Distribution of receptors mediating phosphoinositide hydrolysis in cultured human umbilical artery smooth muscle and endothelial cells

摘要: Abstract Cultures of human umbilical artery smooth muscle and endothelial cells have been established the effect a range calcium-mobilizing receptor agonists on inositol phospholipid hydrolysis has compared in two cell types. In cells, histamine (EC 50 20 μM), ATP 6.7 sodium fluoride (20 mM) thrombin (1 U/mL) produced marked increases [ 3 H]inositol phosphate accumulation. contrast, bradykinin 5-hydroxytryptamine (5-HT) (0.1 carbachol only small ( accumulation these cells. 16 (ec 4.5 nM), 5-HT 0.7 μM) 21 substantial effects (> 20% response to 1 mM histamine) while were much less effective. The both was antagonized by nM mepyramine (apparent K d = 5.6 2.9 types, respectively). ketanserin nM). 4-diphenylacetoxy- N -methylpiperidine (4-DAMP; p 9.3), atropine (p 9.7), pirenzepine 6.7) methoctramine 6.9). These data are consistent with involvement an M -muscarinic this response. studies suggest that receptors mediating differentially distributed betwen