Endocrine Abstracts

Testosterone therapy has been shown to benefit men with heart failure or coronary artery disease, an activity proposed to be mediated via its vasodilatory efficacy. Testosterone has been demonstrated to dilate human coronary arteries, but it is unknown whether testosterone has a similar action in human pulmonary or systemic vessels.Male patients were recruited from cardiothoracic (n = 14, age = 68 plus/minus 9) or gastrointestinal (n = 8, age = 70 plus/minus 3) operating l...

Background: Testosterone treatment has been shown to increase exercise capacity in men with chronic heart failure but the mechanism of benefit is unclear. The purpose of this study was to examine the acute haemodyamic effects of testosterone in men with heart failure.Methods: Twelve men with stable heart failure (age 62.8 (8.8)years; ejection fraction 30.9 (6.3)% (NR>60%)) were enrolled in a double-blind, placebo-controlled cross-over study. Cardiac o...

Objectives: Testosterone deficiency has been associated with depressive symptoms, which may be improved by replacement therapy. Patients with chronic heart failure have a high prevalence of depression, which is associated with early mortality in these patients. Men with heart failure may also have low plasma levels of testosterone, which could contribute to depressed mood. In a clinical study investigating whether testosterone treatment benefits men with heart failure, patient...

Background: Current evidence suggests that testosterone acts as a vasodilator in several vascular beds. This may have implications for men who are androgen deficient, in whom vascular reactivity may be impaired. We have studied vascular responses in vitro in femoral arteries from testicular feminised mice (Tfm), which lack a functional androgen receptor and are consequently androgen resistant and have reduced circulating levels of testosterone. Methods: Femoral arteries from m...

Intro: A subset of pancreatic and gastric neuroendocrine tumours (NET) are associated with hypercalcaemia attributed to tumour secretion of parathyroid hormone related peptide (PTHrP). Hypercalcaemia may be severe and refractory to conventional treatment....

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...