Haye B, Marcy G, Jacquemin C
Biochimie. 1979;61(8):905-12. doi: 10.1016/s0300-9084(79)80240-0.
The "phospholipid effect" which is the enhanced turnover of the phosphorylinositol group of phosphatidylinositol (PI) occurs in the thyroid of response to thyreostimulin (TSH). The possibility that Ca2+ ions are involved in this stimulation has been investigated with pig thyroid slices. Experiments performed in media without Ca2+ or containing E.G.T.A. (2 mM), indicate that it is not the extracellular Ca2+ which is implied, but rather the intracellular Ca2+. The ionophore A23187 (6.10(-6) M) increases the specific radioactivity of the acid soluble precursors, but has also a specific effect on the PI turnover, which is additive with the effect of a high concentration of TSH (50 mU/ml). Washing and loading of slices with various Ca2+ concentrations show that 0.9 mM restores the TSH phospholipid effect. Verapamil (10(-3) M) and Chlorpromazine (10(-3) M) redirect glycerolipid metabolism by increasing PI and phosphatidic acid (PA) synthesis at the expense of other glycerolipids, as phosphatidylcholine (PC) and phosphatidylethanolamine (PE). These results suggest that the "phospholipid effect" is not a result of Ca2+ entry into the thyroid cells. On the contrary, it seems that this increased turnover of PI in "long term" incubations (3 hr). An additive and acute effect of TSH effect is more pronounced when Ca2+ movements
“磷脂效应”是指磷脂酰肌醇（PI）的磷酸肌醇基团周转增强，它发生在甲状腺对促甲状腺素（TSH）的反应中。已用猪甲状腺切片研究了Ca2+离子参与这种刺激的可能性。在无Ca2+或含有乙二醇双（2-氨基乙基醚）四乙酸（EGTA，2 mM）的培养基中进行的实验表明，涉及的不是细胞外Ca2+，而是细胞内Ca2+。离子载体A23187（6×10⁻⁶ M）增加了酸溶性前体的比放射性，但对PI周转也有特定作用，这与高浓度TSH（50 mU/ml）的作用是相加的。用不同Ca2+浓度对切片进行洗涤和加载表明，0.9 mM可恢复TSH的磷脂效应。维拉帕米（10⁻³ M）和氯丙嗪（10⁻³ M）通过增加PI和磷脂酸（PA）的合成而以其他甘油脂质如磷脂酰胆碱（PC）和磷脂酰乙醇胺（PE）为代价来改变甘油脂质代谢。这些结果表明，“磷脂效应”不是Ca2+进入甲状腺细胞的结果。相反，在“长期”孵育（3小时）中PI周转的增加似乎是这样。当Ca2+移动时，TSH效应的相加和急性效应更为明显
