Accession Number : ADA331554

Title :   Membrane Transport: Cellular Probe of Heat Stroke.

Descriptive Note : Final rept. 2 Aug 93-1 Aug 97,

Corporate Author : GEORGIA UNIV ATHENS

Personal Author(s) : Willis, John S.

PDF Url : ADA331554

Report Date : SEP 1997

Pagination or Media Count : 66

Abstract : In vitro effects of temperature on permeation of Na+ and K+ were explored in red cells of guinea pig to evaluate the Energy Depletion Hypothesis of heatstroke. Prior to Midterm Report it was found that large changes in cell Na+ and K+ do not occur at 410C and 450C, that increase in pump activity matches elevated Na+ permeation at 410C and that steep rise in K-Cl cotransport at 410C and 450C accounts for most increase in passive K+ permeation. Since Midterm Report this large temperature effect on K-Cl cotransport has been shown to operate indirectly through regulation of the carrier, most probably the phosphates that activates it. Increased net loss of K+ through this pathway protects the cell from swelling at 410C and 450C. In vitro this loss is balanced by uptake of K+ through the Na-K pump, but if pumps are limited in vivo, it could account for hyperthermic hyperkalemia. Cell acidification (and swelling) causes an enormous increase in Na+ uptake at 410C and 450C through an unknown amiloride sensitive pathway. This devastating rise in Na permeation could, if general, meet the primary condition for cell failure postulated by the Energy Depletion Hypothesis.


Subject Categories : Medicine and Medical Research
      Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE