Endocrine Abstracts

Chronic heart failure (CHF) is associated with maladaptive and prolonged neurohormonal and pro-inflammatory cytokine activation causing a metabolic shift favouring catabolism, vasodilator incapacity, and loss of skeletal muscle bulk and function. In men, androgens are important determinants of anabolic function and physical strength and also possess anti-inflammatory and vasodilatory properties. We conducted a randomised, double blind, placebo controlled trial of testosterone ...

Testosterone is a coronary vasodilator and is known to increase ischaemic threshold in men with angina. We have previously demonstrated that testosterone inhibits the pore forming alpha1c subunit of the cardiovascular L-type calcium channel transfected into HEK293 cells. In this study we have investigated the effect of testosterone on potassium-stimulated extracellular calcium entry in A7r5 vascular smooth muscle cells (VSMCs).A7r5 cells grown...

Testosterone has immune-modulating properties and current in-vitro evidence suggests that testosterone may suppress the expression of the pro-inflammatory cytokines Tumour Necrosis Factor (TNF alpha), interleukin (IL)-1 beta and IL-6 and potentiate the expression of the anti-inflammatory cytokine IL-10. We report a randomised single-blind placebo-controlled crossover study of testosterone replacement (Sustanon 100) versus placebo in 27 men (age 62+-9years) with symptomatic and...

Testosterone therapy has been shown to be beneficial in men with coronary artery disease (CAD) and chronic heart failure (CHF), effects which are proposed to be due to a direct vasodilatory action. We utilised fluorescence measurements to investigate whether testosterone inhibits extracellular calcium entry induced by 50mM high potassium (K+) buffer, in A7r5 vascular smooth muscle cells.A7r5 cells were grown on coverslips in 12-well plates in ...

Testicular feminised (Tfm) mice bear an X-linked, single base pair deletion in the gene encoding the classical androgen receptor(1) consequently these animals express a truncated, non-functional form of the receptor protein. Affected animals (XTfmY) are rendered insensitive to actions mediated via this receptor. The Tfm mouse is therefore an excellent model for studying non-genomic testosterone signalling mechanisms. Unfortunately, Tfm mice are also deficient in the...

A 32 year old man with a history of epilepsy since childhood presented in 1992 with a grand mal seizure and clinical features of tuberous sclerosis (TSC). One year later he was referred with classical Cushingoid features. His serum Na was 140 mmol/l, K 3.4 mmol/l, 9 AM cortisol 1018 nmol/l with lack of diurnal variation and ACTH 42-50 ng/l. Urinary cortisol: 797 nmol/24 h. After overnight, low and high dose dexamethasone suppression, cortisol was 1018, 1154, and 62 nmol/l resp...

Testosterone improves symptoms and exercise capacity in men with heart failure (Pugh et al., Heart, 2003, In Press), and has been demonstrated to lower peripheral vascular resistance in such individuals (Pugh et al., Eur.Heart J. 2003, 24, 909-15), consistent with a systemic vasodilatory activity. The vasodilatory mechanism of testosterone has yet to be investigated in the systemic vasculature. Mesenteric tissue was obtained from male patients (n=14, age=70+2), undergoing gast...

We(1) and others have established that men with coronary heart disease (CHD) have lower serum testosterone levels than men with normal coronaries. Hypotestosteronaemia is associated with dyslipidaemia, visceral obesity, insulin resistance, hypertension and a prothrombotic state.The aim of this study was to determine the prevalence of hypogonadism in men with CHD proven by either greater than 70 per cent stenosis of one or more epicardial or greater than 50 per cent stenosi...

Objectives: Pro-inflammatory cytokine levels are elevated in heart failure and have been implicated in disease progression. Testosterone has been shown to have anti-inflammatory properties and plasma levels may be reduced in men with heart failure. We studied the relation of endogenous testosterone with plasma cytokines in men with chronic heart failure and the effects of testosterone administration.Methods: Baseline plasma levels of total and bio-avail...

Background: Testosterone has been shown to have anti-inflammatory properties and may suppress production of pro-inflammatory cytokines. In this study, we examined the effects of testosterone on the ex-vivo production of the anti-inflammatory cytokine interleukin- (Il-)10 in whole blood from hypogonadal men.Method: 16 men with new diagnosis of hypogondism were studied. Mean age was 61.7 (2.9) years, plasma total testosterone was 6.4 (0.4) nM. Blood was c...