Altered lipoxygenase metabolism and decreased glutathione peroxidase activity in platelets from selenium-deficient rats

• Published in: Biochemical and biophysical research communications Vol. 92; no. 1; pp. 268 - 276
• Main Authors: Bryant, Robert W., Bailey, J.Martyn
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.1980
• Subjects: Animals; Aspirin - pharmacology; Blood Platelets - drug effects; Blood Platelets - enzymology; Erythrocytes - enzymology; Glutathione Peroxidase - blood; Lipoxygenase - metabolism; Male; Peroxidases - blood; Rats; Selenium - deficiency; GSH-Px; THETE; 12-HPETE; 12-HETE; TXB 2; ME; TMS
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/0006-291X(80)91548-X

Washed platelets from selenium-deficient and control rats were incubated with [1- 14C]-arachidonic acid and the lipoxygenase and cyclooxygenase products were identified by gas chromatography/mass spectrometry. Platelets from selenium-deficient rats showed a three to four-fold increased synthesis of the lipoxygenase-derived isomeric trihydroxy fatty acids, 8,9,12-trihydroxy-5,10,14-eicosatrienoic acid and 8,11,12-trihydroxy-5,9,14-eicosatrienoic acid. A major reduction in glutathione peroxidase activity was also observed in platelets from deficient rats. These results support the interpretation that these trihydroxy fatty acids arise from breakdown of the primary platelet lipoxygenase product L -12-hydroperoxy-5,8,10,14-eicosatetraenoic acid (12-HPETE) under conditions in which its reduction to the L -12-hydroxy product (12-HETE) by a selenium-dependent glutathione peroxidase is limited. Further-more, these results indicate a specific function for selenium in platelet metabolism of essential fatty acids.