VITAMIN-D-RELATED MODIFICATION OF ENZYME-ACTIVITIES IN SYNAPTOSOMES AND MITOCHONDRIA ISOLATED FROM RAT CEREBRAL-CORTEX

We previously demonstrated that feeding rats the Steenbock and Black r ickets-inducing diet produces remarkable changes in the metabolic patt ern of intestinal mucosa, kidney, liver, cerebral cortex and heart. We have now determined the levels of calcium, phosphorus and citrate in cerebral cortex and the activity of some enzymes in synaptosomes and c erebral cortex mitochondria of three rat groups: control (Group A), fe d a vitamin D-deficient diet (Group B), fed a vitamin D-deficient diet and treated with 1,25-dihydroxyvitamin D-3 (Group C). While calcium c ontent increased in Groups B and C, phosphorus concentration increased only in Group C and citrate in Group B in comparison with control. Th e increase in acetylcholinesterase and citrate synthase registered in Group B was restored to control values by 1,25-dihydroxyvitamin D-3 tr eatment, while, neither the decrease in cytochrome c oxidase, nor the increase in glucose-6-phosphate dehydrogenase, acid phosphatase and NA DP(+)-isocitrate dehydrogenase observed in Group B were corrected by 1 ,25-dihydroxyvitamin D-3 supply. Acyl phosphatase showed a remarkable increase in consequence of 1,25-dihydroxyvitamin D-3 administration.