Endocrine Abstracts

Regulation of many pituitary-specific genes involves calcium signalling, yet the mechanisms and signalling molecules involved have yet to be established. CaMK's are expressed in a wide variety of tissues, and are known to modulate transcriptional regulators such as MAPK's and CREB. It is unclear as to which anterior pituitary cell types express CaMK's, or which isoforms are present. We have examined the presence and localisation of type II and IV CaMK's in alphaT3-1, LbetaT2 (...

Nitric oxide (NO) is a regulator of pituitary gonadotrophs via local paracrine and autocrine actions. Gonadotrophs express neuronal nitric oxide synthase (nNOS) but the effects of NO on gonadotrophs are controversial and both stimulation and inhibition of LH release has been reported. nNOS -/- mice have reduced fertility, but this is attributed to ovary actions, because no difference was detected in basal or GnRH-stimulated LH release (Klein et al 1998). We have therefore exam...

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...

Congenital isolated ACTH deficiency (IAD) is a rare inherited disorder that is clinically and genetically heterogeneous. Patients are characterised by low or absent cortisol production secondary to low plasma ACTH despite the absence of structural pituitary defects and normal secretory indices of other pituitary hormones. When tested, there is often no ACTH response to exogenous CRH. Onset may occur in the neonatal period, but often is first observed in later childhood. Candid...