Modified gravitational field and lactate dehydrogenase activity.

The paper deals with the effects of the gravitational field investigated either by hypokinesia with corresponding diminution of muscle solicitation, or by centrifugation, that is by rise of gravitational solicitation, on lactate dehydrogenase activity of rats. After 7 days of hypokinesia the activity of lactate dehydrogenase is significantly changed by the elevation of LDH5 isoenzyme, both in serum and in myocardium. The enhancement is by 40% in serum and by 30% in myocardium against the control group. In centrifuged rats the enhancement of LDH5 isozyme is much lesser than in hypokinetic rats, that is by 18% in myocardium and by 20% in serum against the control group. The total of all LDH1-5 isozymes was found in cardiac muscle of both hypokinetic, centrifuged and control group. In serum only two fractions LDH2 and LDH5 isozymes appear both in hypokinetic, centrifuged and control group.