[Preparation and identification of polyclonal antiserum against angiotensinogen]

For studying the expression and distribution of angiotensinogen (AGT), the C-teminus of rat AGT gene was expressed in E.coli. Rabbits were immunized with expressed AGT protein and sera from different rabbits were raised. ELISA showed a high titre (1:25600) of the antiserum. With the antiserum, Western blotting recognized not only the prokaryotic expressed AGT, but also the endogenous AGT protein in liver tissue of both rats and humans. Using this antiserum, immunohistochemistry showed the expression of AGT protein in islet cells of human pancreas as well as in epithelium of human bile duct. These results suggest that the prokaryotic expressed AGT protein is an effective immunogen for the preparation of anti-AGT antiserum. Our present work provides an important tool for study of the pathophysiological role of AGT as well as local renin-angiotensin system.