Activities of NAD-and NADP-specific isocitrate dehydrogenases in kidney mitochondria of rachitic rat.

In the previous research we have demonstrated that rats fed on a rickets-inducing diet show increasing citrate levels in kidney and intestinal mucosa. The study of the enzymes related to citrate metabolism has shown that both NAD+-and NADP+-dependent isocitrate dehydrogenases decrease in kidney mitochondria of rachitic rat. The inhibitory effect of Ca2+ and citrate on the activity of the two dehydrogenases has been also investigated; these metabolites behave as competitive inhibitors against Mg2+ both in normal and in rachitic rats.