Role of protein kinase C in calcium sensitization during muscarinic stimulation in airway smooth muscle

Academic Article

Abstract

  • Muscarinie receptor stimulation increases Ca2+ sensitivity, i.e., the amount of force produced at a constant submaximal cytosolic Ca2+ concentration ([Ca2+](i)), in permeabilized smooth muscle preparations. It is controversial whether this increase in Ca2+ sensitivity is in part mediated by protein kinase C (PKC). With the use of a β-escin permeabilized canine tracheal smooth muscle (CTSM) preparation, the effect of four putative PKC inhibitors [calphostin C, chelerythrine chloride, a pseudosubstrate inhibitor for PKC [PKC peptide-(19-31)], and staurosporine) on Ca2+ sensitization induced by acetylcholine (ACh) plus GTP was determined. Proincubation with each of the inhibitors did not effect subsequent Ca2+ sensitization induced by muscarinic receptor stimulation in the presence of a constant submaximal [Ca2+](i), neither did any of these compounds reverse the increase in Ca2+ sensitivity induced by ACh plus GTP. Administration of a 1,2-diacylglycerol analog, 1-oleoyl-2-acetyl-sn-glycerol, did not induce Ca2+ sensitization at a constant submaximal [Ca2+](i). Thus we found no evidence that PKC mediates increases in Ca2+ sensitivity produced by muscarinic receptor stimulation in permeabilized CTSM.
  • Authors

    Digital Object Identifier (doi)

    Author List

  • Bremerich DH; Warner DO; Lorenz RR; Shumway R; Jones KA
  • Volume

  • 273
  • Issue

  • 4 17-4