EFFECTS OF LOW BAROMETRIC PRESSURE ON THE CHEMICAL COMPOSITION OF THE ADRENAL GLANDS AND BLOOD OF RATS1

Abstract

The cholesterol content of the adrenal glands of rats exposed to varying degrees of anoxia for 5 hrs. diminished in a curvilinear fashion with increase in altitude up to 25,000 feet. The mean sea level control value was 5.48%, whereas the value at 25,000 ft. was 2.46%. At 28,000 feet, however, the detd. point failed to conform to the previously established curve. Simultaneous studies of adrenal ascorbic acid content, plasma cholesterol, plasma amino acid N, blood lactate and blood glucose concs. revealed small but progressive deviations from the sea level values up to 25,000 ft. The interval between 25,000 and 28,000 ft. was characterized by more striking changes in the concs. of most of the substances studied. The simulated altitude at which these abrupt changes were seen is often given as the survival ceiling.