Mockel J, Laurent E, Lejeune C, Dumont J E
Department of Endocrinology, Hôpital Erasme, Brussels, Belgium.
Mol Cell Endocrinol. 1991 Dec;82(2-3):221-7. doi: 10.1016/0303-7207(91)90035-q.
The effects of thyrotropin (TSH) and carbamylcholine (Cchol) on labeling by [3H]inositol of inositol lipids (i.e. total phosphoinositides (PI)) and inositol phosphates (IP) and on diacylglycerol (DAG) generation was studied in dog thyroid slices. Both agents (TSH 1-250 mU/ml, Cchol 10(-6) to 10(-4) M) increased the incorporation of [3H]inositol into PI and IP during 4 h labeling experiments; but the [3H]IP/[3H]PI ratio as compared to the control one was not modified by TSH (10 mU/ml: 1.03 +/- 0.24) while it was increased by Cchol (10(-5) M: 6.14 +/- 1.81). Slices prelabeled in the absence of agonists were then incubated in the presence or absence of 10 mM LiCl +/- 10(-4) M inositol. With LiCl alone, Cchol increased [3H]IP generation, while no such effect of TSH could be detected. However, in the absence of LiCl or in the presence of both LiCl and 10(-4) M inositol, TSH and Cchol both increased [3H]PI and [3H]IP, but IP and PI labeling remained strictly proportional with TSH (10 mU/ml: [3H]IP/[3H]PI ratio = 1.03 +/- 0.06 vs. control), while Cchol increased this ratio (10(-5) M = 2.44 +/- 0.24) with a preferential accumulation of IP. Both agonists stimulated DAG formation with similar kinetics and maximal effects (400% of control at 60 min).(ABSTRACT TRUNCATED AT 250 WORDS)
在犬甲状腺切片中研究了促甲状腺激素（TSH）和氨甲酰胆碱（Cchol）对[3H]肌醇标记肌醇脂质（即总磷酸肌醇（PI））、肌醇磷酸（IP）以及二酰基甘油（DAG）生成的影响。在4小时标记实验中，两种试剂（TSH 1 - 250 mU/ml，Cchol 10(-6)至10(-4) M）均增加了[3H]肌醇掺入PI和IP的量；但与对照相比，TSH（10 mU/ml：1.03±0.24）未改变[3H]IP/[3H]PI比值，而Cchol（10(-5) M：6.14±1.81）使其增加。然后将在无激动剂情况下预标记的切片在有或无10 mM LiCl±10(-4) M肌醇存在下孵育。单独使用LiCl时，Cchol增加了[3H]IP生成，而未检测到TSH有此作用。然而，在无LiCl或同时存在LiCl和10(-4) M肌醇时，TSH和Cchol均增加了[3H]PI和[3H]IP，但IP和PI标记与TSH仍严格成比例（10 mU/ml：[3H]IP/[3H]PI比值 = 1.03±0.06 vs. 对照），而Cchol增加了该比值（10(-5) M = 2.44±0.24），且IP优先积累。两种激动剂均以相似的动力学和最大效应刺激DAG形成（60分钟时为对照的400%）。（摘要截短于250字）
