Folate metabolism in the superior cervical ganglion histochemical study.

By means of histochemical methods, folic acid, dihydrofolate reductase and NADH2-cytochrome-C-reductase were studied in the bovine superior cervical ganglion, in parallel with quantitative estimations of dihydrofolate reductase activity and in connection with the process of ageing. Various levels of folate metabolism were present in nerve cells and glial cells, as well as in pre or postganglionic nerves. In the process of ageing the activity of dihydrofolate reductase gradually decreased and the folic acid concentration in the nerve cells increased. Thus the enzyme --- substrate ratio appeared to favour the enzyme in young animals but the substrate in old animals.