Serum glucose and insulin response in rats administered with sucrose or starch containing adenosine, inosine or cytosine

Blood glucose and insulin responses and gastric emptying were examined in r ats intubated with sucrose or soluble starch that contained adenosine, inos ine and cytosine. The increase in serum glucose and insulin levels in the rats following load ing with sucrose (2.5 g/kg of body weight) or soluble starch (1.875 g/kg of body weight) was significantly reduced by the administration of adenosine, inosine and cytosine (0.0625-0.125 g/kg of body weight). The gastric emptying rates were only marginally affected by the nucleoside administration. The activities of sucrase, maltase, isomaltase and glucoamy lase in a crude preparation from the small intestinal mucosa of rats were m ildly inhibited by the nucleosides. The decrease in blood glucose and insulin levels may have been in response to a decrease in glucose absorption caused by the inhibiting effect of the nucleosides on the mucosal enzymes that digest sucrose, maltose, and malto- and isomalto-oligosaccharides.