[The role of sodium-proton exchange in the regulation of the electric and contractile activity of smooth muscles].
The Na+/H+-exchange inhibitor aethylisopropylamyloride was found to enhance the membrane resistance, the AP duration, and the duration of the guinea pig ureter's smooth muscle contraction. Tetraethylammonium and incubation in the Ca-free EG-TA-containing solution eliminated the activating effect of this inhibitor. Gramycidin A shortens the AP plateau. The Na+/H+-exchange mechanism seems to act under normal conditions. Alterations occurring in electrical and contractile activities of smooth muscle under the effect of the Na+/H+-exchange seem to result from the changes in the membrane Ca-dependent potassium conductivity.
Baskakov
M B
MB
Siberian Medical University, Moscovsky Tract, 2, Tomsk 634050, Russia.
Kovalev
I V
IV
Kapilevich
L V
LV
Medvedev
M A
MA
D000200:Action Potentials / Q000187:drug effects; D000584:Amiloride / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002122:Calcium Chloride / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D006096:Gramicidin / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D011188:Potassium / Q000502:physiology; D011817:Rabbits; D017923:Sodium-Hydrogen Exchangers / Q000037:antagonists & inhibitors / Q000502:physiology*; D013621:Taenia; D014513:Ureter / Q000502:physiology
D017923:Sodium-Hydrogen Exchangers; D006096:Gramicidin; D000584:Amiloride; D002122:Calcium Chloride; D011188:Potassium; C039614:ethylisopropylamiloride