The response of regional circulation to reduced body temperature was studied in the white laboratory rat Rattus rattus, using injected 22Na as a tracer. Observations made on equilibration of plasma and tissue radiosodium, in normo- and hypothermic animals, provided evidence as to possible mechanisms responsible for transport of sodium at this interface. Evidence is also presented as to disposition of sodium in tissues during the first biological half-life.
Circulation to the peritoneal cavity is reduced to 50%, and to skin and bone approximately 10% and 25% of normothermic values respectively at body temperatures of 16-18 C. The appearance of radiosodium in the heart and lungs is dependent upon circulation to the site of injection.
Equilibration of plasma and tissue radiosodium in normothermic animals occurs within 1 hr of injection in all tissues except brain, femur, and spleen, which require up to 12 hr. Transport of sodium between plasma and tissues appears to be affected primarily by diffusion or some related physical process.
Level of Degree
UNM Biology Department
First Committee Member (Chair)
Marvin LeRoy Riedesel
Second Committee Member
Gordon Verle Johnson
Third Committee Member
Danforth, David N. Jr.. "Studies Of Sodium-22 Distribution During Hypothermia In Rattus Rattus." (1967). https://digitalrepository.unm.edu/biol_etds/408