TABLE 1

Relative contribution of clearance systems to Ca2+ removal*

[Ca2+]i0.5 μmol/l0.9 μmol/l1.5 μmol/l*1.9 μmol/l
SERCA pumps6861
PMCA pumps16123035
NCX13166362
Total accounted for97899397
  • Data are %.

  • *

    * The rate of [Ca2+]i decay, d[Ca2+]i/dt, was determined at four [Ca2+]i levels from averaged records. Table shows the percentage of the rate that was inhibited by appropriate blocking conditions.

  • Values from TG-pretreated cells, which represent the percentage contribution of the PMCA and NCX to the clearance (by the Na8.8 and Li7.4 methods) when SERCA pumps are disabled.