Effects of puerarin on blood pressure and plasma renin activity in spontaneously hypertensive rats

Puerarin is an isoflavone compound isolated from Pueraria Labate (Willd). It was proved that puerarin dilated coronary artery. It possesses adrenergic (3-receptor blocking action in our former work. In this paper. we studied further the effects of puerarin on blood pressure (BP) and plasma renin activity (PRA) in spontaneously hypertensive rats (SHR). The results showed that: 1). Puerarin 100 mg/kg ip in conscious SHR caused a reduction of BP 15% (from 24.5土1.9 t0 20.8+2.2 kPa ). decrease of heart rate (HR) 1.9% (from 485+23 t0 393+18 beats/min). These changes did not occur in normal Wistar rats. 2).Propranolol raised the BP in SHR in comparison with the depressor action of puerarin. The influence on HR was similar to puerarin. 3). In SHR, the PRA was reduced 67% from 2.18+0.45 to 0.73+0.20 ng/(ml.h) by puerarin. This phenomenon was also seen in normal Wistar rats. but not so obvious as in SHR. It suggested that puerarin decreases BP, HR, and PRA in SHR by blocking the (3-adrenergic receptors.