[Furosemide-induced changes in the inhibiting action of urea and lactate dehydrogenase isoenzyme]

Experiments on rat tissues in vitro showed that the effect of furosemide on the activity of lactate dehydrogenase significantly changes against the background of the action of 2M urea. Furosemide decreases the activity of urea-stable fractions of lactate dehydrogenase in the kidney tissues at concentrations of 10(-6) and 10(-7) M, whereas in the liver and heart tissues this effect occurs at the concentration of 10(-3) M. However the introduction of furosemide in the incubation mixture before the addition of urea eliminates its inhibitory effect on lactate dehydrogenase activity in the kidney and its cortical layer at the concentration of 10(-6) M, in the medulla at 10(-5) M and in the liver and heart tissues only at 10(-3) M.