Effect of hydrocortisone and thyroxine on ATPase activities of neuronal and glial cell lines in culture.

The effect of hydrocortisone and thyroxine, on the activities of Ca2+- and Mg2+- ATPase was studied in cultured neuronal (clone M1) and glial (clones NN and C6) cell lines. For M1 and NN cells an increase in Ca2+- and Mg2+-ecto-ATPase activity was found when the cells were cultured during 4-6 days in presence of hydrocortisone or together with thyroxine. In the same conditions, a decrease in Ca2+- and Mg2+-ecto-ATPase activity was found for the C6 cells. In C6 cells the effect of hormones was more pronounced for the Mg2+- than for the Ca2+-ecto-ATPase activity. The observed decrease may be related to the tumoral origin of the C6 cells. The activity of (Na+, K+)-ATPase in all three cell lines increased in presence of hydrocortisone or together with thyroxine when the cells were cultured during 4-6 days, in presence of the hormones, whereas the total Mg2+- ATPase activity increased only after 6 days of treatment. Thyroxine alone has very few effect either on Ca2+- and Mg2+-ecto-ATPase, or on (Na+, K+)- and total Mg2+-ATPase activity. These observations are interpreted to indicate that hormones may modulate or induce enzymatic activities involved in active transport phenomena in nervous tissue.