Plasma activity of pyruvate kinase and glutamic oxalacetic transaminase as indices of myopathy in the vitamin E deficient rat.
Weanling rats were fed vitamin E deficient diets for 6 to 15 weeks and then given vitamin E orally for 4 days. Plasma obtained 1 day after the last dose was assayed for glutamic oxalacetic transaminase (GOT) and pyruvate kinase activity (PK). Administration of vitamin E resulted in reduction in activity of both  enzymes. Plasma levels of alkaline phosphatase, lactic dehydrogenase, and bilirubin were unaffected by vitamin E and there was no histological evidence of liver degeneration. The number of phagocytized muscle fibers was greatly reduced by vitamin E treatment, but a substantial number of necrotic fibers were still present. With more prolonged (8 days) treatment, plasma PK and GOT levels were reduced to levels found in plasma of vitamin E replete animals and few degenerated muscle fibers could be observed. It was concluded that resolution of the necrotizing myopathy in vitamin E deficient rats is a rapid process and that the decreased activity of PK and GOT in plasma is a sensitive indicator of the resolution process. The decrease in plasma enzyme levels is an easily quantitated and reproducible biological response to vitamin E administration. Thus, this approach provides a basis for a sensitive and accurate bioassay for vitamin E activity.
D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood*; D001681:Biological Assay; D008297:Male; D009135:Muscular Diseases / Q000201:enzymology* / Q000209:etiology; D009336:Necrosis; D010587:Phagocytosis / Q000187:drug effects; D011770:Pyruvate Kinase / Q000097:blood*; D051381:Rats; D014810:Vitamin E / Q000378:metabolism / Q000627:therapeutic use; D014811:Vitamin E Deficiency / Q000150:complications / Q000188:drug therapy / Q000201:enzymology*
D014810:Vitamin E; D001219:Aspartate Aminotransferases; D011770:Pyruvate Kinase