RESUMEN
<p><b>OBJECTIVE</b>To observe the effects of phlegm-dispelling and blood stasis-resolving traditional Chinese drugs on the cell cycle of cardiac myocytes and left ventricular reconstruction in hypertensive rats.</p><p><b>METHODS</b>Bilateral renal artery stenosis was conducted to induce hypertension in rats, which were randomly divided into hypertensive model group (n = 10), sham-operated group (n = 8), high-dose drug group (n = 11) and low-dose drug group (n = 11), with 8 normal untreated rats as the normal control group. The systolic blood pressure (SBP) was measured in the tail artery of the rats. Two months after the operation, the left ventricular mass (LVM) and LVM index (LVI) were calculated in all the rats. The cell cycle changes in the left ventricular cardiac myocytes were evaluated using flow cytometry.</p><p><b>RESULTS</b>The mean blood pressure and LVI of the hypertensive model group were significantly higher than those of the normal control (P < 0.05) and sham-operated group (P < 0.01). After treatment with preparation of the traditional Chinese drugs at either high or low dose, the mean blood pressure and LVM of the rats showed obvious reduction, and LVI was decreased significantly compared with that of the model group (P < 0.05). Compared with the hypertensive model group which showed obviously decreased cell percentage in G0/G1 phase and increased S phase cells, the treatment at both doses significantly increased the cells in G0/G1 phase (P < 0.05) and decreased the S-phase cells (P < 0.05) to levels comparable to those in the normal control and sham-operated groups (P > 0.05). The percentage of G2/M-phase cells showed no significant difference between the groups (P > 0.05).</p><p><b>CONCLUSION</b>The traditional Chinese drugs can significantly decrease blood pressure and LVI in hypertensive rats, and induce cell cycle arrest in G0/G1 phase to reverse left ventricular hypertrophy by regulating the cell cycle and inhibiting the division and proliferation of the cardiac myocytes.</p>