Tornhamre S, Gigou A, Edenius C, Lellouche JP, Lindgren JA. Conversion of 5,6-dihydroxyeicosatetraenoic acids. A novel pathway for lipoxin formation by human platelets.
FEBS Lett 1992;
304:78-82. [PMID:
1618303 DOI:
10.1016/0014-5793(92)80593-6]
[Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Leukotriene A4 may be metabolized to 5(S),6(R)- and 5(S),6(S)-dihydroxy-7,9-trans-11,14-cis-eicosatetraenoic acids by enzymatic or non-enzymatic hydrolysis. Incubation of human platelet suspensions with these dihydroxy acids led to the formation of lipoxin A4 and 6(S)-lipoxin A4 via lipoxygenation at C-15. Furthermore, human platelets converted the two 5(R),6(S)- and 5(R),6(R)-dihydroxy-7,9-trans-11,14-cis-eicosatetraenoic acids to tetraene-containing trihydroxyeicosatetraenoic acids. In contrast, leukotrienes C4, D4 and E4 were not transformed to cysteinyl-lipoxins. Time-course studies of leukotriene A4 metabolism in human platelet suspensions indicated lipoxin formation via two pathways: (i) direct conversion of leukotriene A4, leading to formation of the lipoxin intermediate 15-hydroxy-leukotriene A4; and (ii) 15-lipoxygenation of the 5(S),6(R)- and 5(S),6(S)-dihydroxyeicosatetraenoic acids. The results demonstrate that lipoxygenation at C-15 of 5,6-dihydroxy-7,9,11,14-eicosatetraenoic acids may be an alternative novel pathway for platelet-dependent lipoxin formation.
Collapse