Effect of thyroid status on the development of the different molecular forms of Na+,K+-ATPase in rat brain.
The effect of thyroid status on the postnatal development of the two molecular forms of Na+,K+-ATPase, distinguished kinetically on the basis of their ouabain sensitivity, was examined in rat brain. Hypothyroidism induced by PTU from day 1 postnatally significantly reduced the Na+,K+-ATPase activity in cerebellum (22-30 days) but not forebrain, whereas hyperthyroidism (T4 treatment from day 1) had no effect. The hypothyroidism-induced reduction in cerebellum was reflected by a 20-45% reduction in the activity of the alpha(+) form of Na+,K+-ATPase (high ouabain affinity) against control brains compared to a 60-70% reduction in the activity of the alpha form (low ouabain affinity). These results show that neonatally induced hypothyroidism leads to a selectively greater impairment of the ontogenesis of the activity of cerebellar alpha form of Na+,K+-ATPase. This may possibly reflect a retarded development of a selective cerebellar cell population containing predominantly the alpha form of the enzyme.
Atterwill
C K
CK
Reid
J
J
Athayde
C M
CM
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000201:enzymology / Q000254:growth & development*; D017301:Ca(2+) Mg(2+)-ATPase; D002531:Cerebellum / Q000201:enzymology; D055598:Chemical Phenomena; D002621:Chemistry; D004027:Diencephalon / Q000201:enzymology; D006980:Hyperthyroidism / Q000139:chemically induced / Q000201:enzymology*; D007037:Hypothyroidism / Q000139:chemically induced / Q000201:enzymology*; D008297:Male; D011441:Propylthiouracil; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013687:Telencephalon / Q000201:enzymology; D013974:Thyroxine
D011441:Propylthiouracil; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase; D013974:Thyroxine