Accession Number : ADA140386

Title :   Arachidonic Acid Metabolism by Platelets of Differing Size.

Descriptive Note : Technical rept.,


Personal Author(s) : Jakubowski,J A ; Thompson,C B ; Vaillancourt,R ; Valeri,C R ; Deykin,D

PDF Url : ADA140386

Report Date : 10 Mar 1983

Pagination or Media Count : 21

Abstract : The relationship between mean platelet volume (MPV) and platelet arachidonic acid metabolism was examined by studying the ability of human platelets of different size to incorporate and metabolize tritiated arachidonic acid ((3H)AA). Platelet phospholipids were labelled with (3H)AA and the platelets were then fractionated into size-dependent subpopulations by counterflow centrifugation. The incorporation of (3H)AA increased through the fractions proportional to the MPV. After thrombin stimulation the percent of total 3H-radioactivity released from the platelets decreased as the MPV increased. However, fractionation of the released 3H-radioactivity by HPLC (high performance liquid chromatography) demonstrated that MPV had no significant influence on the percent of total platelet 3H-radioactivity released as cyclooxygenase products or as HETE (12-hydroxyeicosatetraenoic acid) but that the release of unmetabolized (3H)AA decreased as MPV increased. Results demonstrated that the release of arachidonic acid metabolites is qualitatively similar in platelets of different size. However, the absolute ability of platelets to incorporate arachidonic acid, convert it to active metabolites and release them is proportional to their volume. The ability of platelets to release unmetabolized arachidonic acid varies inversely with their MPV.

Descriptors :   *Fatty acids, Metabolism, Blood platelets, Phospholipids, Tritiated compounds, Blood, Collection, Isolation, Labeled substances

Subject Categories : Biochemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE