Regulation of corticosterone function during early weaning and effects on gastric cell proliferation.
Nutrition. 2014-03-01; 30(3): 343-349
DOI: 10.1016/j.nut.2013.09.003
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1. Nutrition. 2014 Mar;30(3):343-9. doi: 10.1016/j.nut.2013.09.003.
Regulation of corticosterone function during early weaning and effects on gastric
cell proliferation.
Ghizoni H(1), Figueiredo PM(1), Moisan MP(2), Ogias D(1), Osaki LH(1), Gama P(3).
Author information:
(1)Department of Cell and Developmental Biology, Institute of Biomedical
Sciences, University of São Paulo, São Paulo, SP, Brazil.
(2)INRA, Nutrition et neurobiologie intégrée, UMR 1286, Bordeaux, France; Univ
Bordeaux, Nutrition et neurobiologie intégrée, UMR 1286, Bordeaux, France.
(3)Department of Cell and Developmental Biology, Institute of Biomedical
Sciences, University of São Paulo, São Paulo, SP, Brazil. Electronic address:
.
OBJECTIVES: The development of the gastrointestinal tract depends on many
elements, including glucocorticoids. In the current study, we evaluated the
effects of early weaning on corticosterone function and the growth of rat gastric
mucosa.
METHODS: By using Wistar rats submitted to early weaning at 15 d, we analyzed
plasma corticosterone, corticosteroid-binding globulin (CBG), and glucocorticoid
receptor (GR) distribution in the gastric epithelium.
RESULTS: With the use of radioimmunoassay, we found that early weaning increased
corticosterone concentration at day 16 and 17 in test subjects as compared with
controls, whereas it was equivalent between groups at day 18. CBG binding
capacity decreased during treatment, and it was significantly lower at day 18. At
this age, GR levels and distribution in the gastric mucosa were also reduced as
compared with suckling counterparts. To reduce corticosterone activity during
early weaning and to explore cell proliferation responses, we administered RU486
to 15-d-old pups. We found that cytoplasmic GR reached a peak after 48 h, whereas
nuclear levels remained constant, thereby confirming the inhibition of receptor
function. Next, by checking gastric proliferative responses, we observed that
RU486 induced higher DNA synthesis and mitotic indices in test subjects as
compared with control groups.
CONCLUSIONS: We demonstrated that early weaning changed corticosterone activity
by increasing hormone levels, reducing CBG binding capacity, and decreasing GR
distribution in the gastric epithelium. These modifications seem to be important
to the reorganization of gastric growth after the abrupt interruption of
suckling.
Copyright © 2014 Elsevier Inc. All rights reserved.
DOI: 10.1016/j.nut.2013.09.003
PMID: 24484684 [Indexed for MEDLINE]