OBJECTIVES Despite observation of adverse reproductive effects of toluene, including alterations of serum gonadotropins (luteinising hormone (LH) and follicle stimulating hormone (FSH)) in humans, little is known of the mechanism of toxicity. The hypothesis was tested that toluene acutely suppresses pulsatile gonadotropin secretion by measuring LH and FSH at frequent intervals during controlled...

Objectives—Despite observation of adverse reproductive eVects of toluene, including alterations of serum gonadotropins (luteinising hormone (LH) and follicle stimulating hormone (FSH)) in humans, little is known of the mechanism of toxicity. The hypothesis was tested that toluene acutely suppresses pulsatile gonadotropin secretion by measuring LH and FSH at frequent intervals during controlled ...

The gonadotropin-ovary axis of patients with anorexia nervosa was assessed with the aim of distinguishing between an intrinsically hypophysial deficiency and pituitary malfunction secondary to hypothalamic impairment. The most consistent endocrine abnormality was low serum luteinizing and follicle stimulating hormone (LH and FSH) levels associated with depressed serum estradiol levels. Gonadotr...

Kisspeptins have emerged as potent elicitors of gonadotropin secretion and, therefore, putative targets for pharmacological intervention. In this context, desensitization of gonadotropin responses to continuous administration of kisspeptins has begun to be characterized, but information so far available is mostly restricted to LH responses in males, whereas the similar phenomenon in females, of...

Inhibin B levels were measured in serum from 400 healthy Danish prepubertal, pubertal, and adolescent males, aged 6-20 yr, in a cross-sectional study using a recently developed immunoassay that is specific for inhibin B, the physiologically important inhibin form in men. In addition, serum levels of FSH, LH, testosterone, and estradiol levels were measured. Serum levels of inhibin B, FSH, LH, t...

Hypocretin (orexin) peptides are involved in the regulation of energy balance and pituitary hormone release. Narcolepsy is a sleep disorder characterized by disruption of hypocretin neurotransmission. Pituitary LH secretion is diminished in hypocretin-deficient animal models, and intracerebroventricular administration of hypocretin-1 activates the hypothalamo-pituitary-gonadal axis in rats. We ...

Since the male gonad is a target organ of both pituitary hormones and androgens, the present study was performed to determine whether testicular aryl hydrocarbon hydroxylase (AHH), epoxide hydrase (EH), and glutathione transferase activities and cytochrome P-450 levels were regulated by follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone. Intact, sham-operated control...

According to the endocrine model of hereditary dizygotic twinning, high FSH is responsible for multiple ovulation and pregnancy. Our study explored the underlying neuroendocrine causes. In a prospective clinical study, we compared the third day of menses parameters of episodic secretion of LH and FSH, the pituitary response to LHRH, plasma estradiol, and dimeric inhibin A and B in 16 regularly ...

BACKGROUND Premature thelarche (PT) seems to be increasing and it is difficult to differentiate its early stages from precocious puberty (PP). Clinical and biochemical parameters are warranted to differentiate the two diagnoses. METHODS One hundred ninety-one girls aged 0.5-7 years were included. Diagnoses were validated and the girls were categorized to the groups PP (n = 27) and PT (n = 164...

Associations between granins (secretogranin II (SgII) and chromogranin A and B (CgA and CgB)) and gonadotrophins (LH and FSH) have been reported in rodents and they may interact to facilitate differential storage and secretion of LH and FSH. This study investigated the relationship between granins and gonadotrophins in sheep at different stages of the oestrous cycle. Thirty-four cycling ewes ha...