Single administration - 60 mg

Experiments were performed at 37C on small bundles (5- 15 fibers) isolated from sealeus nrauscles of female Wistar rats. Before each set of experiments, the preparations were stimulated in the control solution during 20 min or more tea check for viability (those bundles exhibiting progressive decrease in twitch amplitude were discarded). Caffeine contrackres were elicited by application of caffeine added to the bathing medium to give a final concentration of 6 mkM. Such a caffeine concentration permitted repetitive contractures without damaging fibers After the initial equilibrating perid, the sensitivity of bundles for 6 mkM caffeine was checked two times, separated by a 30-min interval in which caffeine was absent. Only bundles that exhibited two successive contractures of equal amplitude were further tested with LCB29 (Idrocilamide).