to evaluate inhibin secretion in rats with autoimmune orchitis. As we have previously described, experimental autoimmune orchitis (EAO) induced in rats by active immunization with testis homogenate and adjuvants is characterized by an interstitial mononuclear cell infiltrate and sloughing of the germinal epithelium. At 120 days after the first immunization 60% o...

Inhibin and activin are members of the transforming growth factor beta (TGFbeta) family of cytokines produced by the gonads, with a recognised role in regulating pituitary FSH secretion. Inhibin consists of two homologous subunits, alpha and either betaA or betaB (inhibin A and B). Activins are hetero- or homodimers of the beta-subunits. Inhibin and free alpha subunit are known products of two ...

The gonadal hormone inhibin regulates daily sperm production (DSP) indirectly through negative feedback control of FSH secretion and may also affect DSP via direct actions within the testis. Studies attempting to increase DSP through the immunization against inhibin have yielded equivocal results. The current study compared 2 inhibin antigens for effects on DSP and hormone secretion. Hampshire ...

Inhibin B is a product of the gonads and a marker for ovarian follicular development. This was a cross-sectional study designed to assess awakening of the reproductive function by studying secretion pattern of inhibin B during the weight restoration in patients with anorexia nervosa (AN). Twenty patients with AN participated at low weight [body mass index (BMI) 14.3 +/- 0.3 kg/m(2))], 22 partia...

Transforming growth factor-beta (TGFbeta) homologues form a diverse superfamily that arose early in animal evolution and control cellular function through membrane-spanning, conserved serine-threonine kinases (RII and RI receptors). Activin and inhibin are related dimers within the TGFbeta superfamily that share a common beta-subunit. The evolution of the inhibin alpha-subunit created the only ...

Inhibin activity was measured by bioassay in follicular fluid of 99 individual ovine follicles ranging from 1 . 4 to 6 . 8 mm diameter (used to calculate volume) and in various stages of atresia. Treatment of samples before assay with charcoal concentrations of greater than 1 mg/ml resulted in significant loss of inhibin activity. The inhibin content of follicular fluid from individual follicle...

Changes in serum immunoreactive (IR)-inhibin were measured by RIA in two studies, in order to elucidate, firstly whether the pattern of IR-inhibin secretion is similar to that of estradiol (E2), and secondly, whether inhibin suppresses endogenous FSH release. Study 1: Purified urinary FSH (pFSH) or human menopausal gonadotropin (hMG) were daily injected intramuscularly into women with hypogonad...

BACKGROUND We have demonstrated that growth differentiation factor 9 (GDF9) enhances activin A-induced inhibin β(B)-subunit mRNA levels in human granulosa-lutein (hGL) cells by regulating receptors and key intracellular components of the activin signaling pathway. However, we could not exclude its effects on follistatin (FST) and follistatin-like 3 (FSTL3), well recognized extracellular inhibit...

In addition to the regulation of FSH secretion, it has been clearly shown that inhibin and activin have paracrine/autocrine effects in the gonads. We have studied the effect of human recombinant inhibin A and human recombinant activin A on immature porcine Leydig cells in vitro. Leydig cells were prepared by collagenase digestion of testes from 3-week-old piglets, purified on Percoll gradient, ...