Molecular species of phosphoglycerides in liver microsomes of rats fed a fat-free diet.
The influence of a fat-free diet on the molecular species composition of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylinositol (PI) of rat liver microsomes was studied by using reversed-phase high-pressure liquid chromatography. In the three phosphoglyceride classes analyzed, the fat-free diet produced a large decrease in the 18:0/20:4n-6 species but less important changes were found in the 16:0/20:4n-6 species. In PC, the most abundant phosphoglyceride class of rat liver microsomes, the fall in the 18:0/20:4n-6 species was counterbalanced mainly by an enhancement in the 16:0/18:1n-9 species although it was not evident in PE. In PI, the decrease in the 18:0/20:4n-6 species was counterbalanced by an increase in the 18:0/20:3n-9 species. Fluorescence polarization measurements of 1,7-diphenyl-1,3,5-hexatriene in liposomes of 16:0/18:1n-9, 18:0/18:1n-9-, 16:0/20:4n-6-, and 18:0/20:4n-6-PC indicated that the change in the saturated fatty acid in the sn-1 position accompanying the replacement of 20:4n-6 by 18:1n-9 could be very important for a homeoviscous compensation, maintaining the membrane physical properties without large alterations in spite of the essential fatty acid deficiency due to the fat-free diet.
Garda
H A
HA
Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CONICET-UNLP, Facultad de Ciencias Médicas, Argentina.
Bernasconi
A M
AM
Tricerri
M A
MA
Brenner
R R
RR
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D018752:Diet, Fat-Restricted; D005227:Fatty Acids / Q000032:analysis*; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D005454:Fluorescence Polarization; D008081:Liposomes; D008297:Male; D008862:Microsomes, Liver / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000032:analysis / Q000737:chemistry*; D010714:Phosphatidylethanolamines / Q000032:analysis / Q000737:chemistry*; D010716:Phosphatidylinositols / Q000032:analysis / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar
D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008081:Liposomes; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010716:Phosphatidylinositols