Effects of oxprenolol treatment on pseudocholinesterase and lipids in rats

The effect of chronic treatment with the non-selective beta-blocker oxprenolol (CAS 6452-71-7) administered orally in two different doses (15 or 30 mg/kg/day for 6, 10 and 12 weeks) on plasma cholinesterase (PChE) activity and on the plasma level of triglyceride and total cholesterol were studied in normal rats. In all treated groups a significant increase (approximately 27-51%) of PChE activity was obtained (p < 0.05 vs. control group). The plasma concentration of total cholesterol was significantly increased as well (21-48%, p < 0.05 vs. control) but oxprenolol exerted no significant effect on plasma triglyceride levels. The increase of enzyme activity and total cholesterol were not time- or dose-dependent. According to these results which showed a direct relationship between PChE activity and total cholesterol it is supposed that the increase of enzyme activity is initially due to the action of oxprenolol on total cholesterol metabolism but that it does not have a direct effect on the enzyme. The results contribute to the hypothesis that PChE plays a role in lipoprotein metabolism although this has not yet been proven.