OBJECTIVE Klinefelter's syndrome (KS) is associated with hypergonadotrophic hypogonadism in adulthood. However, limited information exists about the age at which hypogonadism occurs. The hypothalamic-pituitary-gonadal (HPG) axis is transiently activated during the first months of life, offering the opportunity to study testicular function by spontaneous, basal hormone levels. The aim of this st...

Pregnant Anglo-Arab and Thoroughbred mares (n = 24) were divided randomly according to age and breed into 4 groups of 6 mares each from approximately 6 weeks before their expected foaling date. Diets received by the 4 groups varied in essential amino-acid and total protein contents. Serum progestagen, FSH and LH concentrations were determined from the day of parturition until foal heat and duri...

427 patients with varicocele ranging in age from 14 to more than 35 years underwent surgical operation during a 10 year period (1977-1986). 190 (44.5%) were referred for infertility and 365 had left-sided varicoceles (85.5%). No relationship was found between infertility and the grade of varicocele. Clinical features of prostatitis were often present. Semen analyses were performed in 37% o...

Premature ovarian failure (POF) is characterized by amenorrhea and high serum levels of follicle-stimulating hormone (FSH). POF causes female infertility and represents a substantial women's health risk affecting 1% of women by age 40. Although ovarian autoimmunity has been associated with POF, the identity of ovarian Ags recognized is unknown. In this study, we show that autoimmune-targeted di...

Synthetic luteinizing hormone-releasing hormone (LH-RH) was given in doses of 11-100 Vg to normal men. Doses of 50 and 100 t±g caused a twoto ten-fold rise in serum LH in all subjects, but in only 40% was the serum follicle-stimulating hormone (FSH) elevated. A significantly higher LH response to LHRH was seen in subjects in whom a rise in serum FSH could be detected. Although there was a wide ...

Genetically modified follitrophin receptor knockout female mice with total FSH-receptor (FSH-R) deletion are sterile and their combined estrogen deficiency-hyperandrogenemic status provides an experimental paradigm to study the effect of hormonal imbalances on ovarian function and metabolic alterations. Elevated LH levels causing hyperandrogenemia perturb normal folliculogenesis. To control div...

The nature of selection of the dominant follicle is reviewed by comparing research results between cattle and horses. In both species, emergence of a follicular wave is stimulated by an FSH surge. The surge reaches a peak by the time the follicles attain 4 mm in diameter in cattle and 13 mm in mares. In cattle, all of the growing follicles >/=5 mm contribute to the decline in FSH concentrations...

The luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone response of bull calves implanted with estradiol-17 beta to continuous and pulsatile infusion of luteinizing hormone releasing hormone (LHRH) has been examined. Estradiol-17 beta reduced serum LH and FSH concentrations and suppressed testosterone secretion and testicular growth when compared with sham-implanted bu...

Postmenopausal osteoporosis is characterized by declining estrogen levels, and estrogen replacement therapy has been proven beneficial for preventing bone loss in affected women. While the physiological functions of estrogen in bone, primarily the inhibition of bone resorption, have been studied extensively, the effects of pharmacological estrogen administration are still poorly characterized. ...

Anticancer treatment can disturb gonadal function and deplete the primordial follicle pool, leading to premature menopause. We made a prospective analysis of serum hormone levels in young female cancer survivors who had been treated during childhood and adolescence. Serum anti-Müllerian hormone (AMH) as a marker of ovarian reserve, FSH, LH, and estradiol were measured in 33 women treated previo...