Endocrine Abstracts

The predominant positive and negative regulators of skeletal muscle mass are IGF1 and myostatin respectively. The regulation of skeletal muscle mass, IGF1 and myostatin by the gonadal steroids testosterone and 17β-oestradiol (E2) remains controversial. Male and female C57BL/6 mice underwent bilateral gonadectomy or sham surgery at 4 weeks of age, with insertion of s.c. silastic implants containing testosterone, E2, or cholesterol (placebo) (n</em...

GH regulates IGF1 predominantly through the intracellular signallers Stat5a and Stat5b. Inactivating mutations of Stat5b in humans result in severe growth retardation and low circulating IGF1 concentrations in males and females. In mice, however, there is only a loss of sexually dimorphic growth in males when Stat5b is deleted. No study has observed Stat5b−/− mice beyond 12 weeks or investigated any subsequent changes in skeletal muscle mass or IGF1 expr...

Introduction: Male hypogonadism is one of the most common endocrine disorders affecting 5.6% of men aged between 30–79 years. Testosterone deficiency (TD) is an independent risk factor for multiple cardiovascular risk factors including obesity, diabetes mellitus, hypertension, dyslipidaemia and endothelial dysfunction. The aims of testosterone replacement treatment (TRT) in hypogonadism are to improve or ameliorate the clinical features and to restore the serum T to physi...