[Activity of different dehydrogenases and alkaline phosphatase in manganese deficiency]

The enzyme activities of the isocitrate, glucose-6-phosphate and malate dehydrogenases and of malic enzyme in liver, of lactate dehydrogenase in serum, and of alkaline phosphatase in bone and serum were determined in early-weaned rats given different Mn supplies. The activities of malate dehydrogenase were reduced by 16 and 18% during suboptimum and deficient Mn supply, respectively, the values of alkaline phosphatase in serum and bone were elevated by 29 and 35%, respectively. The enzyme values of the glucose-6-phosphate and lactate dehydrogenases were elevated only during Mn deficiency (by 40 and 65%, respectively), while a suboptimum Mn supply had no noticeable influence on these enzymes. The activities of isocitrate dehydrogenase and of malic enzyme, which were described to be activated by Mn++ in vitro, did not respond in vivo to Mn deficiency.