DISTRIBUTION OF THE ANESTHETIC GAS XENON IN DOG TISSUES AS DETERMINED WITH RADIOACTIVE XENON

¹ Department of Pharmacology and the Division of Anesthesiology of the Department of Surgery, College of Medicine, State University of Iowa, Iowa City, and the Medical Department, Brookhaven National Laboratory, Upton, New York

Radioactive xenon has been employed to study the distribution of this anesthetic gas among 21 tissues of 7 dogs. Procedures for the preparation, handling, and measurement of radioactive xenon in small samples of mammalian tissues are described. The adrenal gland was shown to contain 155 per cent (dry weight basis; 224 per cent on a wet weight basis) as much xenon as any one of five brain tissues (cerebral cortex, caudate nucleus, thalamus, hypothalamus and medulla oblongata) or kidney, among which there were not significantly different amounts of xenon. The amounts of xenon (37°C.) per mgm. of adrenal gland were 1.15 cmm. dry weight basis, and 0.414 cmm. wet weight basis. Liver and spleen (and possibly blood) contained approximately 58 per cent as much xenon as brain tissues (68 per cent, wet basis), while approximately 28 per cent as much as in brain was found in striated muscle (32 per cent, wet basis) and perirenal fat (100 per cent, wet basis). With less assurance of the percentages cited, the testes were found to contain on a dry weight basis 100 per cent per mgm. as much as brain; heart and thyroid, 80 per cent; pancreas, 63 per cent; ovary, 45 per cent; skin, 34 per cent; other depot fat, 25 per cent. Traces were found in bone, tooth pulp and urine.