Myers C L, Lazo J S, Pitt B R
Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut 06510.
Am J Physiol. 1989 Oct;257(4 Pt 1):L253-8. doi: 10.1152/ajplung.1989.257.4.L253.
Acute exposure (30 min-1 h) of bovine pulmonary artery endothelial cells in culture (BPAEC) to phorbol myristate acetate (PMA 10(-10)-10(-6) M) resulted in concentration-dependent decrement in serotonin (5-HT) uptake. Neither cell viability (trypan blue exclusion or release of deoxyglucose) nor activity of another plasma membrane function, angiotensin-converting enzyme activity, were affected. A decrease in 5-HT uptake was also noted with phorbol 12,13 dibutyrate and mezerein, but not with 4-alpha-phorbol 12,13 didecanoate, which does not stimulate protein kinase C (PKC). Inhibition of 5-HT uptake by PMA (160 nM) was reversed in a concentration-dependent manner by pretreatment of cells with the PKC inhibitor staurosporine (3-100 nM). BPAEC were treated with PMA (160 nM) for 1 h, and activities of PKC in cytosolic and membrane compartments were determined. PMA did not significantly affect total cellular PKC activity but resulted in a translocation of activity from cytosol to membrane (control membrane activity 67 +/- 4%; PMA-treated membrane activity 97 +/- 1% of total cellular PKC). Thus we propose that translocation of PKC from cytosol to membrane results in inhibition of 5-HT uptake by BPAEC.
将培养的牛肺动脉内皮细胞（BPAEC）急性暴露（30分钟 - 1小时）于佛波酯肉豆蔻酸酯乙酸酯（PMA，10⁻¹⁰ - 10⁻⁶ M）会导致血清素（5 - HT）摄取呈浓度依赖性下降。细胞活力（台盼蓝排斥试验或脱氧葡萄糖释放）以及另一种质膜功能——血管紧张素转换酶活性均未受到影响。佛波醇12,13 - 二丁酸酯和大戟二萜醇也会导致5 - HT摄取减少，但4 - α - 佛波醇12,13 - 二癸酸酯不会，后者不会刺激蛋白激酶C（PKC）。用PKC抑制剂星形孢菌素（3 - 100 nM）预处理细胞后，PMA（160 nM）对5 - HT摄取的抑制作用以浓度依赖性方式被逆转。用PMA（160 nM）处理BPAEC 1小时，然后测定胞质和膜部分的PKC活性。PMA对细胞总PKC活性没有显著影响，但导致活性从胞质转移至膜（对照膜活性为67±4%；PMA处理后的膜活性为细胞总PKC的97±1%）。因此我们认为，PKC从胞质转移至膜会导致BPAEC对5 - HT摄取的抑制。
