Abstract:

Objective  To investigate the relationship of ACE2 and blood pressure on expression levels of mRNA and protein in spontaneously hypertensive rats(SHR).  Methods  18 male (12 weeks old) SHRs and 18 male (12 weeks old) Wistar Kyoto(WKY) rats were randomly divided into two groups: the WKYcontrol group(n=18) and the SHR group(n=18). Nine SHRs and nine WKY rats were randomly drawn for detection. After 12 weeks feeding,  other rats were executed for detection. The mRNA expression of ACE2 was determined by real-time quantitative RT-PCR and the protein level of ACE2 by immunohistochemistry.   Results   (1) SBP in the 12-and 24- weeks old SHR groups was increased compared with that in the WKY group (all P＜0.001). SBP in the 24-weeks old SHR group was increased compared with that in the 12-week old SHR group (P＜0.01). (2) Expression of ACE2 mRNA in the 12-and 24-weeks old SHR groups was significantly lower than that in the WKY group (all P＜0.001) and in the 24-weeks old SHR group was significantly lower than that in the 12-weeks old SHR group (P＜0.01). (3) Immunohistochemistry showed that positive reaction of ACE2 protein was all stained brown and found in the kidneys. ACE2 had a uniform distribution of thick brown granules in the WKY group and a comparatively rare distribution by brown granules in the SHR group.  Conclusion There are correlations between the renal expressions of mRNA and protein ACE2 and blood pressure.

Key words: Angiotensin converting enzyme 2; Spontaneously hypertensive; Rat; Kidney; Hypertension