The effect of Lanthanum on electrophoretic mobility and passive cation movements of the ehrlich ascites tumor cell

✍ Scribed by Thomas C. Smith

• Publisher: John Wiley and Sons
• Year: 1976
• Tongue: English
• Weight: 426 KB
• Volume: 87
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040870107

✦ Synopsis

Abstract

We have investigated the effects of La^+3^ binding to the surface of Ehrlich ascites tumor cells on cell electrophoretic mobility and passive movements of Na^+^ and K^+^. Incubation of tumor cells in La^+3^‐containing media results in a La^+3^ concentration‐dependent decrease in net surface charge negativity. At [La^+3^] greater than 0.5 mM, the net surface charge becomes positive with maximum positivity occurring at [La^+3^] = 0.9 mM. The effects of La^+3^ binding on passive Na^+^ and K^+^ movements were investigated by following ^22^Na and K^+^ losses from ouabain‐inhibited cells. Neither low (0.02) nor high (1.0 mM) [La^+3^] had any effect on the K^+^ efflux rate coefficient. ^22^Na losses from control and La^+3^‐treated cells were consistent with washouts from two cellular compartments. Low [La^+3^] (0.02 mM) was without effect on Na^+^ loss from the cells. However, higher [La^+3^] (1.0 mM) resulted in a 48% inhibition of Na^+^ loss from the more slowly exchanging compartment. These results are not consistent with simple electrostatic interactions exerting a major influence on the passive movements of Na^+^ and K^+^. It is suggested that La^+3^ interacts with sites specific for Na^+^, perhaps involved in a carrier‐mediated exchange system.