The action of the peptidoleukotriene LTD4 on intracellular calcium in rat mesangial cells.
The dose-dependent effect of CGP 45715A on the LTD4-induced Ca2+ response of glomerular mesangial cells has been studied. Our results demonstrate that the LTD4-dependent increase in the cytosolic Ca2+ concentration primarily involves an InsP3-mediated release of Ca2+ from intracellular storage sites and to a minor extent an enhanced influx of Ca2+ through receptor-operated Ca2+ channels located in the plasma membrane. The action of CGP 45715A on the Ca2+ response is an inhibitory one and is convincingly explained by a displacement of LTD4 from its receptor site(s). The contractile effect of LTD4 on pulmonary smooth muscle is proposed to be mainly caused by a receptor-mediated hydrolysis of phosphatidylinositol-4,5-bisphosphate.
Ochsner
M
M
Ciba-Geigy Ltd., Physics Department, Basle, Switzerland.
D000818:Animals; D001578:Benzopyrans / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D005920:Glomerular Mesangium / Q000378:metabolism*; D017998:Leukotriene D4 / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008954:Models, Biological; D009130:Muscle, Smooth / Q000187:drug effects; D010716:Phosphatidylinositols / Q000502:physiology; D051381:Rats; D015398:Signal Transduction
D001578:Benzopyrans; D010716:Phosphatidylinositols; D017998:Leukotriene D4; C067425:iralukast; D002118:Calcium