DIFFERENCE OF THE INVIVO RESPONSIVENESS TO THYROTROPIN STIMULATION BETWEEN THE NEOTENIC AND METAMORPHOSED AXOLOTL, AMBYSTOMA-MEXICANUM - FAILURE OF PROLACTIN TO BLOCK THE THYROTROPIN-INDUCED THYROXINE RELEASE
DIFFERENCE OF THE INVIVO RESPONSIVENESS TO THYROTROPIN STIMULATION BETWEEN THE NEOTENIC AND METAMORPHOSED AXOLOTL, AMBYSTOMA-MEXICANUM - FAILURE OF PROLACTIN TO BLOCK THE THYROTROPIN-INDUCED THYROXINE RELEASE
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DOI：
10.1016/0016-6480(84)90047-9
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发表时间：
1984-01-01
影响因子：
2.7
通讯作者：
KUHN, ER
中科院分区：
文献类型：
--
作者：
DARRAS, VM;KUHN, ER
通过放射免疫测定法，测定了新生期和变态期雄性axololt A的基础和TSH诱导的血浆T4 [甲状腺素]浓度。在绵羊催乳素预处理之前和之后，所有的注射都是在腹静脉进行的。基础水平的T4是低的，在neotenes（85 ±。19 pg/ml），变态钝口线虫略高（171 . ±. 39 pg/ml），但在变态过程中增加（1094 . ±. 138 pg/ml）。注射5 mU牛促甲状腺激素后，幼仔的T4循环水平升高约4倍，但在变态动物中超过50倍。在两个实验组中，分别在注射前24小时和13小时与5 mU TSH同时静脉注射三次，每次注射640 mU催乳素，均不会抑制TSH诱导的释放。在变态的Ambystoma中再次出现> 50倍的T4增加，而在新生期中观察到10倍的TSH诱导的T4释放，这比催乳素处理前更明显。以. mexicanum绵羊催乳素不阻断TSH诱导的T4释放。与甲状腺激素的任何拮抗作用都不是通过甲状腺介导的。
Basal and TSH-induced plasma concentrations of T4 [thyroxine] have been measured by radioimmunoassay in the neotenic and metamorphosed male axololt A. mexicanum both before and after an ovine prolactin pretreatment. All injections are made into the vena abdominalis. Basal levels of T4 are low in neotenes (85 .+-. 19 pg/ml) and somewhat higher in metamorphosed Ambystoma (171 .+-. 39 pg/ml), but are increased during metamorphosis (1094 .+-. 138 pg/ml). Following injection of 5 mU bovine TSH circulating levels of T4 are raised about 4 times in neotenes, but more than 50 times in metamorphosed animals. Three i.v. injections, each of 640 mU prolactin and given, respectively, 24 and 13 h before and simultaneously with 5 mU TSH, do not inhibit the TSH-induced release in both experimental groups. In the metamorphosed Ambystoma again a > 50-fold T4 increase is present, whereas in neotenes a 10-fold TSH-induced T4 release is seen, which is more pronounced than before the prolactin treatment. In A. mexicanum ovine prolactin does not block a TSH-induced T4 release. Any antagonistic action with thyroid hormones is not mediated through the thyroid gland.