A role for calcium in the acute and chronic actions of ethanol in vitro

Ethanol, in a concentration of 40--160 mM, depressed the electrically evoked contractions of the guinea-pig ileum longitudinal muscle/myenteric plexus (LM/MP) preparation in a dose-dependent manner. The acute ethanol inhibition in vitro was partially reversed by raising the extracellular calcium concentration. Following a 4 week ethanol treatment in vivo, by means of daily i.p. injections, the LM/MP preparation was rendered tolerant to ethanol and at the same time calcium was more effective in reversing the inhibitory effect of ethanol. It appears that calcium plays a role in the acute action of, and development of tolerance to, ethanol.