Ronning S A, Martin T F
Biochem Biophys Res Commun. 1985 Jul 31;130(2):524-32. doi: 10.1016/0006-291x(85)90448-6.
We have used GH3 cells permeabilized by electric field discharge to examine the effects of Ca2+ and protein kinase C activators (phorbol ester and diacylglycerol) on prolactin (PRL) release. Ca2+ was found to stimulate PRL release approximately 4 fold at 3 microM Ca2+ with a half-maximal response at approximately .5 microM estimated free Ca2+. 12-O-tetradecanoyl phorbol-13-acetate and 1-oleoyl-2-acetyl-sn-glycerol stimulated PRL release throughout a range of Ca2+ concentrations (1 nM -3 microM), but stimulation was greater at higher Ca2+ concentrations (.1 microM to 1 microM). Both agents decreased by 1.8 fold the apparent [Ca2+] at which half-maximal stimulation of secretion occurred. Quin 2 was used to measure the free [Ca2+] of intact and permeable cells; PRL secretion at a free [Ca2+] corresponding to resting cytoplasmic [Ca2+] was 10% of maximal, while secretion at the [Ca2+] corresponding to the Ca2+ spike induced by thyrotropin-releasing hormone was approximately 25% of maximal.
我们使用经电场放电通透处理的GH3细胞，来研究钙离子（Ca2+）和蛋白激酶C激活剂（佛波酯和二酰基甘油）对催乳素（PRL）释放的影响。发现Ca2+在3微摩尔浓度时可刺激PRL释放约4倍，在约0.5微摩尔估计游离Ca2+时达到最大反应的一半。12 - O - 十四烷酰佛波醇 - 13 - 乙酸酯和1 - 油酰基 - 2 - 乙酰基 - sn - 甘油在一系列Ca2+浓度（1纳摩尔至3微摩尔）范围内均刺激PRL释放，但在较高Ca2+浓度（0.1微摩尔至1微摩尔）时刺激作用更强。两种试剂均使分泌达到最大刺激一半时的表观[Ca2+]降低了1.8倍。使用喹啉 - 2来测量完整细胞和通透细胞的游离[Ca2+]；对应静息细胞质[Ca2+]的游离[Ca2+]时的PRL分泌为最大值的10%，而对应促甲状腺激素释放激素诱导的Ca2+峰值的[Ca2+]时的分泌约为最大值的25%。
