Effect of different antihypertensive drugs on blood pressure variability and atherosclerosis in spontaneously hypertensive rats

Objective To evaluate the effect of amlodipine, benazepril and metoprolol on blood pressure variability and atherosclerosis in high-fat-fed spontaneously hypertensive rats（SHR）. Methods Forty male SHRs were randomly divided into SHR group, SHR+hyperlipid group, amlodipine group, benazepril group and metoprolol group. Atherosclerosis models were established in SHR+hyperlipid group, amlodipine group, benazepril group and metoprolol group by high fat feeding and vitamin D₃ peritoneal injection. Rats in amlodipine group, benazepril group and metoprolol group were given amlodipine benzenesulfonate 10 mg/（kg·d）, benazepril hydrochloride 10 mg/（kg·d） and metoprolol tartrate 150 mg/（kg·d）, respectively. Non-invasive tail blood pressure monitoring was performed before grouping（baseline） and 12 weeks after intervention. After 12 observation periods, serum lipids and high sensitivity C reactive protein（hsCRP）, myeloperoxidase（MPO）, lipoprotein-associated phospholipase 2（Lp-PLA2） were measured and the pathological sections of thoracic aorta were taken to make paraffin sections. HE staining was used to evaluate the degree of atherosclerosis. Results Compared with metoprolol group, the standard deviation（SD） value （8.07±4.23）,（12.20±5.92） vs（19.02±4.97） mm Hg and cofficient of variation（CV） （5.05±2.67）%,（7.50±3.83）% vs（12.00±4.06）%, P＜ 0.01 of systolic blood pressure in amlodipine group and benazepril group were lower, and the serum Lp-PLA2 value （146.4±18.5）,（147.0±24.0） vs（169.2±36.8） ng/mL, P＜0.05 were lower. The degree of aortic atherosclerosis in thoracic aorta was lower in amlodipine and benazepril group. Conclusion Amlodipine and benazepril can reduce blood pressure variability and reduce the severity of atherosclerosis in SHRs more than metoprolol.