TY - JOUR
T1 - Bombesin maintains enterocyte phenotype in fasted rats
AU - Hodin, R. A.
AU - Meng, S.
AU - Shei, A.
AU - Bass, B.
AU - Mercer, D.
AU - Rudnicki, M.
PY - 1994
Y1 - 1994
N2 - Background. Previous studies have suggested a relationship between enterocyte phenotype and the growth state of the epithelium: under atrophic conditions, lactase gene expression is high, whereas intestinal alkaline phosphatase (IAP) expression is low, and vice versa. On the basis of this model, we hypothesized that the intestinal trophic factor bombesin would alter brush-border enzyme gene expression in a predictable way. Methods. Adult rats were fasted for 18 hours and treated (intraperitoneally) with either 10 μg/kg bombesin or the saline control every 8 hours. Small intestinal mucosal scrapings were taken, total RNA purified, and Northern blot analyses performed with radiolabeled cDNA probes corresponding to lactase, IAP, villin, and actin. Tissue samples were also taken for measurement of mucosal thickness. Results. Bombesin administration caused an increase in jejunal mucosal thickness, thereby confirming its trophic effects. Bombesin resulted in a decrease in lactase mRNA levels and an increase in IAP mRNA levels along the length of the small intestine. No changes occurred in the expression of either villin or actin. The pattern of enterocyte gene expression in the bombesin-treated animals was similar to that in control-fed rats. Conclusions. Bombesin differentially regulates rat enterocyte gene expression, decreasing lactase and increasing IAP mRNA levels. These results lend further support to the hypothesis that a close relationship exists between enterocyte phenotype and epithelial growth state.
AB - Background. Previous studies have suggested a relationship between enterocyte phenotype and the growth state of the epithelium: under atrophic conditions, lactase gene expression is high, whereas intestinal alkaline phosphatase (IAP) expression is low, and vice versa. On the basis of this model, we hypothesized that the intestinal trophic factor bombesin would alter brush-border enzyme gene expression in a predictable way. Methods. Adult rats were fasted for 18 hours and treated (intraperitoneally) with either 10 μg/kg bombesin or the saline control every 8 hours. Small intestinal mucosal scrapings were taken, total RNA purified, and Northern blot analyses performed with radiolabeled cDNA probes corresponding to lactase, IAP, villin, and actin. Tissue samples were also taken for measurement of mucosal thickness. Results. Bombesin administration caused an increase in jejunal mucosal thickness, thereby confirming its trophic effects. Bombesin resulted in a decrease in lactase mRNA levels and an increase in IAP mRNA levels along the length of the small intestine. No changes occurred in the expression of either villin or actin. The pattern of enterocyte gene expression in the bombesin-treated animals was similar to that in control-fed rats. Conclusions. Bombesin differentially regulates rat enterocyte gene expression, decreasing lactase and increasing IAP mRNA levels. These results lend further support to the hypothesis that a close relationship exists between enterocyte phenotype and epithelial growth state.
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M3 - Article
C2 - 8048008
AN - SCOPUS:0028033616
VL - 116
SP - 426
EP - 431
JO - Surgery (United States)
JF - Surgery (United States)
SN - 0039-6060
IS - 2
ER -