Thyroxine and Propylthiouracil Effects on Alpha- and Beta‐Adrenergic Receptor Number, ATPase Activities, and Sialic Acid Content of Rat Cardiac Membrane Vesicles
Thyroxine and Propylthiouracil Effects on Alpha- and Beta‐Adrenergic Receptor Number, ATPase Activities, and Sialic Acid Content of Rat Cardiac Membrane Vesicles
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甲状腺素和丙基硫氧嘧啶对大鼠心肌膜囊泡的α和β肾上腺素能受体数量、ATP酶活性和唾液酸含量的影响
DOI：
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发表时间：
1979
影响因子：
3
通讯作者：
R. Lefkowitz
中科院分区：
文献类型：
--
作者：
M. McConnaughey;L. Jones;A. M. Watanabe;H. R. Besch;L. Williams;R. Lefkowitz
对甲状腺功能正常、甲状腺功能亢进和甲状腺功能减退大鼠心脏的膜囊泡制剂进行了分析，试图识别可能与这些甲状腺状态下发生的已知功能变化相关的生化变化。在三种甲状腺状态的动物心脏的膜囊泡制剂中测量了几种已被证明影响心肌收缩力的肌膜成分。这些成分包括α-和β-肾上腺素能受体的表观数量（根据放射性标记的肾上腺素能拮抗剂的特异性结合来判断）和Na-、K-ATP酶活性。作为制剂中肌膜恢复的对照，测量所有制剂中的唾液酸含量。还测量了 K-, Ca2--ATP 酶（一种调节细胞内离子化 Ca2- 浓度的肌浆网酶）的活性。与甲状腺功能正常的对照组相比，甲状腺素治疗的甲状腺功能亢进大鼠的膜囊泡中α-肾上腺素能受体的表观总数减少（41%，p < 0.01），而β-肾上腺素能受体的表观总数增加（43%，p < 0.001）。与甲状腺正常对照相比，用丙硫氧嘧啶治疗的甲状腺功能减退大鼠制备的膜囊泡的 α-肾上腺素能受体（29%，p < 0.01）和 β-肾上腺素能受体（23%，p < 0.05）的表观总数有所减少。甲状腺功能亢进动物中β受体与α受体的比例大约翻倍，但与从甲状腺功能减退动物分离的膜中的对照相比保持不变。在相同的膜囊泡制剂中，无论甲状腺状态如何，总唾液酸含量相似。此外。
Membrane vesicle preparations from the hearts of euthyroid, hyperthyroid, and hypothyroid rats were analyzed in an attempt to identify biochemical changes which might correlate with known functional changes occurring in these thyroid states. Several sarcolemmal constituents which have been shown to influence myocardial contractility were measured in membrane vesicle preparations from the hearts of animals in the three thyroid states. These constituents included the apparent number of alpha- and beta-adrenergic receptors (judged from specific binding of radiolabeled adrenergic antagonists) and Na-, K--ATPase activity. As a control for the recovery of sarcolemma in the preparations, the sialic acid content was measured in all preparations. The activity of K-, Ca2--ATPase, a sarcoplasmic reticulum enzyme which regulates intracellular ionized Ca2- concentration, was also measured. Membrane vesicles of the thyroxine-treated hyperthyroid rats showed a decrease (41%, p < 0.01) in the total apparent number of alpha-adrenergic receptors relative to euthyroid controls and an increase in the total apparent number of beta-adrenergic receptors (43%, p < 0.001). Membrane vesicles prepared from propylthiouracil-treated hypothyroid rats showed a decrease relative to euthyroid controls in the total apparent number of both alpha-adrenergic receptors (29%, p < 0.01) and beta-adrenergic receptors (23%, p < 0.05). The ratio of beta- to alpha-receptors approximately doubled in the hyperthyroid animals but remained unchanged compared to controls in the membranes isolated from hypothyroid animals. In the same membrane vesicle preparations, total sialic acid content was similar regardless of thyroid state. In addition.