Endocrine Abstracts

PTHrP is an important factor for the regulation of calcium homeostasis around delivery. The aim of this study was to longitudinally analyse PTHrP metabolism and influencing factors looking at mothers and their breastfed newborns from 32 weeks of pregnancy until 8 weeks after delivery. Nineteen families (8 Caucasian, 11 Arabic/Asian) participated in the study. We analysed PTHrP, 25 OH vitamin D, parathyroid hormone (PTH), alkaline phosphatase, albumin; serum and urine calcium, ...

The prevalence of vitamin D deficiency in at-risk groups is rising even in sunny countries. Aim of this study was to compare vitamin D status and effect of vitamin D supplementation of moderate risk (mildly pigmented, WHO skin type 2) breastfed newborns from sunny and temperate climate zones. Newborns in Perth (30°S, group 1:5 male, 6 female) did not receive any vitamin D supplementation, newborns in Berlin (52.5°N, 17 male, 23 female) were randomised into n=2...

Type 2 diabetes mellitus is associated with increased incidence of low serum testosterone levels in men. Testosterone is known to be positively correlated with insulin sensitivity. Rosiglitazone is an insulin sensitizing agent that reduces insulin resistance by binding to PPAR gamma receptor. The purpose of this study was to determine the effect of Rosiglitazone on testosterone levels in hypogonadal men with Type 2 diabetes.This study was approved by BDG...

Introduction: Low endogenous testosterone is associated with atherosclerosis in elderly men. The aim of this study was to determine whether an inactive androgen receptor (AR) coupled with testosterone deficiency, inherent to the testicular feminised (Tfm) mouse, is associated with atherosclerosis following cholesterol feeding.Methods: Eight-week-old Tfm (n=34) and XY (n=32) littermate controls were fed for 16, 20, 24 or 28 weeks on either diet 1 (compris...

Objective: The aim of this study was to determine dosing regimen to replace testosterone to physiological levels in the testicular feminised (Tfm) mouse, and also to produce similar supraphysiological testosterone concentrations in Tfm and XY littermates.Methods: Eight-week-old Tfm (n=66) and XY littermate controls (n=24) received a single 10 microlitre intramuscular injection of testosterone (Sustanon 100 - 100 milligrams testosterone per litre, or Sust...

Hypogonadism is difficult to confirm with standard assays. A large proportion of testosterone (T) is bound to sex hormone binding globulin (SHBG) and is biologically inert. Accurate measures of free and biological-available-testosterone (Bio-T) are largely unavailable. In this study we compared formulae calculated from the total testosterone (TT) and SHBG in their ability to predict hypogonadism and/or Bio-T.TT and SHBG were determined by ELISA and Bio-T...

Low testosterone levels in men are associated with increased atherosclerosis, and testosterone replacement therapy has been shown to reduce myocardial ischemia in men with coronary artery disease. Vascular smooth muscle cell (VSMC) apoptosis is proposed to reduce plaque stability, but the role of testosterone in this process is unknown. Testosterone causes vasodilatation via calcium channel antagonism and the calcium channel antagonist nifedipine induces VSMC apoptosis. We hav...

Atherosclerotic plaque smooth muscle cells (SMCs) are sensitive to apoptotic stimuli, increasing plaque instability. Testosterone replacement therapy is beneficial in men with coronary artery disease, although its effect upon plaque stability is unknown. We have utilised the rat A7r5 vascular SMC line to investigate the effects of testosterone on apoptosis induced by serum deprivation or the calcium channel antagonist nifedipine.Cells were plated at 1500...

Testosterone reduces myocardial ischaemia in men with coronary artery disease (CAD) and improves symptoms and exercise capacity in men with congestive heart failure (CHF), effects proposed to be due to testosterone-induced vasodilatation. Isolated vessel studies suggest this occurs via a calcium antagonistic action upon voltage-gated Ca2+ channels but this has yet to be investigated directly.We therefore employed patch clamp methodology to stu...

Low serum testosterone levels in men predict the future development of insulin resistance and Type 2 diabetes. Furthermore, men with Type 2 diabetes have lower testosterone levels than nondiabetic men. Testosterone is known to be positively correlated with insulin sensitivity. It has also been demonstrated that low levels of circulating androgens are associated with coronary artery disease, dyslipidaemia, hypertension and visceral obesity. The purpose of this study was to dete...