EFFECT OF HYPOTHYROIDISM ON IONIC METABOLISM AND Na-K ACTIVATED ATP PHOSPHOHYDROLASE ACTIVITY IN THE DEVELOPING RAT BRAIN1 |
| |
Authors: | Theony Valcana Paola S. Timiras |
| |
Abstract: | The effects of neonatal hypothyroidism on electrolyte contents and the Na+ and K+ activated ATPase system was studied in the cerebral cortex and cerebellum of the developing rat. Neonatal hypothyroidism increased Na+ and CI? contents and decreased K+ and Mg2+ contents in both brain areas. Hypothyroidism also resulted in a decrease in the specific activity of the Na-K ATPase extracted by deoxycholate treatment from brain homogenate as well as in the specific activity of this enzyme in the heavy microsomal fraction. The decrease in Mg2+ content and ATPase activity is discussed in relation to the changes occurring in Na+ and K+. Both enzymic and ionic changes may underlie the biochemical and physiological abnormalities observed when the brain is deprived of thyroxine at critical stages of its development. |
| |
Keywords: | |
|