AIMTo study the plasma angiotensin II (Ang II) levels and the expressions of angiotensin II1 receptor (AT1) in blood vessels and kidneys in diabetic and high fat diet rats, and the effects of enalapril on plasma Ang II levels and the expressions of AT1 in blood vessels and kidneys in diabetic rats.

METHODSThe plasma Ang II level was assayed with 125I-Ang II radioimmunoassay, and the expression of AT1 in blood vessel and kidney was analyzed with immunohistochemical technique.

RESULTSThe plasma Ang II level was significantly higher in type 2 diabetic rats (241 +/- 49) pg x mL(-1) than that in the control (71 +/- 22) pg x mL , high fat diet group (151 +/- 29) pg x mL(-1) (P < 0.01) , and enalapril-treated groups (136 +/- 25) pg x mL(-1) (P < 0.05). The plasma Ang II levels in high fat diet and in enalapril-treated groups were also significantly higher than that in control group ( P < 0.01 ). With immunohistochemical technique, it was found that the expression of AT1 in endothelial cells of blood vessels, vascular smooth muscle cells, and kidneys in diabetic group increased. The expression of AT1 in endothelial cells of blood vessels, vascular smooth muscle cells, and kidney in enalapril-treated group was similar to that in control group.

CONCLUSIONThe plasma Ang II levels and the expression of AT1 in type 2 diabetic and high fat diet rats increased. Enalapril was shown to decrease the plasma Ang II level and downregulate the expression of AT1 in blood vessels and kidneys in type 2 diabetic rats.