Fasting differentially regulates plasma corticosterone-binding globulin, glucocorticoid receptor, and cell cycle in the gastric mucosa of pups and adult rats.
American Journal of Physiology-Gastrointestinal and Liver Physiology. 2010-01-01; 298(1): G117-G125
DOI: 10.1152/ajpgi.00245.2009
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1. Am J Physiol Gastrointest Liver Physiol. 2010 Jan;298(1):G117-25. doi:
10.1152/ajpgi.00245.2009. Epub 2009 Oct 15.
Fasting differentially regulates plasma corticosterone-binding globulin,
glucocorticoid receptor, and cell cycle in the gastric mucosa of pups and adult
rats.
Ogias D(1), de Andrade Sá ER, Kasai A, Moisan MP, Alvares EP, Gama P.
Author information:
(1)Department of Cell and Developmental Biology, Institute of Biomedical
Sciences, University of São Paulo, São Paulo, Brazil.
The nutritional status influences gastric growth, and interestingly, whereas cell
proliferation is stimulated by fasting in suckling rats, it is inhibited in adult
animals. Corticosterone takes part in the mechanisms that govern development, and
its effects are regulated in particular by corticosterone-binding globulin (CBG)
and glucocorticoid receptor (GR). To investigate whether corticosterone activity
responds to fasting and how possible changes might control gastric epithelial
cell cycle, we evaluated different parameters during the progression of fasting
in 18- and 40-day-old rats. Food restriction induced higher corticosterone plasma
concentration at both ages, but only in pups did CBG binding increase after
short- and long-term treatments. Fasting also increased gastric GR at
transcriptional and protein levels, but the effect was more pronounced in
40-day-old animals. Moreover, in pups, GR was observed in the cytoplasm, whereas,
in adults, it accumulated in the nucleus after the onset of fasting. Heat shock
protein (HSP) 70 and HSP 90 were differentially regulated and might contribute to
the stability of GR and to the high cytoplasmic levels in pups and elevated
shuttling in adult rats. As for gastric epithelial cell cycle, whereas cyclin D1
and p21 increased during fasting in pups, in adults, cyclin E slowly decreased,
concomitant with higher p27. In summary, we demonstrated that corticosterone
function is differentially regulated by fasting in 18- and 40-day-old rats, and
such variation might attenuate any possible suppressive effects during postnatal
development. We suggest that this mechanism could ultimately increase cell
proliferation and allow regular gastric growth during adverse nutritional
conditions.
DOI: 10.1152/ajpgi.00245.2009
PMID: 19833863 [Indexed for MEDLINE]