[Effects of qishenyiqi gutta pills on calcium/calmodulin dependent protein kinase II in rats with renal hypertension].

Objective: To explore the effects of qishenyiqi gutta pills on myocardial hypertrophy of left ventricle and calcium/calmodulin dependent protein kinase II (CAMK II) in rats with renal hypertension and elucidate its intervention mechanism for myocardial hypertrophy.

Methods: A total of 50 Wistar rats were randomly divided into 5 groups of sham-operation, control, high-dose qishenyiqi gutta pills, low-dose qishenyiqi gutta pills and valsartan (n = 10 each). The rat model of myocardial hypertrophy with renal hypertension was established by the 2-kidney 1-clip (2K1C) method. The experimental animals were divided into control, high-dose, low-dose and valsartan groups. At Week 5 postoperation, valsartan group received an oral dose of valsartan (30 mg×kg(-1)×d(-1)), high-dose and low-dose groups took qishenyiqi gutta pills (250 and 125 mg×kg(-1)×d(-1)) while sham-operation and control groups had the same dose of normal saline solution. Tail arterial pressure was detected weekly and continued for 8 weeks. At the end of Week 12, the animals were sacrificed to harvest myocardial tissue of left ventricle for detecting left ventricular mass index (LVMI). The collagen volume fraction (CVF) of myocardium was examined by Van Gieson staining, the activities of superoxide dismutase (SOD) and reactive oxygen species (ROS) were detected by enzyme-linked immunosorbent assay (ELISA) and the expression of CAMK II was detected by immunohistochemistry and Western blot.

Results: (1) Blood pressures were significantly higher in high-dose, low-dose and control groups than those in sham-operation and valsartan groups ((167.66 ± 11.48), (166.72 ± 13.51), (174.34 ± 14.52) vs (119.57 ± 6.30), (131.80 ± 12.49) mm Hg, P < 0.01). The changes of blood pressure had no significant difference between high-dose and low-dose groups. (2) LVMI and CVF increased significantly in high-dose, low-dose and valsartan groups versus sham-operation group (LVMI: (1.98 ± 0.16), (2.09 ± 0.14), (1.97 ± 0.17) vs (1.74 ± 0.17) g/kg; CVF: 0.94% ± 0.22%, 2.53% ± 0.61%, 0.81% ± 0.20% vs 0.45% ± 0.13%) (P < 0.01, P < 0.05), but decreased significantly versus control group (LVMI: (1.98 ± 0.16), (2.09 ± 0.14), (1.97 ± 0.17) vs (2.28 ± 0.28) g/kg; CVF: 0.94% ± 0.22%, 2.53% ± 0.61%, 0.81% ± 0.20% vs 4.73% ± 1.04%) (P < 0.01, P < 0.05). (3) The expression of CAMK II was significantly higher in high-dose, low-dose, valsartan and control groups than that in sham-operation group (65.9%, 95.3%, 84.8%, 160.1% vs 67.7%). And it was significantly lower in high-dose, low-dose and valsartan groups than that in control group (65.9%, 95.3%, 84.8% vs 160.1%). There was no statistical difference among high-dose, low-dose and valsartan groups.

Conclusions: Qishenyiqi gutta pills may retard myocardial hypertrophy of left ventricle in rats with renal hypertension. And the mechanism is probably be correlated with its antioxidant activity and inhibited expression of myocardial CAMK II.