Endocrine Abstracts

Fertility preservation is a rapidly advancing area of medicine. Its clinical potential in adult women was demonstrated by ovarian function and successful pregnancy following ovarian cortical tissue cyropreservation and replacement in the sheep in the 1990s with the first successful human pregnancy reported in 2004. Since then some 25 babies have been born to women who have had ovarian tissue cryopreserved and subsequently replaced, with most of these women having been treated ...

Background: Sex-steroid feedback regulates gonadotropin (LH and FSH) secretion. Kisspeptin, a novel hypothalamic neuropeptide, stimulates gonadotropin secretion by stimulating GnRH secretion, and has been shown in animal models to play a central role in mediating sex steroid feedback.Hypothesis: As estrogen feedback occurs at both the hypothalamus and the pituitary in women, we hypothesized that the stimulatory effect of kisspeptin-10 would be dependent ...

BackgroundSerum testosterone remains the most important investigation in the diagnosis of androgen deficiency in men. Most of the circulating testosterone is bound to albumin and sex hormone binding globulin (SHBG), whereas free testosterone accounts for approximately 2% of total testosterone. Because direct measurement of free testosterone is impractical in routine practice, several equations have been used to provide clinically useful estimates of free...

Testicular cancer has a peak incidence in young men between the ages of 15 and 40, with an increased frequency in individuals with disorders of the reproductive tract such as hypospadia and cryptorchidism. It has been proposed that carcinoma in situ cells are derived from testicular germ cells that have not differentiated appropriately during fetal life, perhaps as a result of disturbance of the hormonal environment. The aim of this study is to investigate whether estrogen may...

Synthetic C19 gestogens which are used in combination with testosterone as hormonal contraception in men bind to both the androgen and progesterone receptor. The relative contribution of these two components is unclear. In this study, we have compared the effect of a synthetic gestogen (desogestrel) with naturally occurring progesterone on the pattern of secretion of LH and FSH in healthy volunteers. Twenty men aged 18-40 were randomised to receive either progesterone (gestone...

Hormonal male contraceptives suppress gonadotropin secretion to induce azoospermia. These also markedly reduce the testicular production of testosterone. To prevent hypogonadism, pharmaceutical preparations of testosterone therefore need to be administered as a replacement therapy. Peripheral testosterone concentrations thus reflect the exogenous hormone rather than testicular production. However because the testis contributes approximately 95% of epitestosterone (E) productio...

BACKGROUND: Male steroidal contraceptive regimens achieve azoospermia in 60-90% of Caucasians. The mechanisms underlying this heterogeneity in response are not clear. The aim of this retrospective study was to examine a number of polymorphisms in genes involved in androgen metabolism and action, in azoospermic responders (n=73) and oligozoospermic non-responders (n=44) from previous contraceptive trials. METHODS: Local Ethical Committee approval was obtained. DNA was extracted...

Context: In rodents, in-utero exposure to the exogenous oestrogen diethylstilboestrol (DES) results in reproductive abnormalities in male offspring. It has been proposed that similar anti-androgenic effects also occur in the human fetal testis following oestrogen exposure.Objective: Determine effects of DES exposure on testosterone production by normally growing human fetal testis xenografts.Design: Human fetal testes (15&...