Endocrine Abstracts

The physiological effects of the pituitary hormone, adrenocorticotropic hormone (ACTH) on the adrenal are mediated by the melanocortin 2 receptor (MC2R), a G protein coupled receptor (GPCR) that signals via adenylate cyclase to elevate intracellular cyclic AMP (cAMP) levels. Therefore the expression and function of the receptor are likely to be the major determinants of the response to ACTH. Following repeated stimulation, the cAMP signal is diminished or desensitised. Desensi...

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...

Pseudoexons resemble true exons by current bioinformatic criteria and may outnumber true exons by 10:1. They are, however, never spliced into mature mRNA. A point mutation in the GHR gene results in abnormal splicing of a pseudoexon, leading to Laron syndrome. The GHR pseudoexon lies between exons six and seven and the point mutation is adjacent to the pseudoexon 5' splice site.Our studies aimed to define the elements that normally prevent splicing of this pseudoexon.A...

Low birth weight infants have higher mortality rates and are at a greater risk of impaired immunity in later life than are their normal-birth-weight counterparts. The aim was to investigate the effect of maternal dietary fat supplementation during the first or second half of gestation on the plasma immunoglobulin A concentration in her offspring.Six pregnant sows were randomly allocated to receive 10% extra energy derived from dietary fat during either t...

Studies on the lipid emulsion for total parenteral nutrition (TPN) for the premature human infant are limited. We investigated the effects of modifying the fatty acid composition of TPN on the growth and development of the preterm piglet.Piglets delivered by Caesarean section on day 112 of gestation (term = 115 days) received an enteral diet (E: n=6) or TPN solution plus Intralipid (54% 18:2, 25% 18:1; I: n=6) or ClinOleic (17% 18:2, 65% 18:1; C: n=6) fo...