LIPOXYGENASE ACTIVITY IN HEART-CELLS

Arachidonic acid (AA) metabolism via the lipoxygenase (LOX) pathway in rat hearts and in cultured rat cardiomyocytes was investigated using 1-[C-14]AA, LOX activity was detected in the microsomal fraction, in t he high speed supernatant prepared from rat hearts and in rat cardiomy ocyte supernatant. LOX products from all fractions comigrated in thin layer chromatography as 12-hydroxyeicosatetraenoic acid (12-HETE) and 15-HETE. Enzyme linked immunosorbent assay for 12-HETE showed its form ation by the microsomal fraction, the ammonium sulfate (AS) pellet, an d by rat cardiomyocyte supernatant, while radioimmunoassay for 15-HETE showed its formation only by the AS pellet, The properties of LOX in each fraction are reported here.