Temperature adaptation of active sodium-potassium transport and of passive permeability in erythrocytes of ground squirrels.
J Gen Physiol
; 58(6): 634-49, 1971 Dec.
Article
em En
| MEDLINE
| ID: mdl-5120391
ABSTRACT
Unidirectional active and passive fluxes of (42)K and (24)Na were measured in red blood cells of ground squirrels (hibernators) and guinea pigs (nonhibernators). As temperature is lowered, "active" (ouabain-sensitive) K influx and Na efflux were more greatly diminished in guinea pig cells than in those of ground squirrels. The fraction of total K influx which is ouabain sensitive in red blood cells of ground squirrels was virtually constant at all temperatures, whereas it decreased abruptly in guinea pig cells as temperature was lowered. All the passive fluxes (i.e., Na influx, K efflux, and ouabain-insensitive K influx and Na efflux) decreased logarithmically with decrease in temperature in both species, but in ground squirrels the temperature dependence (Q(10) 2.5-3.0) was greater than in guinea pig (Q(10) 1.6-1.9). Thus, red blood cells of ground squirrel are able to resist loss of K and gain of Na at low temperature both because of relatively greater Na-K transport (than in cells of nonhibernators) and because of reduced passive leakage of ions.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potássio
/
Sódio
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Permeabilidade da Membrana Celular
/
Eritrócitos
Limite:
Animals
Idioma:
En
Revista:
J Gen Physiol
Ano de publicação:
1971
Tipo de documento:
Article