Effect of free fatty acid mobilization on the electrophoretic mobility of α-lipoproteins in the dog

• Main Authors: MANUEL J. LIPSON, SHAPUR NAIMI
• Format: Article
• Language: English
• Published: Elsevier 1971-05-01
• Series: Journal of Lipid Research
• Subjects: propranolol; nicotinic acid; norepinephrine; catecholamines; β-lipoproteins; atherosclerosis
• Online Access: http://www.sciencedirect.com/science/article/pii/S0022227520395092

Dogs were given infusions of norepinephrine and subsequent additional infusions of propranolol and nicotinic acid over a 4-hr period. Under different physiological conditions, α-lipoproteins of three different electrophoretic mobilities were identified by means of paper electrophoresis; they were designated α-lipoproteins X, Y, and Z. During norepinephrine infusion, α-lipoprotein Y fell from 45% (of all lipoproteins) to 14%. There was a reciprocal rise in α-lipoprotein Z. On the other hand, α-lipoprotein X was not significantly changed. There was evidence that α-lipoprotein Y was progressively transformed into α-lipoprotein Z by increasing plasma FFA concentrations. The percentages of both α-lipoproteins Y and Z returned to original values after the dogs were given either nicotinic acid or propranolol. The alterations in the α-lipoprotein peaks Y and Z were rapid, being noted within 5 min of change in plasma FFA concentration. However, there appeared to be a threshold of plasma FFA concentration of 1200 μEq/liter, below which no changes in α-lipoproteins were noted. It was concluded that α-lipoprotein Y is rapidly, progressively, but reversibly transformed into α-lipoprotein Z by binding to plasma FFA above a threshold level of 1200 μEq/liter. However, α-lipoprotein X does not appear to be involved in the binding of plasma FFA.