D-AMPHETAMINE MORTALITY AND RELATED LEVELS IN TISSUE OF RATS EXPOSED TO ALTITUDE.

Two groups of Sprague-Dawley rats were injected with d-amphetamine sulfate and the number of dead animals was recorded after 2 hours. One group of rats was exposed to a simulated altitude of 12,000 ft. in a low-pressure chamber for 1 hour the other, the control group, was observed at ground level for the 2-hour duration. After an approximate LD50 dosage of d-amphetamine sulfate 20 mg.kg. was established at ground level, three dose levels were administered within each group--10 mg. kg., 15 mg. kg., and 20 mg. kg. Mortality observed in the altitude group was approximately one-third greater than that in the control group. Doses which showed equivalent mortality were then administered to separate groups--10 mg. kg. to an altitude group and 20 mg. kg. to a ground-level group. A combination of labeled 14C-d-amphetamine and unlabeled amphetamine sulfate was used. The data suggest that the potency of amphetamine increases at altitude, and that the difference in mortality may be due to mechanisms dependent on tissue concentration of amphetamine. Author