Diazepam decreases the response to the electrical stimulation of the nerve-skin preparation of the toad Caudiverbera caudiverbera.
1. The effect of diazepam was examined in the nerve skin preparation of the toad Caudiverbera caudiverbera. 2. Nerve stimulation was followed immediately by a transient increase in short-circuit current (SCC) and in the potential difference (PD), which consisted of a rapid and then a slow component. 3. Diazepam concentrations from 5.0 x 10(-5)M to 5.1 x 10(-4)M caused a dose-dependent block of both components to a 30% of their control values and also reduced the stimulatory responses to noradrenaline in this preparation. 4. Diazepam antagonized the potassium blocking effect of barium. 5. These results, based on electrophysiological and pharmacological evidence, are consistent with a calcium and sodium blocking effect of diazepam on the nerve skin junction of C. caudiverbera.
Norris
B
B
Department of Physiology, University of Concepción, Chile.
Nunez
G
G
Contreras
G
G
Contreras
E
E
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D001001:Anura; D001464:Barium / Q000037:antagonists & inhibitors; D003975:Diazepam / Q000494:pharmacology*; D004558:Electric Stimulation; D018757:GABA Modulators / Q000494:pharmacology*; D005712:Galvanic Skin Response / Q000187:drug effects*; D017136:Ion Transport / Q000187:drug effects; D009638:Norepinephrine / Q000037:antagonists & inhibitors; D015221:Potassium Channels / Q000187:drug effects*; D012867:Skin / Q000294:innervation*
D000316:Adrenergic alpha-Agonists; D018757:GABA Modulators; D015221:Potassium Channels; D001464:Barium; D003975:Diazepam; D009638:Norepinephrine