Accession Number : AD0784510

Title :   Excretion of Lactic Acid by Rats Exposed to Simulated High Altitude.

Descriptive Note : Research rept.,

Corporate Author : DEFENCE AND CIVIL INST OF ENVIRONMENTAL MEDICINE DOWNSVIEW (ONTARIO)

Personal Author(s) : Myles,W. S. ; Radomski,M. W.

Report Date : 1974

Pagination or Media Count : 4

Abstract : Plasma and urinary levels of lactic acid were measured in rats exposed to simulated altitudes of 18,000, 24,000 and 26,000 ft for six hr periods. Acute exposure (six hr) to 18,000 ft. did not alter the basal level of lactic acid excretion but 5-fold and 50-fold increases were found in animals after six hr at 24,000 and 26,000 ft, respectively. A large interindividual variability in lactic acid excretion was observed at 24,000 and 26,000 ft with values ranging from 4 to 1,000mg/25mg urinary creatinine. Injection of adrenalin increased urinary lactate levels at altitude whereas prior fasting eliminated altitude-induced increases in lactic acid. It is suggested that at altitude, lactic acid formation from liver glycogen is, in part, mediated by increased adrenalin secretion and that when blood lactate exceeds a critical level (14 - 19mg percent), lactic acid increases in the urine. (Modified author abstract)

Descriptors :   *Excretion, *High altitude, *Lactic acid, *Stress(Physiology), Rats, Experimental data, Canada

Subject Categories : Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE