Endocrine Abstracts

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...

11Beta-Hydroxylase and aldosterone synthase catalyse the synthesis of corticosterone and aldosterone in the rat adrenal cortex and are encoded by the CYP11B1 and CYP11B2 genes respectively. These genes are also expressed in distinct regions of the CNS and cardiovascular system where they may play a key role in behavioural response and blood pressure homeostasis. However, it is unclear whether this extra-adrenal expression is regulated by, or contributes to, circulating levels ...

We present two patients with unusual manifestations of sarcoidosis and review gonadal involvement in this rare but important disease. A 27 year old man presented to the Ophthalmologists at our hospital with a red eye. He was diagnosed with anterior uveitis and commenced on topical corticosteroids. Following discovery of a testicular mass, he underwent testicular ultrasonography which demonstrated bilateral hyperechoic lesions. Histological examination of an open surgical biops...

Background: The enzymes 11beta-hydroxylase and aldosterone synthase are key control steps in regulation of cortisol and aldosterone synthesis. We have previously reported that polymorphic variation of the gene encoding aldosterone synthase (CYP11B2) is associated with altered efficiency of 11b-hydroxylation of the precursor of cortisol, deoxycortisol. In order to examine this relationship in greater detail, we have studied the pattern of steroid precursor metabolite excretion ...

Aldosterone synthase catalyses the synthesis of aldosterone in the adrenal cortex and is encoded by the CYP11B2 gene. Recent studies have shown that CYP11B2 is also expressed in the central nervous system (CNS) but little is known about its regulation. In this study, we have quantitated CYP11B2 expression in the CNS following dietary manipulation of sodium and infusion of angiotensin II.In study 1, 3 groups of male WKY rats (n=6) were fed normal (0.3%), high (3%) or low (0...

INTRODUCTIONThe plasma concentrations and urinary excretion rates of 18-OH-F and 18-oxo-F are high in Conn's syndrome and glucocorticoid suppressible hyperaldosteronism, reputedly because aldosterone synthase (AS) has abnormal access to cortisol (F). However, both compounds are also excreted in normal subjects. Two enzymes, 11beta-hydroxylase (11OH) and AS, located in the zona fasiculata (ZF) and zona glomerulosa (ZG) respectively, are capable of 18-hydroxylation but only ...

Aldosterone synthase and 11beta-hydroxylase catalyse the final steps of glucocorticoid (corticosterone) and mineralocorticoid (aldosterone) production in the rat adrenal cortex. They are encoded by the CYP11B2 and CYP11B2 genes respectively. Recent studies have shown that CYP11B1 and CYP11B2 are also expressed in the brain, the vascular system and the heart where it has been suggested that aldosterone influences cardiac function and plays a role in cardiac fibrosis. However, i...