Isolated brain capillary endothelia: influence of various levels of essential fatty acids on the acyl group composition of glycerophospholipids.

On day seven of gestation. Wistar rats were assigned to a high essential fatty acid (EFA), low EFA, or a fat free diet. The same diets were continued during lactation. On weaning, the offspring were fed the same diets as their mother. Rats were killed at 222 days, brain capillary endothelia isolated, and total lipids extracted from the purified capillaries. The composition of the constituent fatty acids of ethanolamine glycerophospholipid (EGP), choline glycerophospholipid (CGP), and the alk-1-enyl EGP composition from each diet is reported. A decrease in dietary EFA led to reduced proportions of total saturated acyl groups in EGP with no change observed in the total saturated acyl groups from CGP, and an increase in monoenoic fatty acids, particularly 18:1n-9 for each phospholipid class. The proportions of 20:4n-6 in alk-1-enyl EGP were reduced in fat-free fed animals. In addition, the relationship between 20:3n-9 and 20:4n-6 fatty acids in brain capillary endothelia were markedly increased with a reduction in dietary fat. Low EFA and fat deficient animals showed a tendency to sequester 22:6n-3.