Accession Number : ADA140289

Title :   Pulmonary Adaptation to High Altitude.

Descriptive Note : Annual summary rept. 1 Jan 79-1 Apr 80,


Personal Author(s) : Dempsey,J A

PDF Url : ADA140289

Report Date : Apr 1980

Pagination or Media Count : 20

Abstract : The work was aimed at defining the effects of hypoxia on various aspects of brain metabolism and their relationship to ventilatory regulation and to describing the effects of hypoxic acclimatization on ventilatory regulation during sleep. Brain tissue pH (in 2 to 4 regions) is closely regulated during chronic hypoxia, with time-dependent changes in brain lactic acid forming the major contribution to this regulation. Cortex and brain stem lactic acid concentrations peak in acute hypoxia, decrease gradually with time, but show minimal reduction when acute normoxia is restored in the acclimatized animal. These data suggest that brain alkalosis is the key determinant of these lactate changes and that lactate production (and supposedly brain ECF acidification) is not positively correlated with ventilatory acclimatization. Significant effects of hypoxia on monoamine metabolism--level and turnover--were observed in both carotid body and the CNS, and significant adaptive effects were evident with duration of hypoxia. Pharmacologically induced changes in CNS serotonin metabolism had significant effects on normal ventilatory control, but manipulation of CNS catecholamines had no effect on ventilatory control or acclimatization.

Descriptors :   *Adaptation(Physiology), *Pulmonary function, *Acclimatization, High altitude, Respiration, Brain, Metabolism, Hypoxia, Central nervous system, Lactic acid, Lactates, Serotonin, Catecholamines, pH factor

Subject Categories : Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE