Accession Number : AD0434870

Title :   TRANSIENT CHANGES IN ARTERIAL LACTIC ACID OF DOGS AT 21,000 FEET,

Corporate Author : SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TEX

Personal Author(s) : Cain ,Stephen M. ; Dunn,James E. , II

Report Date : MAR 1964

Pagination or Media Count : 10

Abstract : After a 3-hour control period at ground level, unanesthetized dogs were exposed for 8 hours to 21,000 feet simulated altitude (Pb=335 mm. Hg). Arterial blood samples were djawn frequently from a Teflon T-cannula surgically placed in a cartoid artery 1 or 2 days prior to the experiment. Lactic and pyruvic acid concentrations, Pc02, P02, and pH were measured. At altitude, the average arterial P02 was 32 mm. Hg. Pc02 was 24 mm. Hg and pH was 7.50 mm. Hg. All control values fell in normal ranges. Althugh the magnitude of changes differed among animals, arterial lactic acid reached a peak value within the first 2 hours at altitude, gradually declining thereafter, and in most animals it closely approached the control value during the eighth hour at altitude. Excess lactate changed in a similar manner (with no concomitant relief of arterial hypoxia and hypocapnia). The decline in lactic acid remains unexplained. (Author)

Descriptors :   (*LACTIC ACID, BLOOD CIRCULATION), (*BLOOD CHEMISTRY, HIGH ALTITUDE), (*HIGH ALTITUDE, PHYSIOLOGY), PYRUVIC ACID, BICARBONATES, OXYGEN CONSUMPTION, HYPOXIA, DOGS, AVIATION MEDICINE

Distribution Statement : APPROVED FOR PUBLIC RELEASE