Harman I, Costello A, Ganong B, Bell R M, Handwerger S
Am J Physiol. 1986 Aug;251(2 Pt 1):E172-7. doi: 10.1152/ajpendo.1986.251.2.E172.
Activation of calcium-activated, phospholipid-dependent protein kinase C by diacylglycerol and phorbol esters has been shown to mediate release of hormones in many systems. To determine whether protein kinase C activation is also involved in the regulation of prolactin release from human decidua, we have examined the effects of various acylglycerols and phorbol esters on the synthesis and release of prolactin from cultured human decidual cells. sn-1,2-Dioctanoylglycerol (diC8), which is known to stimulate protein kinase C in other systems, inhibited prolactin release in a dose-dependent manner with maximal inhibition of 53.1% (P less than 0.01) at 100 microM. Diolein (100 microM), which also stimulates protein kinase C activity in some systems, inhibited prolactin release by 21.3% (P less than 0.05). Distearin and dipalmitin, which are much less effective in activating protein kinase C, and monopalmitin and tripalmitin, which do not activate protein kinase C, had no significant effect on prolactin release. Phorbol 12-myristate 13-acetate (PMA), phorbol 12,13-didecanoate, and 4 beta-phorbol 12,13-dibutyrate, which activate protein kinase C in other systems, also inhibited the release of prolactin, while the protein kinase C inactivate 4 alpha-phorbol-12,13-didecanoate was without effect. The inhibition of prolactin release was secondary to a decrease in prolactin synthesis. The amounts of prolactin synthesized by cells exposed to diC8 (300 microM) or PMA (10(-7) M) for 30 min were 56.3 and 50.0% less than that synthesized by control cells (P less than 0.01 in each instance).(ABSTRACT TRUNCATED AT 250 WORDS)
在许多系统中，二酰甘油和佛波酯可激活钙激活的、磷脂依赖性蛋白激酶C，进而介导激素释放。为了确定蛋白激酶C激活是否也参与人蜕膜催乳素释放的调节，我们研究了各种酰基甘油和佛波酯对培养的人蜕膜细胞催乳素合成和释放的影响。已知在其他系统中能刺激蛋白激酶C的sn-1,2-二辛酰甘油（二C8），以剂量依赖性方式抑制催乳素释放，在100微摩尔时最大抑制率为53.1%（P<0.01）。在某些系统中也能刺激蛋白激酶C活性的二油精（100微摩尔），抑制催乳素释放21.3%（P<0.05）。在激活蛋白激酶C方面效果差得多的二硬脂酸甘油酯和二棕榈酸甘油酯，以及不激活蛋白激酶C的单棕榈酸甘油酯和三棕榈酸甘油酯，对催乳素释放无显著影响。在其他系统中激活蛋白激酶C的佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）、佛波醇12,13-十二烷酸酯和4β-佛波醇12,13-二丁酸酯，也抑制催乳素释放，而蛋白激酶C失活剂4α-佛波醇-12,13-十二烷酸酯则无作用。催乳素释放的抑制是催乳素合成减少的继发结果。暴露于二C8（300微摩尔）或PMA（10^-7摩尔）30分钟的细胞合成的催乳素量，分别比对照细胞合成的量少56.3%和50.0%（每次P<0.01）。
