OBJECTIVE
To determine the expressions of angiotensin-converting enzyme 2 (ACE2) in spontaneously hypertensive rats and the effect of apigenin.
METHODS
Sixty male SHR rats aged 12 weeks were randomly divided into 6 groups based on body weight and blood pressure. The rats in a normal control group and 4 experimental groups were given 0, 0.007, 0.026, 0.104 and 0.417 g/kg of apigenin respectively, and the rats in positive control group were given 12 mL/kg captopril. Systolic blood pressure (SBP) and heart rate were measured once a week; body weight was measured twice a week. At the end of the experiment, the expression of ACE2 mRNA was determined by real time PCR and the distribution and expression of ACE2 in kidney was determined by immunohistochemistry. SBP was measured by tail-cuff method.
RESULTS
The transcription level of ACE2 mRNA in captopril positive control group and 0.417 g/kg bw apigenin group was significantly higher than the control group (P < 0.05). The immunohistochemistry results were consistent with the gene expression results.
CONCLUSION
The effect of apigenin on lowering blood pressure was related to up-regulating the expression of ACE2 in kidney. However, further study is still needed for the possible mechanisms.