Kinetics of lithium efflux through the (Na,K)-pump of human erythrocytes.
Evidence from the kinetics of transport supports the hypothesis that cellular Li, Lic, interacts with the internal aspect of the (Na,K)-pump as a congener of Na, Lic and Nac compete for the same sites on the internal aspect of the pump. Lic promotes Na-activated K influx and Nac promotes Li-activated K influx. Cellular K inhibits Li-activated K influx, indicating that the interactions of Kc with the internal aspect of the pump is qualitatively different from the interaction with either Nac or Lic. The Hill coefficients for Na-promoted and Li-promoted K influx are similar and are both greater than unity, indicating the same number of multiple intracellular sites per pump for the two cations. The stoichiometry of coupling between efflux and K influx is also similar for Na and Li, and is close to 3 Na or 3 Li to 2 K. The Li-activated K influx appears to be independent of the residual Na which remains in cells prepared in Na-free solutions.
D000328:Adult; D001693:Biological Transport, Active / Q000187:drug effects; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008094:Lithium / Q000097:blood* / Q000494:pharmacology; D011188:Potassium / Q000097:blood* / Q000494:pharmacology; D012964:Sodium / Q000097:blood* / Q000494:pharmacology
D008094:Lithium; D012964:Sodium; D011188:Potassium