[The effect of urea on the activity of lactate dehydrogenase from the muscles of swine and skates].
Urea competitively inhibits the reduction of pyruvate by LDH from pig and skate muscles at pyruvate concentrations up to 1 mM, inhibition constant being equal to 400-500 mM. It increased the value of Michaelis constant for pyruvate, activated both dehydrogenases with a maximum effect near 0.5-0.6 M. The level of activation of LDH from pig muscles was rather stable amounting to 10-20%, whereas it increased for the enzyme of the skate with the increase of pyruvate concentration up to 30 mM. Similarly, although less effectively, both dehydrogenases were activated by KCl solutions.
Lushchak
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D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D066298:In Vitro Techniques; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors / Q000187:drug effects* / Q000302:isolation & purification / Q000378:metabolism; D009132:Muscles / Q000201:enzymology*; D011773:Pyruvates / Q000494:pharmacology; D019289:Pyruvic Acid; D012860:Skates, Fish; D013552:Swine; D014508:Urea / Q000494:pharmacology*
D011773:Pyruvates; D019289:Pyruvic Acid; D014508:Urea; D007770:L-Lactate Dehydrogenase
Vliianie mocheviny na aktivnost' laktatdegidrogenazy iz myshts svin'i i skata.