Folate and folate-dependent enzymes associated with rat CNS development

Folic acid and its derivatives are important mediators in growth-related ce llular processes. The concentration of folate and two folate-dependent enzy mes, 10-formylte-trahydrofolate synthetase (10-FTHFS) and 10-formylte-trahy drofolate dehydrogenase (10-FTHFDH), was determined in brain regions over t he early period of rat development. Folate concentrations determined at bir th were high in all brain regions studied. During the first 2 weeks, folate concentrations declined steadily, followed by a period of significant incr ease. High and invariant activity of 10-FTHFS was found throughout the peri od of study. Low amounts of 10-FTHFDH were seen for the first 2 weeks, but increased significantly from postnatal days 14 to 28. These changes correla ted with changes determined in the concentration of folate, supporting the idea that this protein is involved with folate uptake and/or storage. Furth ermore, immunohistochemical expression of 10-FTHFDH in different rat brain regions revealed glial cells as a preferential cellular location for this f olate-binding protein.