OBJECTIVE The aim of the study reported here was to investigate the protective effect of gonadotropin-releasing hormone analog (GnRHa) against cyclophosphamide (CTX)-induced gonadotoxicity. METHODS Eighty Fischer 344 rats were divided randomly into four groups (20 per group). One group received normal saline, one GnRHa, one CTX, and one GnRHa+CTX. Several parameters were used to observe the o...

Reproductive failure associated with heat stress is a well-known phenomenon. The mechanism involved in this failure is not clearly understood. In order to test a possible direct effect of heat stress on ovarian function, 36 White Leghorn laying hens were housed in individual cages in 2 temperature- and light-controlled rooms (n = 18). At 31 wk of age, one group was exposed daily for 12 h to hig...

BACKGROUND Elevated early follicular phase (EFP) FSH is frequently observed in subfertile patients. In these women, temporary normalization of FSH concentrations is known to occur. We studied the complete endocrine cycle profile of subfertile young women with elevated basal FSH compared with controls. METHODS Daily bloodsampling and ultrasound monitoring in the follicular phase was performed in...

BACKGROUND Altered somatotrophic signaling is among the most important potential mechanisms of extended longevity. Ames dwarf (df/df) mice are homozygous for mutation at the Prop-1 gene, leading to a lack of growth hormone (GH), prolactin and thyroid stimulating hormone (TSH). Mice homozygous for targeted disruption of the growth hormone receptor/growth hormone binding protein gene are known as...

OBJECTIVE To generate estimates of the association between markers of ovarian aging and natural fertility in a community sample at risk for ovarian aging. METHODS Women aged 30-44 years with no history of infertility who had been trying to conceive for less than 3 months provided early-follicular phase serum and urine (N=100). Subsequently, these women kept a diary to record menstrual bleedin...

Previous studies relating hormone and cytokine concentrations in follicular fluid to oocyte fertilizability were flawed by the uncertainty about the actual oocyte maturity status at the time of recovery and by the possible contribution of the male factor to failures of conventional in-vitro fertilization. This is the first study in which oocyte maturity was assessed immediately after recovery a...

Patients with severe idiopathic constipation are almost exclusively women of reproductive age. To investigate the possibility of a sex hormone abnormality in this condition, we have compared a range of sex hormones during the follicular and luteal phases of the menstrual cycle in 23 healthy women (mean age 33 years) with those in 26 patients with severe idiopathic constipation (mean age 32 year...

PURPOSE Tamoxifen is an anti-estrogenic drug that is widely used for endocrine-dependent breast cancer as adjuvant hormonal therapy, and its use has been reported to be frequently associated with high levels of serum estradiol. Since the population of premenopausal women receiving tamoxifen therapy is growing in Japan, we retrospectively analyzed the incidence of ovarian hyperstimulation by tam...