Expression and localization of the renin-angiotensin system in the rat pancreas

The possibility of an intrinsic renin-angiotensin system (RAS) in the pancr eas has been raised by previous studies in which immunohistochemical examin ation showed the presence of angiotensin II and its receptor subtypes, type 1 (AT(1)) and type 2 (AT(2)). In the present study, gene expression of sev eral key RAS components was investigated by reverse-transcription PCR. mRNA expression for angiotensinogen, renin and angiotensin II receptor subtypes , AT(1a), AT(1b) and AT(2) was shown. The presence of angiotensinogen prote in, the mandatory component for an intrinsic RAS, was demonstrated by Weste rn blotting and localized by immunohistochemistry to the epithelia and endo thelia of pancreatic ducts and blood Vessels respectively. Immunoblot analy sis detected a predominant protein band of about 60 kDa in the pancreas. Th is was consistent with the predicted value for angotensinogen as reported i n other tissues. Together with previous findings, the present study shows t hat the rat pancreas expresses the major RAS component genes, notably angio tensinogen and renin, required for intracellular formation of angiotensin I I. The data support the notion of an intrinsic RAS in the rat pancreas whic h may play a role in the regulation of pancreatic functions.