Endocrine Abstracts

Expression of the ACTH receptor, MC2-R, is highly restricted, being detectable in the mouse only in the adrenal cortex and adipose tissue. The promoter of the murine MC2-R contains binding sites for SF-1, a transcription factor that has been shown to be essential for the transcriptional activity of a number of steroidogenic genes. However, SF-1 is not expressed in adipocytes and therefore is not essential for MC2-R expression in these cells. We have investigated the requiremen...

A 20 year of man with cerebral palsy (spastic diplegia and mild learning difficulties) initially presented to the neurologists with a 4 month history of deterioration in mobility and new difficulties in speech, swallowing and incontinence of urine. New proximal muscle weakness, dyskinesia and ataxia were noted bilaterally in all limbs, Myoclonic jerks and absence seizures were also seen. His swallowing deteriorated to the point where 'PEG' feeding was necessary. Exhaustive neu...

The murine ACTH receptor MC2-R is primarily expressed in the adrenal cortex and adipocytes where it binds ACTH leading to steroidogenesis and lipolysis, respectively. We have recently shown that the previously described 'adrenal' MC2-R promoter is transiently activated by PPAR gamma 2 early during differentiation of murine 3T3-L1 pre-adipocytes, declining to background levels from a peak of activity seen at day 4 following commencement of adipogenesis. This is mirrored by the ...

The peptide hormone ACTH can stimulate lipolysis and suppress leptin expression in murine adipocytes. These effects are mediated via the Melanocortin 2 Receptor (MC2-R), which is expressed when 3T3-L1 cells are induced to differentiate into adipocytes. In this study we have investigated the transcriptional activation of the MC2-R gene during adipogenesis.5' deletion analysis of the murine MC2-R promoter revealed the presence of a transcriptional enhancer...

The Melanocortin 2 Receptor (MC2R) is best known for its role in the adrenal cortex where it couples the action of ACTH to steroidogenesis, however it is also expressed by the adipocyte. We set out to characterize the up-regulation of the MC2R in the 3T3-L1 fibroblast, which can be induced to undergo adipogenesis.RT-PCR using primers specific to exons 1 and 2 amplified three bands in differentiated 3T3-L1 adipocytes which sequencing revealed to be distin...

Ectopic secretion of adrenocorticotropin (ACTH), from sites such as small cell lung cancer (SCLC), results in severe Cushing's syndrome. ACTH is cleaved from pro-opiomelanocortin (POMC). The syndrome occurs when the highly tissue-specific promoter of POMC is activated. This promoter lies within a defined CpG island. CpG islands are usually considered to be unmethylated in all tissues. We hypothesised that changes in promoter DNA methylation might direct aberrant express...

Mediastinal location of a functional parathyroid adenoma is a rare but a well recognised entity and Tc-99M sestamibi scan is an established imaging technique for the succesful localization of such tissues with a sensitivity and specificity of more than 90%. Here we report an unusual case of primary hyperparathyroidism presenting with a 3-cm mediastinal mass with no evidence of abnormal uptake of the isotope and subsequent resolution of the mass on further imaging.<p class...

A 77 year old lady was referred by her GP after she was found to have a 6x5x5 cm diameter solid mass in the right adrenal gland on ultrasound scan. The mass showed significant internal vascularity on colour doppler and the radiologist felt it could be aphaeochromocytoma. She had a long history of hypertension which her GP had been finding difficult to control over the past 2 years.Type 2 diabetes was diagnosed 2 years ago and she...

It is well established that catecholamines have potent actions on adrenocortical function and steroidogenesis in different species. The effect of these substances on steroid production of the human adrenal cell line H295R is the subject of this study. H295R is the first adrenocortical cell line capable of secreting the normal range of adrenal steroid products (i.e. mineralocorticoids, glucocorticoids and adrenal androgens) and since free of chromaffin cells, it appears to be a...

In cases of ret-oncogene positive Medullary Thyroid Carcinoma (MTC), national guidelines advocate screening of 1st degree relatives with the Pentagastrin Stimulation Test (PST) to identify those with C-cell hyperplasia, and therefore at risk of MTC. Prophylactic thyroidectomy is recommended in those with positive tests. We highlight the difficulties of quantifying risk in the relatives of a ret-negative patient.A 30 year-old man presented with a tender n...