Hawley J, Rubin P C, Hill S J
Department of Physiology & Pharmacology, Medical School, Queen's Medical Centre, Nottingham, U.K.
Biochem Pharmacol. 1995 Mar 30;49(7):1005-11. doi: 10.1016/0006-2952(94)00459-y.
Cultures of human umbilical artery smooth muscle and endothelial cells have been established and the effect of a range of calcium-mobilizing receptor agonists on inositol phospholipid hydrolysis has been compared in the two cell types. In human umbilical artery endothelial cells, histamine (EC50 20 microM), ATP (EC50 6.7 microM), sodium fluoride (20 mM) and thrombin (1 U/mL) produced marked increases in [3H]inositol phosphate accumulation. In contrast, bradykinin (1 microM), 5-hydroxytryptamine (5-HT) (0.1 mM) and carbachol (1 mM) produced only a small (< 1% of the response to 1 mM histamine) effect on [3H]inositol phosphate accumulation in these cells. In human umbilical artery smooth muscle cells, histamine (EC50 16 microM), bradykinin (EC50 4.5 nM), 5-HT (EC50 0.7 microM) and carbachol (EC50 21 microM) produced substantial effects (> 20% of the response to 1 mM histamine) on inositol phospholipid hydrolysis while ATP (1 mM) and thrombin (1 U/mL) were much less effective. The response to histamine in both smooth muscle and endothelial cells was antagonized by 50 nM mepyramine (apparent Kd = 5.6 and 2.9 nM in the two cell types, respectively). The response to 5-HT in smooth muscle cells was antagonized by 50 nM ketanserin (apparent Kd = 4.5 nM). In human umbilical artery smooth muscle cells the inositol phosphate response to carbachol was antagonized by 4-diphenylacetoxy-N-methylpiperidine (4-DAMP; pKd = 9.3), atropine (pKd = 9.7), pirenzepine (pKd = 6.7) and methoctramine (pKd = 6.9). These data are consistent with the involvement of an M3-muscarinic receptor in this response. These studies suggest that receptors mediating inositol phospholipid hydrolysis are differentially distributed between human umbilical artery endothelial and smooth muscle cells.
已建立人脐动脉平滑肌细胞和内皮细胞培养体系，并比较了一系列钙动员受体激动剂对这两种细胞类型中肌醇磷脂水解的影响。在人脐动脉内皮细胞中，组胺（EC50为20 μM）、ATP（EC50为6.7 μM）、氟化钠（20 mM）和凝血酶（1 U/mL）可使[3H]肌醇磷酸积累显著增加。相比之下，缓激肽（1 μM）、5-羟色胺（5-HT）（0.1 mM）和卡巴胆碱（1 mM）对这些细胞中[3H]肌醇磷酸积累的影响很小（<对1 mM组胺反应的1%）。在人脐动脉平滑肌细胞中，组胺（EC50为16 μM）、缓激肽（EC50为4.5 nM）、5-HT（EC50为0.7 μM）和卡巴胆碱（EC50为21 μM）对肌醇磷脂水解有显著影响（>对1 mM组胺反应的20%），而ATP（1 mM）和凝血酶（1 U/mL）的作用则小得多。50 nM的美吡拉敏可拮抗平滑肌细胞和内皮细胞对组胺的反应（在两种细胞类型中，表观Kd分别为5.6 nM和2.9 nM）。50 nM的酮色林可拮抗平滑肌细胞对5-HT的反应（表观Kd = 4.5 nM）。在人脐动脉平滑肌细胞中，4-二苯基乙酰氧基-N-甲基哌啶（4-DAMP；pKd = 9.3）、阿托品（pKd = 9.7）、哌仑西平（pKd = 6.7）和甲溴东莨菪碱（pKd = 6.9）可拮抗对卡巴胆碱的肌醇磷酸反应。这些数据与M3型毒蕈碱受体参与此反应一致。这些研究表明，介导肌醇磷脂水解的受体在人脐动脉内皮细胞和平滑肌细胞之间分布不同。
