Abstract
Effects of La3+ and Gd3+ on Ca2+ influx were investigated in rat hepatoma H-35 cells by measuring the initial rate of45Ca2+ uptake. It was found that the maximum initial rate of Ca2+ uptake was increased six-to ten-fold at low concentrations of La3+ and Gd3+. Kinetic analyses by measuring the initial rate of Ca2+ influx at different external Ca2+ concentrations indicated the existence of two intracellular exchangeable components in the basal Ca2+ system, with low and high affinities for Ca2+, and only one class of Ca2+ binding sites was observed in the La3+-or Gd3+-treated cells. For high affinity, La3+ and Gd3+ increased both kinetic parametersK m andV max of basai Ca2+ influx. La3+ and Gd3+ compete directly with Ca2+ for Ca2+ binding site for low affinity. The kinetics is competitive.
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Li, X., Fong, W., Kwok, P. et al. Effects of La3+ and Gd3+ on Ca2+ influx in rat hepatoma H-35 cells. Chin.Sci.Bull. 44, 331–335 (1999). https://doi.org/10.1007/BF02885485
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DOI: https://doi.org/10.1007/BF02885485