title: Membrane polyunsaturated fatty acids and lithium-sodium countertransport in human erythrocytes.
abstract: Two groups of individuals, 26 normotensive normolipemic and 37 normotensive hyperlipemic, all without family history of hypertension have been selected in attempt to demonstrate whether Li-Na countertransport of erythrocytes is influenced by plasma and membrane lipid composition. The maximal rate of Li-Na countertransport was elevated in hyperlipemics (0.344 +/- 0.168 vs 0.220 +/- 0.074 mmol/l erythrocytes/h). This difference is highly significant. Hyperlipemics had different composition of membrane lipids than normals. The most important variations were: increase of palmitic, palmitoleic and total saturated fatty acids (SFA) as well as increase of cholesterol/phospholipids ratio (C/PL); in contrast, hyperlipemics had a reduced amount of linoleic acid and total unsaturated fatty acids (UFA) as well as total polyunsaturated fatty acids (PUFA). Consequently, UFA/SFA and PUFA/SFA ratios were lower than in normals. Li-Na countertransport was negatively correlated with the amount of PUFA (P less than 0.02), whereas it was positively correlated with the following parameters: oleic/linoleic ratio (p less than 0.02), monounsaturated fatty acids/polyunsaturated fatty acids ratio (p less than 0.03) as well as with the SFA + monounsaturated fatty acid/PUFA ratio (p less than 0.03). These findings suggest that the V max of Li-Na countertransport in erythrocytes is influenced by the lipid composition of the membrane.
mesh_terms: D000328:Adult; D001692:Biological Transport; D001794:Blood Pressure; D004910:Erythrocyte Membrane / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D006801:Humans; D008055:Lipids / Q000097:blood; D008094:Lithium / Q000097:blood*; D008297:Male; D008563:Membrane Lipids / Q000097:blood; D008875:Middle Aged; D012964:Sodium / Q000097:blood*
chemical_list: D005231:Fatty Acids, Unsaturated; D008055:Lipids; D008563:Membrane Lipids; D008094:Lithium; D012964:Sodium