Toxic inhibition of some dehydrogenases by methyl sterculate--a natural occurring substance in cotton seeds.
According to the present study, crude preparations of rainbow trout liver and rabbit muscle lactate dehydrogenase (LDH,EC 1.1.1.27) were not inhibited by methyl sterculate and oleate, while trout liver glucose-6-phosphate dehydrogenase (G6PDH,EC 1.1.1.49) was activated by these esters. Methyl sterculate inhibited purified preparations of trout liver, rabbit muscle, and bovine heart LDH in contrast to methyl oleate which inhibited only a portion of the activity of purified rabbit muscle LDH and had no appreciable effect on the activities of the other purified LDH preparations. Trout liver LDH preparations were not inhibited by p-Chloromercuribenzoate (pCMB), while rabbit muscle and bovine heart LDH were sensitive to the presence of this inhibitor. Trout liver G6PDH was activated at the lower concentrations of pCMB. These data suggest that the reduction of the activities of liver dehydrogenases in the rainbow trout fed a diet containing methyl sterculate was not due to inhibition of these dehydrogenases by this cyclic fatty acid.
D000818:Animals; D003369:Cottonseed Oil / Q000494:pharmacology*; D003521:Cyclopropanes / Q000494:pharmacology*; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D008099:Liver / Q000201:enzymology; D009132:Muscles / Q000201:enzymology; D011817:Rabbits; D013053:Spectrophotometry; D014337:Trout
D003369:Cottonseed Oil; D003521:Cyclopropanes; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; C023396:methyl sterculate; D007770:L-Lactate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase