ABSTRACT
Objective To investigate the expression of angiotensin-converting enzyme 2(ACE2) protein and mRNA in kidney of different age spontaneously hypertensive rats(SHR) and the role of ACE2 in the development of hypertension. Methods Male SHR(n=30) were allocated to 5 groups by age: 1)one-month-old group(S1); 2)two-month-old group(S2); 3)three-month-old group(S3); 4)six-month-old group(S6); 5)nine-month-old group(S9). Sex and age matched Wistar-Kyoto normotensive rats(WKY)served as controls. The expression of ACE2 mRNA in kidney was determined by reverse transcription polymerase chain reaction(RT-PCR). The expression of ACE2 protein in kidney was assessed by immunohistochemistry and computer image analysis. Results 1)An age-dependent increase of SBP was observed in SHR before six months(P0.05). 2)An age-dependent increase of the ACE2 protein and mRNA levels in kidney was observed in both SHR and WKY(P0.05). The ACE2 protein and mRNA levels in kidney were lower in SHR than those in the matched WKY at every corresponding time point(P