The incorporation of acetate and palmitate into lipids by human platelets

Daniel Deykin; Richard K. Desser

doi:10.1172/JCI105851

The incorporation of acetate and palmitate into lipids by human platelets

Daniel Deykin and Richard K. Desser

Published July 1, 1968 - More info

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Abstract

The optimal conditions for the incorporation of acetate-1-¹⁴C and palmitic acid-1-¹⁴C into platelet lipids have been described. In buffer incubations with acetate there was a sharp pH optimum at 6.8; in plasma incubations, there was a broad pH optimum between 6.8-7.4. Maximal incorporation of acetate occurred at a final concentration of 1.5 mmoles/liter. In buffer, no labeled lipids were released from platelets into the medium. In plasma, 40% of newly formed lipids was recovered in the plasma. 75% of the incorporated acetate could be recovered in ceramide, lecithin, and free fatty acids. Platelet fatty acids were formed both by de novo synthesis and chain elongation. The fatty acids formed by de novo synthesis exchanged with plasma free fatty acids. In buffer incubations no turnover of newly labeled lipids occurred, but in the plasma incubations exchange of newly labeled lecithin with plasma lipids was demonstrable. Palmitic acid-1-¹⁴C added to plasma was incorporated into platelet lipids. The distribution among the lipid classes of palmitate taken up from plasma was the same as that of palmitate formed intracellularly by de novo synthesis.