Abstract: Oxyntomodulin(OM)consists of glucagon and KA8 peptide. We have demonstrated that KA8 peptide administrated by intravenous infusion could inhibite the secretion of gastric acid.Now OM and KA8 peptide were given by iv infusion or icv to rats to observe the effects on blood sugar regulation and the secretion of gastric acid. As compared with control group, we found that 1. Neither iv OM nor iv KA8 peptide had no effect on the concentration of blood sugar, insulin and glucagon. 2. The raise of blood sugar and decline of insulin concentration were observed when OM but not KA8 peptide given by icv(lug). 3. No effect was found on the secretion of gastric acid offten when OM and KA8 peptide was given via icv. Based on these results, we conclude that KA8 had the effect on the secretion of gastric acid with peripheral administration. While no effect was observed with KA8 and OM given into cerebral ventricles. There was no effect on blood sugar regulating hormone with KA8 and OM administered peripheraly, while OM may elevate the blood sugar when given into cerebral ventricles.

Key words: oxytomedulin, KA8, gastric acid, blood sugar