Comparison of cation transport and regulatory volume decrease between red blood cells from the japanese black bear and the dog

Autor: T. Nakayama, T. Komatsu, Hiroshi Fujise, T. Tsubota, N. Iwase
Rok vydání: 2003
Předmět:
Zdroj: Comparative Clinical Pathology. 12:33-39
ISSN: 1618-565X
1618-5641
Popis: Cation transport and regulatory volume decrease (RVD) were investigated in the red blood cells (RBC) of the Japanese black bear and compared with that of the normal dog (LK dog), which possesses RBC with high sodium (Na) and low potassium (K). Unlike the RBC of the American black bear, RBC from the Japanese black bear failed to exhibit K congener rubidium (Rb) influxes through Na–K pump and K-chloride (Cl) cotransport. In the RBC of the Japanese black bear, treatment with N-ethyl maleimide (NEM), calcium (Ca) ionophore A23187 and EGTA, and hyposmotic medium failed to elicit K–Cl cotransport, whereas these perturbations elicited K–Cl cotransport in the LK dog RBC. The Ca uptake was measured in RBC of both the Japanese black bear and the LK dog, and the fluxes were enhanced in hyposmotic medium and inhibited with quinidine, an inhibitor of Na/Ca exchange transporter. Extracellular Ca-dependent Na efflux was detected in RBC of both the Japanese black bear and the LK dog, and it was also inhibited with quinidine. The Ca uptake and Na efflux were probably mediated by Na/Ca exchange transporter. RBC of both the Japanese black bear and the LK dog were restored to their original volume after being swollen in hyposmotic medium with, but not without, Ca. Thus, Na/Ca exchange transporter causes regulatory volume decrease in the RBC of both the Japanese black bear and the LK dog.
Databáze: OpenAIRE
Externí odkaz: