[The role of GTP-binding proteins in regulating the activation of Na+/H+-exchange and Na+, K+, 2Cl- cotransport: effect of fluoride ion].
The effects of NaF and AlCl3 on basal and stimulated by hyperosmotic shock activities of Na+/H(+)-exchange and Na+, K+, 2Cl(-)-cotransport in rat smooth muscle and red blood cells have been studied. Preincubation of cells with 10 mM NaF leads to inhibition of basal and hyperosmotic shock-activated Na+, K+, 2Cl(-)-cotransport in smooth muscle cells--by 45% and 190%, respectively. Sodium fluoride causes 80% activation of basal Na+, K+, 2Cl(-)-cotransport in red blood cells with no effect on the transport induced by hyperosmotic shock. The effect of NaF on Na+, K+, 2Cl(-)-cotransport in red blood cells does not depend on Al3+. Basal Na+/H(+)-exchange is stimulated by NaF by 780% in smooth muscle cells and is insensitive to the fluoride in red blood cells. Under hyperosmotic conditions NaF activates Na+/H(+)-exchange by 100% in smooth muscle cells and by 130% in red blood cells; in the latter case its effect is potentiated by Al3+. The data obtained suggest that GTP-binding proteins are involved in the activation of Na+/H(+)-exchange under hyperosmotic conditions.
Kolosova
I A
IA
Bernkhard
I
I
Orlov
S N
SN
Biuller
F R
FR
D000818:Animals; D002352:Carrier Proteins / Q000187:drug effects / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D012964:Sodium / Q000378:metabolism*; D012969:Sodium Fluoride / Q000494:pharmacology*; D028021:Sodium-Potassium-Chloride Symporters
D002352:Carrier Proteins; D002712:Chlorides; D028021:Sodium-Potassium-Chloride Symporters; D012969:Sodium Fluoride; D012964:Sodium; D019204:GTP-Binding Proteins; D011188:Potassium
Rol' GTP-sviazyvaiushchikh belkov v reguliatsii aktivatsii Na+/H+-obmena i Na+, K+, 2Cl- kotransporta: deĭstvie ftorid-iona.