Roles of inhibitors of myosin light chain kinase and tyrosine kinase on cation influx in agonist-stimulated endothelial cells

Biochem Biophys Res Commun. 1997 Jun 27;235(3):657-62. doi: 10.1006/bbrc.1997.6856.


Agonist-stimulated Ca2+ influx is critically important to mediate the function of endothelial cells. It has been suggested that release of Ca2+ from internal stores activates Ca2+ influx across the plasma membrane. In the present study, we investigated the effects of ML-9, a myosin light-chain kinase (MLCK) inhibitor, and genistein, a tyrosine kinase inhibitor, on the agonist stimulated Ca2+ response in porcine aortic endothelial cells loaded with a Ca2+-sensitive dye, fura-2. ML-9 almost completely abolished Ca2+ influx, whereas genistein only partially attenuated Ca2+ entry. Both of them did not affect the mobilization of Ca2+ from internal stores. In contrast, genistein was more potent in the inhibition of Mn2+ influx than ML-9. These findings indicate the different selectivity for Ca2+ and Mn2+ in the cation entry pathway in agonist-stimulated endothelial cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aorta
  • Azepines / pharmacology*
  • Bradykinin / pharmacology
  • Calcium / metabolism*
  • Cations, Divalent / metabolism
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Cells, Cultured
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / metabolism*
  • Enzyme Inhibitors / pharmacology*
  • Fluorescent Dyes
  • Fura-2 / analogs & derivatives
  • Genistein
  • Isoflavones / pharmacology*
  • Kinetics
  • Manganese / metabolism*
  • Myosin-Light-Chain Kinase / antagonists & inhibitors*
  • Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Swine
  • Thapsigargin / pharmacology


  • Azepines
  • Cations, Divalent
  • Enzyme Inhibitors
  • Fluorescent Dyes
  • Isoflavones
  • fura-2-am
  • ML 9
  • Manganese
  • Thapsigargin
  • Genistein
  • Protein-Tyrosine Kinases
  • Myosin-Light-Chain Kinase
  • Bradykinin
  • Calcium
  • Fura-2