Endocrine Abstracts

The major glucocorticoids (cortisol in man and corticosterone in the rat) play an important role in obesity and its attendant hypertension. However, there is no consistent evidence of glucocorticoid excess in simple obesity, suggesting that its role in the regulation of adipose tissue mass results from a more complex mechanism than adrenal hypersecretion of glucocorticoid. Glucocorticoid biosynthesis is not limited to the adrenal cortex; mRNA and enzymatic activity of 11β...

Adrenal steroids and alterations in steroid metabolism are important factors in the development of obesity in Zucker rats. One might predict, therefore, that the function of the adrenal gland differs between lean and obese Zucker animals. Accordingly, we investigated adrenal gland morphology and function and have considered not only glucocorticoids and HPA activity but also the renin-angiotensin-aldosterone system. Plasma samples and adrenal glands were obtained from young 12 ...

Backround: Male hypogonadism is associated with an increased incidence of cardiovascular risk factors and approximately 25% of males suffering with coronary heart disease are hypogonadal. Few studies have assessed the impact of testosterone therapy on vascular function in hypogonadal individuals and none have investigated the weekly impact of gradually reducing testosterone concentrations on vasculature.Patients and Methods: 10 hypogonadal subjects (6 wi...

Background: Men who receive gonadotoxic treatment for cancer may be at risk of hypogonadism. The extent of this risk is unknown. Severe hypogonadism is associated with fatigue, sexual dysfunction, reduced muscle mass and obesity. Diagnosing mild or moderate hypogonadism is difficult and requires evaluation.Aim: The aim of this study was to identify hypogonadism in young male survivors of cancer.Subjects and Methods: The study was a...

Corticosteroids can be synthesised in tissues other than the adrenal cortex but the contribution of this extra-adrenal corticosteroidogenesis to circulating levels in man is not known. We studied this in a group 10 subjects taking chronic glucocorticoid replacement following bilateral adrenalectomy. In phase 1, they were maintained on cortisol alone (30 mg/day). In phase 2, cortisol was replaced by dexamethasone (2 mg/day) and in phase 3, they received both cortisol and dexame...

Bile acids inhibit glucocorticoid and mineralocorticoid metabolism. However bile acids may also influence hormone action by modulating steroidogenesis in the adrenal gland. In rodents adrenal cholesterol supply for steroidogenesis is derived from circulating HDL through the actions of scavenger receptor SR-B1. Since hepatic SR-B1 expression is known to be regulated by bile acids, we have investigated whether adrenal SR-B1 is similarly affected and, if so, whether adrenal lipid...

We have shown that linked polymorphisms in the aldosterone synthase gene (CYP11B2) are associated with hypertension and altered aldosterone production. However, the most consistent intermediate phenotype associated with this genetic variation is increased plasma 11-deoxycortisol (S) and urinary excretion of its metabolite, tetrahydrodeoxycortisol (THS); this is paradoxical as S is a substrate for the enzyme 11beta-hydroxylase, encoded by the neighbouring gene, CYP11B1. However...

A 22 year old lady, in her third pregnancy, presented at 35 weeks gestation with modest hypertension (BP 130/90). She was known to carry a high risk mutation for Von Hippel Lindau syndrome with no prior disease manifestations. Urinary catecholamine levels were normal at 18 weeks gestation and she remained asymptomatic throughout her pregnancy. Repeat measurement at 35 weeks demonstrated elevated noradrenaline and normetadrenaline values (1761 nmol/24h and 9.69 micromol/24h res...

Microprolactinomas are the commonest pituitary tumour and respond well to dopamine agonist (DA) therapy with resolution of symptoms and tumour shrinkage occurring in the vast majority of cases. Reports also suggest that up to 20% of cases may achieve long-term normoprolactinaemic remission following withdrawal of chronic dopamine agonist therapy yet interruption of therapy is not universally practised nor is there consensus on the duration of therapy. In this retrospective stu...

11Beta-Hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) catalyse the synthesis of corticosterone and aldosterone respectively in the rat adrenal cortex. Recent studies have shown that CYP11B1 and CYP11B2 are also expressed in the central nervous system (CNS) but little is known about their regulation. In this study, we have quantified CYP11B1 and CYP11B2 gene expression in the CNS following treatment with ACTH and dexamethasone.Three groups of ma...