Inhibin is a gonadal glycoprotein believed to be important in the regulation of pituitary FSH secretion and/or to function as a paracrine factor within the ovary and testis. We studied serum levels of inhibin, oestradiol (E2), progesterone (P), FSH and LH during the periovulatory interval in order ...

No effective hormonal contraceptive has yet been devised for men. Through their suppressive effect on gonadotropin secretion, GnRH antagonists inhibit both testosterone (T) production and spermatogenesis in animals. Long term administration of an antagonist alone would result in androgen deficiency; ...

The gonadotropin secretion pattern in normal reproductive age women (n = 5) was evaluated for the presence of a circadian rhythm. The women volunteered for a series of 24-h admissions in different phases of their menstrual cycles (early follicular, late follicular, and midluteal). Plasma LH and FSH ...

No abstract or description.

The development of a safe, well-tolerated, effective, and reversible male hormonal contraceptive would be a major clinical advance for couples planning their family size and for control of population growth. High-dosage parenteral testosterone (T) esters alone or in combination with a progestogen ...

Acyline is a novel GnRH antagonist that reliably inhibits gonadotropins and testosterone (T) levels in men for 48 h after a single dose up to 75 microg/kg. In this study we examined gonadotropin and T levels in 28 healthy young men administered acyline as single doses of 150 or 300 microg/kg or serial injections of 75 microg/kg. ...

In the adult male, the testes produce both sperm and testosterone. The function of the testicles is directed by the central nervous system and pituitary gland. Precise regulation of testicular function is conferred by an elegant feedback loop in which the secretion of pituitary gonadotropins is ...

The concentration of lipoprotein(a) [Lp(a)] in human plasma is largely genetically determined and is inversely correlated to the size of apolipoprotein(a) [apo(a)]. Additionally, Lp(a) values are relatively stable within individuals and are only marginally susceptible to therapeutic treatment. The ...

Inhibin is a glycoprotein hormone produced by the testis and ovary which is postulated to be an important regulator of pituitary FSH secretion. Animal data indicate that inhibin is produced by the Sertoli cells of the testis under the influence of FSH. To determine the role of FSH withdrawal and ...

OBJECTIVE: To evaluate the ability the Nal-Lys GnRH antagonist ([N-Ac-Nal (2)1, 4ClDPhe2, D3Pal3, Lys (Nic)5, D-Lys(Nic)6, Lys (iPr)8, D-Ala10] to suppress gonadotropins and T in humans and to assess its duration of action and its local effects. DESIGN: Placebo-controlled clinical study. SETTING: ...