Involvement of Rho-kinase and tyrosine kinase in hypotonic stress-induced ATP release in bovine aortic endothelial cells.
Hypotonic stress induces ATP release followed by Ca2+ oscillations in bovine aortic endothelial cells (BAECs). We have investigated the cellular mechanism of the hypotonic stress-induced ATP release. Hypotonic stress induced tyrosine phosphorylation of at least two proteins, of 110 and 150 kDa. Inhibition of tyrosine kinase by the tyrosine kinase inhibitors herbimycin A and tyrphostin 46 prevented ATP release and ATP-mediated Ca2+ oscillations induced by hypotonic stress. ATP release was also inhibited by the pretreatment of the cells with botulinum toxin C3, and augmented by lysophosphatidic acid. Furthermore, pre-treating the cells with Y-27632, a selective inhibitor of Rho-kinase, also suppressed the hypotonic stress-induced ATP release and Ca2+ oscillations, indicating that Rho-mediated activation of Rho-kinase may be involved in the hypotonic ATP release. Hypotonic stress also induced a transient rearrangement of the actin cytoskeleton, which was suppressed by the tyrosine kinase inhibitors Y-27632 and cytochalasin B. However, pretreatment of the cell with cytochalasin B inhibited neither the hypotonic stress-induced ATP release nor the Ca2+ oscillations. These results indicate that tyrosine kinase and the Rho-Rho-kinase pathways are involved in hypotonic stress-induced ATP release and actin rearrangement, but actin polymerization is not required for ATP release in BAECs.
Koyama
T
T
Department of Pharmacology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
Oike
M
M
Ito
Y
Y
D000199:Actins / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000577:Amides / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000166:cytology; D016227:Benzoquinones; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D002417:Cattle; D002478:Cells, Cultured; D003571:Cytochalasin B / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007038:Hypotonic Solutions / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D047029:Lactams, Macrocyclic; D009997:Osmotic Pressure; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011725:Pyridines / Q000494:pharmacology; D011809:Quinones / Q000494:pharmacology; D017828:Rifabutin / Q000031:analogs & derivatives; D022502:Stress Fibers / Q000378:metabolism; D054460:rho-Associated Kinases
D000199:Actins; D000577:Amides; D016227:Benzoquinones; D004791:Enzyme Inhibitors; D007038:Hypotonic Solutions; D047908:Intracellular Signaling Peptides and Proteins; D047029:Lactams, Macrocyclic; D011725:Pyridines; D011809:Quinones; C108830:Y 27632; D017828:Rifabutin; D003571:Cytochalasin B; C020754:herbimycin; D000255:Adenosine Triphosphate; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases