Endocrine Abstracts

The effect of ovarian steroids on the vasopressin response to an osmotic stimulus in the rat has been extensively studied. Oxytocin also influences salt and water balance in the rat, but the effect of oestrogen on the response of the hormone to altered plasma sodium has not been established. Observations have been performed on rats ovariectomised under anaesthesia with and without oestrogen replacement to determine whether the response was affected by reproductive status. Fos-...

Oestrogens affect fluid balance, influencing both ingestive behaviour and renal excretion. The renal effects are partly due to altered release of the neurohypophysial hormones vasopressin and oxytocin and involve oestrogen receptor beta (ERbeta). Normal rat maintenance diet contains soya isoflavones (phytoestrogens) which are also known to act at ERbeta. A study has been performed comparing the fluid balance and neurohypophysial hormone release in rats maintained for two weeks...

Vasopressin release is stimulated following the administration of 3,4-methylenedioxymethamphetamine (MDMA ) in man. MDMA and a major metabolite, 4-hydroxy-3-methoxymethamphetamine (HMMA), have also been shown to stimulate neurohypophysial hormone release in vitro. A study has now been performed comparing the response to four other metabolites with the parent compound. Hypothalami obtained from male Wistar rats were exposed to medium alone (B1) and the medium containing ...

Ghrelin is a brain-gut peptide originally identified in the stomach. It binds to and stimulates the growth hormone secretagogue receptor type 1a (GHS-R). The presence of ghrelin in hypothalamic tissue was studied. It has been previously established that neither the synthetic GHSs, nor the endogenous hormone ghrelin, is specific for GH stimulation: they generally also stimulate the HPA axis as well as prolactin release. Since there is no direct stimulatory effect on ACTH releas...