FIGURE 5.
Store-operated currents (ISOC) in normal (NCM460) and colon carcinoma (HT29) cells. A, current-voltage (I-V) relationship of ISOC in normal cells. Average I-V relationships of ISOC obtained from NCM460 cells (n = 18). In this set of experiments SOCs were activated by passive Ca2+ store depletion with intracellular EGTA (20 mm). In this and following electrophysiological data, the current amplitudes were normalized with respect to cell capacitance; inward and outward currents were measured at −80 and +80 mV, respectively, and average plots are presented as mean ± S.E. B, averaged time course recordings of ISOC obtained from NCM460 cells (n = 18). C, I-V relationship of ICRAC-like currents in colon carcinoma cells. Average I-V relationships of ISOC obtained from the 36% of HT29 cells examined (n = 11). D, averaged time course recordings of ISOC obtained from HT29 cells (n = 31). E, I-V relationship of the nonselective ISOC in colon carcinoma cells. Average I-V relationships of ISOC obtained from the 64% of HT29 cells tested (n = 20). F, maximal current amplitude of ISOC in normal and tumor cells (n = 18–31, *, p < 0.05).