The effect of diphenylamine-2-carboxylate (DPC), a blocker of the Cl- conductance pathway in Cl- transporting epithelia, has been evaluated in-vitro on the electrophysiological variables of rat extensor digitorum longus muscle fibres. DPC (5-240 μM) caused a dose-related increase of membrane resistance which was attributed entirely to a fall in Cl- channel conductance (IC50, 120 μM), since potassium conductance was not affected by the treatment. DPC also modified fibre excitability. A significant dose-dependent increase was observed in the latency of the action potential and in the excitability of the membrane. DPC was less potent on striated fibres than anthracene-9-carboxylic acid, another specific blocker of C1- channel conductance. Moreover DPC was less potent on skeletal muscle than on C1- transporting epithelia. Morphological differences in the Cl- channels or of the drug binding sites may account for the differences between tissues.
The effect of diphenylamine-2-carboxylate on C1- channel conductance and on excitability characteristics of rat skeletal muscle
CONTE, Diana;DE LUCA, Annamaria;
1989-01-01
Abstract
The effect of diphenylamine-2-carboxylate (DPC), a blocker of the Cl- conductance pathway in Cl- transporting epithelia, has been evaluated in-vitro on the electrophysiological variables of rat extensor digitorum longus muscle fibres. DPC (5-240 μM) caused a dose-related increase of membrane resistance which was attributed entirely to a fall in Cl- channel conductance (IC50, 120 μM), since potassium conductance was not affected by the treatment. DPC also modified fibre excitability. A significant dose-dependent increase was observed in the latency of the action potential and in the excitability of the membrane. DPC was less potent on striated fibres than anthracene-9-carboxylic acid, another specific blocker of C1- channel conductance. Moreover DPC was less potent on skeletal muscle than on C1- transporting epithelia. Morphological differences in the Cl- channels or of the drug binding sites may account for the differences between tissues.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
