Abstract: ObjectiveTo explore the effects of Tongxinluo on myocardial fibrosis of rats with spontaneous hypertension. Methods16 eight-week-old male rats with spontaneous hypertension (SHRs) were divided at random into two groups: the Tongxinluo group (n=8, 1.5mg·kg^-1·d^-1) and the SHR group(n=8). Another 8 eight-week-old male Wistar Kyoto rats served as the control group. 12 weeks later, the ratio of early to late mitral flow, the ratio of early to late mitral annulus velocity (E/A and Ea/Aa), the deceleration time of the E wave (DTe), the left ventricular isovolumic relaxation time (IVRT), the average image intensity (AII), the corrected acoustic intensity (CAI) and the peak to peak intensity (PPI) of the interventricular septum and the left ventricular posterior wall were all determined by cardiography. Results① The diastolic indexes E/A and Ea/Aa in the Tongxinluo group were SHR group(P＜0.05), but were significantly lower than those in the normal control group (P<0.05); the diastolic indexes DTe and IVRT in the Tongxinluo group were significantly higher than those in the SHR group (P＜0.05), but were significantly lower than those in the control group (P＜0.05). ② AII and CAI of the inter-ventricular septum and the left ventricular posterior wall in the Tongxinluo group were significantly lower than those in the SHR group, but PPI of the inter-ventricular septum and the left ventricular posterior wall was significantly higher than that in the SHR group (P＜0.05); AII and CAI of the interventricular septum and the left ventricular posterior wall in the control group were significantly lower than those in the Tongxinluo group, but PPI of the inter-ventricular septum and the left ventricular posterior wall was significantly higher than that in the Tongxinluo group (P＜0.05). Conclusion Tongxinluo capsule can reduce myocardial fibrosis caused by overload and improves the left ventricular diastolic dysfunction induced by hypertension.

Key words: Fibrosis, Rats Inbred SHR, Tongxinluo, Hypertension