β-blocker の脂質代謝に及ぼす影響

Abstract

Effective β-adrenergic blocking agent propranolol was administered for eight weeks (60mg daily for initial seven weeks and 120mg for successive one week) to investigate its action on plasma lipids and lipoprotein metabolism in patients with atherosclerosis. Subjects selected for studies were each five male and female post-apoplectic inpatients with normal plasma lipids.Plasma FFA was gradually but significantly elevated with propranolol following initial slight reduction. Incorporation of U-14C-glucose into plasma total fatty acid and cholesterol fractions were also accelelated significantly. Reduced β-oxidation and reesterification of fatty acid and increased fatty acid synthesis may be responsible for these effects of propranolol. Elevation of triglyceride and total lipids of VLDL and concomitant reduction of LDL and HDL were observed. Apolipoprotein VLDL, however, remained stable and apolipoprotein LDL and HDL decreased. FFA release with heparin and postheparin lipolytic activity were apparently suppressed with propranolol.These results suggest that propranolol inhibits the conversion of VLDL to LDL and probably to HDL through inhibition of lipoprotein lipase activity. Examination about the effect of propranolol on the synthesis of lipoprotein lipase, its release into blood stream and on its enzymatic activity is in progress.