POSTNATAL-DEVELOPMENT OF PLASMA-LIPID-CLEARING ENZYMES (LIPOPROTEIN-LIPASE, HEPATIC LIPASE AND LECITHIN - CHOLESTEROL ACYL TRANSFERASE) AND LIPID PROFILES IN SUCKLING RATS

We examined the activity of plasma circulating lipoprotein lipase and hepatic lipase, lecithin:cholesterol acyl transferase (LCAT), as well as lipid profiles in Sprague-Dawley rats from 1 day until 29 days of age. Plasma lipoprotein lipase activity peaked between ages 5 and 15 days and decreased after weaning, while plasma hepatic lipase activity remained constantly low during the suckling period and increased after weaning. No statistically significant difference in LCAT activity was seen from birth until weaning. Plasma triglycerides, as well as free fatty acids, decreased significantly after birth. Total plasma cholesterol increased during the suckling period and decreased after weaning. HDL cholesterol increased after the first 10 days of life, and free cholesterol remained constant after an initial decrease from birth to the 5th day of life. In conclusion, the enzymes asociated with the metabolism of triglycerides, cholesterols and phospholipids are well developed in the rat shortly after birth.