Aim To study the plasma angiotensin II (Ang II) levels and the expressions of angiotensin II 1 receptor (AT 1 ) in
blood vessels and kidneys in diabetic and high fat diet rats, and the effec ts of enalapril on plasma Ang II levels and the expressions of AT 1 in bloo d vessels and kidneys in diabetic rats. Methods The plasma Ang II level was assayed with 125I-An g II radioimmunoassay, and the
expression of AT 1 in blood vessel and kidne y was analyzed with immunohistochemical technique. Results The plasma Ang II level was significantly higher in type 2 diabetic rats (241±49) pg·mL -1 than that in the control (71±22) pg·mL -1, high fat diet group (151±29) pg·mL -1 ( P<0 .01), and enalapril-treated groups (136±25) pg·mL -1 ( P<0. 05). The plasma Ang II levels in high fat diet and in enalapril-treated group s were also significantly higher than that in control group ( P<0.01). W ith immunohistochemical technique, it was found that the expression of AT 1 in endothelial cells of blood vessels, vascular smooth muscle cells, and kidney s in diabetic group increased. The expression of AT 1 in endothelial cells of blood vessels, vascular smooth muscle cells, and kidney in enalapril-treated group was similar to that in control group. Conclusion The plasma Ang II levels and the expression of AT 1 in type 2 diabetic and high fat diet rats increased. Enalapril was shown t o decrease the plasma Ang II level and downregulate the expression of AT 1 in blood vessels and kidneys in
type 2 diabetic rats.