Endocrine Abstracts

The global epidemic of obesity has heightened the need to understand the mechanisms that underpin its pathogenesis. Clinical observations in patients with Cushing's syndrome have highlighted the link between cortisol and central obesity. However, whilst circulating cortisol levels are normal or reduced in obesity, local regeneration of cortisol, from inactive cortisone, by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) has been postulated as a pathogenic mechanism. W...

Radioidine (RI) has been implicated as an adverse factor causing deterioration of Thyroid-Associated Ophthalmopathy (TAO). Oral steroids administered after RI appear to protect patients' eyes, and this practice is now widespread. Two factors may confound the controversy surrounding the effects of RI on TAO. Firstly hypothyroidism, which is common after RI and is independently detrimental to the eyes, and secondly studying patients who are in different phases of the natural his...

IntroductionWe have previously demonstrated profound effects of hormone replacement treatment (HRT) in post-menopausal women on the IGF-system. HRT is widely used to prevent osteoporosis. The IGF-system has been implicated in bone formation. IGFBP-4 and IGFBP-5 are known to be important in modulation of IGF activity in bone. In this larger study we have examined the effects of HRT on circulating IGFBP-4 levels.MethodOral conjugated equine estrogen (CEE) alone or in...

In humans the most abundant source of 11 beta-hydroxysteroid dehydrogenase type 2 is the placenta, notably placental trophoblast. This enzyme catalyses the conversion of cortisol (F) to cortisone (E) and is thought to protect the fetus from maternal hypercortisolaemia, thereby impacting on fetal growth and development. During gestation placental trophoblast is exposed to dramatic changes in oxygen tensions ranging from ~2% - 12%, changes thought to be pivotal in stimulating an...

Background. The GH/IGF-I axis has been implicated in the pathogenesis of colon and breast cancer. We have recently demonstrated that the local expression of its components correlates with that of tumour-associated genes and angiogenesis. The two predominant isomers of GH in humans are 22kDa and 20kDa isomers. A recent study reported that the two isomers exert opposing effects on breast cancer cells: 22kDa GH promotes proliferation whereas 20kDa GH inhibits proliferation. The l...

Paragangliomas are rare tumours that arise from extra-adrenal chromaffin cells within the sympathetic paraganglionic axis. While neoplasms of the adrenal medulla, (phaeochromocytomas) are normally characterized by catecholamine (CA) hypersecretion, paragangliomas can be nonfunctional. We report our findings from 5 patients (4 males, 1 female) with paragangliomas. In 4 out of 5 patients the initial presentation was related to the space-occupying effect of the tumour. Episodic s...

11 beta-hydroxysteroid dehydrogenase type 2 (11 beta-HSD2) is responsible for the conversion of hormonally active cortisol (F) to inactive cortisone (E), and is expressed in mineralocorticoid target tissues (kidney, colon). However, the most abundant source of this enzyme is human placenta, notably placental trophoblast where it is thought to protect the fetus from maternal hypercortisolaemia and play a role in fetal growth and development. During gestation placental trophobla...

Our recent studies have localised 11 beta hydroxysteroid dehydrogenase type 1 (11 beta HSD1), which activates cortisol from cortisone, to the human ocular non-pigmented ciliary epithelium, and in an open blinded study conducted on healthy male volunteers, systemic inhibition of this isozyme with oral carbenoxolone (CBX) resulted in a 17% reduction of intraocular pressure (IOP). The aim of this study was to evaluate whether CBX reduced IOP in patients with ocular hypertension (...

BACKGROUND: We have previously shown that men with coronary artery disease (CAD) have lower serum bioavailable testosterone levels than men with normal coronary arteries and this may have detrimental effects in coronary disease. It has been suggested that low androgen levels in men with CAD could be accounted for by the high prevalence of statin therapy and other factors such as smoking. We investigated the effects of statin therapy and smoking on testosterone in men with CAD....

BACKGROUND: Previous work has demonstrated a relationship between impaired carbohydrate metabolism and low serum levels of androgens in men. Men with diabetes have lower testosterone levels, and administration of physiological doses of testosterone improves glucose tolerance in these men. Men with coronary artery disease (CAD) have lower androgen levels than men with normal coronary arteries. We studied the relationship between testosterone, glucose, hypertension and DM in a p...