Description:
<jats:title>Abstract</jats:title><jats:p>The way in which the lectins concanavalin A (Con A) and <jats:italic>Ricinus communis</jats:italic> agglutinin (Ricin) alter the K<jats:sup>+</jats:sup> content of Ehrlich ascites tumor cells was investigated. Unidirectional and net fluxes were determined in unwashed cells during a time course following lectin addition. Total influx, ouabain sensitive influx, Mg<jats:sup>++</jats:sup>‐ and Na<jats:sup>+</jats:sup>‐K<jats:sup>+</jats:sup>‐ATPase activity were all unaffected. Cell ATP content was normal for at least 19 minutes after exposure to Con A. Early after contact with Ricin or Con A efflux was stimulated 2‐3‐fold, resulting in net K<jats:sup>+</jats:sup> loss, but after 20 minutes efflux had returned to normal. Ricin and Con A acted similarly although Ricin was present at only 1/50 the concentration of Con A. When the findings are evaluated together with previous work it is suggested that a particular membrane glycoprotein may be concerned in the efflux alteration observed.</jats:p>