Tobin R B, Berdanier C D, Ecklund R E
J Environ Pathol Toxicol. 1979 Jul-Aug;2(6):1235-45.
The effects of T4 and T3 upon ATPase activity of plasma membrane preparations produced by different methods has been studied. Media without Na+ or K+ was used to identify Mg++ activated ATPase, and media containing 100-120 mM Na+ and 20-30 mM K+ in addition to Mg++ was used to identify the augmented activity of Na-K ATPase. We also utilized media containing Na+, K+, and Mg++ in the presence and absence of ouabain to identify the Na+-K+ activation. We found no effect of doses of thyroxine in the physiologic range upon the Na+-K+ ATPase activity. A dose-response study indicated that high doses of T4 may stimulate Mg++ activated ATPase. In the P2 preparation of the Touster method we found minimally enhanced Na+-K+ ATPase activity. The quantity of T4 needed to cause such enhancement is approximately 50 times the physiologic replacement dose needed to restore thyroidectomized animals to a euthyroid state. We conclude that thyroid hormones do not stimulate Na+-K+ ATPase of plasma membranes when administered in a physiologic quantity, but may enhance Mg++ atpase activity when administered in a pharmacologic or toxic quantity.
研究了 T4 和 T3 对不同方法制备的质膜制剂 ATP 酶活性的影响。不含 Na+ 或 K+ 的培养基用于鉴定 Mg++ 激活的 ATP 酶，除 Mg++ 外还含有 100 - 120 mM Na+ 和 20 - 30 mM K+ 的培养基用于鉴定 Na - K ATP 酶的增强活性。我们还利用含有 Na+、K+ 和 Mg++ 且存在或不存在哇巴因的培养基来鉴定 Na+-K+ 激活。我们发现生理范围内的甲状腺素剂量对 Na+-K+ ATP 酶活性没有影响。剂量反应研究表明，高剂量的 T4 可能刺激 Mg++ 激活的 ATP 酶。在 Touster 方法的 P2 制剂中，我们发现 Na+-K+ ATP 酶活性略有增强。引起这种增强所需的 T4 量约为使甲状腺切除动物恢复到甲状腺功能正常状态所需生理替代剂量的 50 倍。我们得出结论，甲状腺激素以生理量给药时不会刺激质膜的 Na+-K+ ATP 酶，但以药理或毒性量给药时可能增强 Mg++ ATP 酶活性。
