Effect of methylchloroform inhalation on barbiturate hypnosis and hepatic drug metabolism in male mice

Abstract

A 24-hr inhalation of methylchloroform by male mice reduced hexobarbital hypnosis but had no effect on hypnosis produced by barbital or chloral hydrate. The maximum reduction in hypnosis occurred at 24 hr after the termination of inhalation, and the hypnosis returned to the control level at 48 hr after the termination of inhalation. The effect of repeated short exposures, 4 or 8 hr/day for several days, had a cumulative effect, but a single 8-hr exposure was without effect on hexobarbital hypnosis in male mice. The supernatant fractiob isolated (centrifuging homogenates at 9000 g) from livers of male mice previously exposed to methylchloroform vapor oxidized hexobarbital more efficiently, but its ability to reduce p-nitrobenzoic acid remained unaffected. The protein content of this liver supernatant fraction also was not altered after exposure to methylchloroform.