CALORIC RESTRICTION CAUSES SECRETAGOGUE SPECIFIC CHANGES OF GASTRIC-ACID SECRETION IN RATS

The purpose of this study was to examine the effects of short-term cal oric restriction (CR) for 4, 8 and 16 weeks on gastric acid secretion in rats. CR rats were fed 60% of normal food intake for 4, 8 or 16 wee ks and then prepared with gastric fistulas. Histamine- and carbachol-s timulated gastric acid secretion were significantly (P < 0.05) decreas ed after more than 4 weeks and 8 weeks of caloric restriction, respect ively. In contrast, gastrin-stimulated acid secretion was unaffected b y CR. The l-h-integrated acid output to a submaximal dose of gastrin ( 40 mu g . kg(-1)) was significantly higher than that of histamine (5 m g . kg(-1)) after 8 weeks of CR (63+/-13 and 27+/-4 mu Eq . h(-1), res pectively). Gastrin treatment (5 mu g . kg(-1). h(-1)) of CR rats rest ored the gastric acid responses to both histamine and carbachol. These results suggest that CR can selectively decrease the gastric acid res ponses to both histamine and carbachol by depletion of the endogenous tissue stores of gastrin. More importantly, these results indicate tha t under an in vivo gastrin-diminished condition, histamine is not the final secretagogue for gastric acid secretion. (C) 1997 Elsevier Scien ce B.V.