Endocrine Abstracts

The angiotensin II type 1 receptor (AT1R) belongs to the family of seven trans-membrane (7TM) receptors, also referred to as G-protein coupled receptors. The AT1R is the primary effector of the renin–angiotensin system, and serves as a key regulator of cardiovascular physiology. The importance of the receptor is clearly illustrated be the frequent use of AT1R blockers and ACE inhibitors in cardiovascular medicine. Upon binding of Ang II th...

Introduction: There are many reports that vascular and/or heart valve calcification is good predictor for low bone mineral density. I investigated whether benign calcification of breast can also well predict low bone mineral density.Methods/design: I have reviewed and analyzed the records of 91 women with age more than 50 years old among patients examined bone mineral density and breast mammography from January through December 2010. The lowest value of ...

The classical genomic actions of triiodothyronine (T3) are mediated by high-affinity nuclear receptors that directly regulate gene expression. By contrast, the non-genomic effects of thyroid hormones occur rapidly and are unaffected by inhibitors of transcription and protein synthesis. The genomic actions of thyroid hormone have an established role in the development, differentiation and homeostatic maintenance of target tissues. The THRA and THRB gene...

Disruption of the HPT-axis during growth profoundly influences skeletal development and effects may not be reversed fully following correction of thyroid status. Adult thyrotoxicosis leads to increased bone turnover and is an established risk factor for osteoporotic fracture. The conventional view that skeletal responses to abnormal thyroid status result solely from altered T3 action in bone has, however, been questioned by studies proposing TSH as a negative regula...

The standard technique for the functional imaging of pheochromocytoma and paraganglioma (PPGL) is [123I]-metaiodobenzylguanidine single photon emission computed tomography (MIBG SPECT). However, metastases are more accurately detected by 2-[18F]-Fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET). In a large prospective study of 216 patients evaluated at the NIH for benign or malignant PPGL, we investigated the sensitivity and specificity of FDG PET ...

Thyrotoxicosis results in osteoporosis and thyroid hormone (T3) stimulates osteoclastic bone resorption by unknown mechanisms. We previously demonstrated that knockout mice lacking thyroid hormone receptor α (TRα0/0) are euthyroid but have high bone mass, whereas mice lacking TRβ (TRβ−/−) are thyrotoxic and have osteoporosis. Tartrate resistant acid phosphatase (TRAcP) staining revealed osteoclast numbers were re...

Thyroid hormones regulate adult bone turnover. Thyrotoxicosis results in high turnover osteoporosis whilst hypothyroidism leads to low bone turnover with increased bone mass and mineralisation. T3-target tissues express thyroid hormone receptor alpha (TRα), thyroid hormone receptor beta (TRβ)or both receptors. TRα1 mediates the actions of T3 in bone and in skeletal cells TRα1 mRNA expression is 12-fold higher than TRβ1. Accordingl...

Local regulation of T3 action in bone and cartilage is a novel mechanism underlying the pathogenesis of osteoarthritis (OA). Accelerated chondrocyte differentiation is a hallmark of OA and T3 regulates this process. The type 1 and 2 deiodinases (D1, D2) convert the pro-hormone T4 to the active hormone T3 whilst D3 inactivates both T3 and T4. D1 contributes to circulating T3 levels and local T3</s...

Articular cartilage maintenance and repair is regulated by numerous endocrine and paracrine factors. Investigation of molecular mechanisms underlying osteoarthritis (OA) is limited by inability to identify early stage disease and individuals at risk of progression. Susceptibility to OA is genetically determined and the availability of mice from the International Knockout Mouse Consortium with deletions of every known gene provides a unique opportunity to investigate its pathop...

Background: Hypogonadism is a major feature of Prader–Willi syndrome, but clinical manifestations are variable. Sexual interests and behavior in this population have not been previously described.Objectives: We studied PWS adolescents and young adults to assess: i) satisfaction with physical and sexual development ii) frequency of romantic and sexual experiences, iii) aspirations and expectations regarding marriage, iv) investigate the relation betw...