[Inhibition, by an amphiphilic substance, niflumic acid, of the inward rectification of the crustacean muscle fiber].
Agents such as TEA+ or CS+ ions, these last ions instead of K+ ions in poor K extracellular solution, known to reduce or abolish the inwardly rectifying channel in many preparations produced no effect in crayfish muscle membrane By contrast, poor Cl extracellular solution (Cl- ions were replaced by CH3OSO3- ions) blocked the inward current activated by hyperpolarizing pulses and produced an increase of the resting potential. Niflumic acid is a agent which inhibited the inward going rectification of the crayfish muscle membrane. Apparent dissociation constant of niflumic acid with membrane sites was equal to about 6 X 10(-8) M; this value corresponds to that given by Cousin & Motais (1979) concerning translocation of Cl- ions in the membrane of red cells. Activation of the inward going rectification in the crayfish membrane is responsible of an inward current carried by Cl- ions.
D000818:Animals; D003400:Astacoidea / Q000502:physiology*; D002712:Chlorides / Q000008:administration & dosage / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects; D008566:Membranes / Q000502:physiology; D008839:Microelectrodes; D009132:Muscles / Q000502:physiology*; D009539:Nicotinic Acids / Q000494:pharmacology*; D009544:Niflumic Acid / Q000494:pharmacology*; D011188:Potassium / Q000008:administration & dosage
D002712:Chlorides; D009539:Nicotinic Acids; D009544:Niflumic Acid; D011188:Potassium
Inhibition par une substance amphiphile, l'acide niflumique, de la rectification dans le sens entrant de la fibre musculaire de Crustacé.