Endocrine Abstracts

The incidence of type 2 diabetes (T2DM) has doubled over the past decade. Obesity induced insulin resistance is associated with T2DM and the metabolic syndrome (including hypertension, and dyslipidemia). Diets high in saturated fat are largely to blame for the current obesity epidemic. High-fat feeding of animals increases circulating corticosterone levels, in addition to changes in glucose homeostasis. The relationship between insulin sensitivity and abnormal hypothalamic&#15...

The prevalence of obesity and its association with many health complications have evoked a high interest in adipose tissue metabolism. In man, glucocorticoid (GC) excess increases fat mass and the risk of developing Metabolic Syndrome. The enzyme responsible for modifying intracellular GC concentrations in adipose tissue is 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). The aim of this study was to characterise the novel human preadipocyte cell line (Chub-S7) an...

To dissect mechanisms which result in 1,25 dihydroxyvitamin D3 (1,25(OH)2D3) insensitivity we have compared the antiproliferative actions of 1,25(OH)2D3 in a range of malignant breast cell lines (ZR-75-1, T-47D, MCF-7, MCF-7Res and MDA-MB-231) and the non-malignant breast epithelial cells MCF-12A cells. All the malignant cell lines displayed greater resistance than MCF-12A cells to 1,25(OH)2D3. For ex...

Dehydroepiandrosterone (DHEA) is the crucial androgen precursor and hyperandrogenaemia is a major feature in Polycystic Ovary Syndrome (PCOS). DHEA sulfate (DHEAS) is generated from DHEA by DHEA sulfotransferase (SULT2A1) activity. The conversion of DHEAS to DHEA by steroid sulfatase has been reported to be of minor significance in human adults and only desulfated DHEA can be converted toward androgens. Therefore, SULT2A1 activity represents the rate-limiting step regulating t...

Acute inflammation plays an important role in the normal immune system by helping to coordinate host responses to danger signals such as infection. In most cases the inflammation is rapidly resolved but in chronic inflammatory diseases such as rheumatoid arthritis (RA) the inflammation persists leading to localized accumulation of potentially damaging immune cells. It remains unclear why inflammation persists in some tissues and not in others. Recent studies have shown that st...

Childhood obesity is increasing in prevalence and is associated with insulin resistance and Type II diabetes in later life. Site-specific differences in adipose tissue accumulation and associated insulin sensitivity may contribute to these problems.The aims of our study were: 1. To isolate and characterise, subcutaneous (SC) and visceral (V) preadipocytes using small biopsies from pre-pubertal children (ages:4-8years(n=3)) undergoing elective abdominal surgery, with normal...

Fibroblasts are important regulators of local inflammatory responses. These responses are further regulated by tissue glucocorticoid levels. Other stromal lineage cells, adipocytes and osteoblasts, express 11beta-hydroxysteroid dehydrogenases (11b-HSDs) which interconvert inactive cortisone and active cortisol. These enzymes are important regulators of local glucocorticoid levels and their expression is regulated by proinflammatory cytokines. We therefore examined expression o...

Patients with obesity are relatively Growth Hormone (GH) deficient. GH has potent effects on adipocyte biology, stimulating lipolysis but also promoting pre-adipocyte proliferation. Conversely, we have shown that cortisol inhibits pre-adipocyte proliferation and enhances differentiation. Furthermore, GH, acting through IGF-1, inhibits 11 beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) which converts the inactive glucocorticoid, cortisone (E) to active cortisol (F) in ad...

Within the synovium of patients with rheumatoid arthritis (RA), synovial fibroblasts generate active corticosteroids through expression of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). In vitro, this enzyme is strongly up-regulated by pro-inflammatory cytokines such as tumour necrosis factor α (TNFα) and IL1β. In this study, we determined the relationship between inflammation and global 11β-HSD1 activity in vivo, in a clini...

Mitotane (o,p’DDD) is commonly used for the treatment of adrenocortical carcinoma (ACC), both for advanced disease and in the adjuvant setting. Mitotane induces adrenal insufficiency but specific effects on steroidogenic enzymes are unknown.We investigated 24-h urinary steroid metabolite excretion in ACC patients on adjuvant mitotane (AD) or mitotane for metastatic disease (MET). We compared samples collected before mitotane treatment (BEFORE; MET <...