Effects and potential mechanism of atorvastatin treatment on Lp-PLA2 in rats with dyslipidemia.

Introduction: The effects of statins on lipoprotein-associated phospholipase A2 (Lp-PLA2) are controversial, and the present study aimed to investigate whether atorvastatin could reduce Lp-PLA2 in rats with dyslipidemia.

Material and methods: A high-fat and high-cholesterol diet was prescribed to produce a dyslipidemia model. Thereafter, low-dose atorvastatin (5 mg/kg/day), high-dose atorvastatin (20 mg/kg/day) or saline (without-treatment group) was prescribed for 14 days. At 6 weeks after dyslipidemia model establishment and 14 days of atorvastatin treatment, fasting venous blood was drawn for biochemical analysis. Between-group differences and Pearson correlation analysis were conducted.

Results: Compared to the normal-control group, fasting plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels were significantly increased in dyslipidemia groups, while plasma nitric oxide (NO) levels were significantly decreased with attendant elevation of plasma C-reactive protein (CRP) and rho-associated kinase 1 (ROCK1) levels ( p < 0.05). At 14 days of atorvastatin treatment, compared to the without-treatment group, plasma levels of TC and LDL-C in the high-dose group were significantly reduced ( p < 0.05); and compared to low-dose and without-treatment groups, NO up-regulation (1.8 ±1.1 μmol/l), and CRP (-0.8 ±0.4 ng/ml), ROCK1 (-124 ±65 mmol/l) and Lp-PLA2 (-3.8 ±1.2 ng/ml) reduction were more significant in the high-dose group ( p < 0.05). Pearson correlation analysis showed that TC ( r = 0.365), LDL-C ( r = 0.472), CRP ( r = 0.501) and ROCK1 ( r = 0.675) were positively correlated with Lp-PLA2, while NO ( r = -0.378) and atorvastatin ( r = -0.511) were negatively correlated with Lp-PLA2.

Conclusions: Atorvastatin treatment is beneficial for reducing the Lp-PLA2 level in rats with dyslipidemia, which may be related to reduced ROCK1 expression in a dose-dependent manner.