Evidence for the involvement of G proteins in the modulation of 22Na and 45Ca fluxes in myogenic L6 and aortic smooth muscle cells.
Preincubation of rat skeletal muscle derived L6 myoblasts with 10 mM NaF increased, the activity of Na+/H+ exchanger, and the uptake of 45Ca by 2 and 5 folds, respectively. In cultured vascular smooth muscle cells (CVSMC) of rat aorta, NaF increased the activity of Na+,K(+)-pump, Na+/H+ exchanger, passive permeability for Na+, and 45Ca uptake by 1.6, 9, 2, and 9 folds, respectively. Both, in CVSMC and L6 cells, the effect of NaF on the Na+/H+ exchanger and 45Ca uptake were significantly augmented by 20 microM AlCl3. No effect of AlCl3 on the NaF dependent changes in ion flux was seen in rat erythrocytes. The results suggest that in L6 and CVSMC cells, the Na+/H+ exchanger and Ca++ uptake pathway(s) are activated by GTP-binding proteins.
Orlov
S N
SN
Laboratory of Physical Chemistry of Biomembranes, Moscow State University, Russia.
Sen
C K
CK
Kolosova
I A
IA
Bernhardt
J
J
Hänninen
O
O
Bühler
F R
FR
D000535:Aluminum / Q000494:pharmacology; D000077410:Aluminum Chloride; D017607:Aluminum Compounds; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000502:physiology*; D002478:Cells, Cultured; D002712:Chlorides / Q000494:pharmacology; D004912:Erythrocytes / Q000502:physiology; D019204:GTP-Binding Proteins / Q000502:physiology*; D066298:In Vitro Techniques; D009131:Muscle, Smooth, Vascular / Q000502:physiology; D009132:Muscles / Q000502:physiology*; D051381:Rats; D012413:Rubidium / Q000378:metabolism*; D012964:Sodium / Q000502:physiology*; D012969:Sodium Fluoride / Q000494:pharmacology
D017607:Aluminum Compounds; D002712:Chlorides; D000077410:Aluminum Chloride; D012969:Sodium Fluoride; D012964:Sodium; D000535:Aluminum; D019204:GTP-Binding Proteins; D012413:Rubidium; D002118:Calcium