Stimulation of Na(+)-H+ exchange, the Na(+)-K+ pump and Na+,K+,Cl- cotransport by endothelin-1 in cultured vascular smooth muscle cells.
Endothelin-1 concentrations higher than 10(-10) mol/l were able to strongly stimulate Na(+)-H+ exchange, the Na(+)-K+ pump and the Na+,K+Cl- cotransport system in A10 vascular smooth muscle cells. The stimulation of Na(+)-H+ exchange was more marked in fresh than in H(+)-loaded cells, suggesting an increase in the apparent affinity for internal H+. Pump stimulation appeared to be secondary to sodium entry through Na(+)-H+ exchange because it was absent in (1) Na(+)-loaded cells and (2) in the presence of ethyl-isopropylamiloride (EIPA). Stimulation of cotransport was blocked by indomethacin, suggesting the involvement of a cyclo-oxygenase product. In conclusion, the action of endothelin-1 in vascular smooth muscle induces the onset of negative feedback mechanisms which enhance the ability of the vascular cells to regulate disturbances in Na+,K+ and Cl- contents.
Rosati
C
C
INSERM U 7/CNRS UA 318, Hôpital Necker, Paris, France.
Jeanclos
E
E
Nazaret
C
C
Chabrier
P E
PE
Hannaert
P
P
Braquet
P
P
Garay
R
R
D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D002460:Cell Line / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D002713:Chlorine / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D016232:Endothelins; D004730:Endothelium, Vascular / Q000502:physiology*; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D010455:Peptides / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000187:drug effects* / Q000378:metabolism; D012964:Sodium / Q000378:metabolism*; D015222:Sodium Channels / Q000187:drug effects* / Q000378:metabolism; D013268:Stimulation, Chemical
D016232:Endothelins; D010455:Peptides; D015221:Potassium Channels; D015222:Sodium Channels; D002713:Chlorine; D012964:Sodium; D011188:Potassium