Effects of berbamine on intracellular calcium concentration in cultured HeLa cells

To study the involvement of Ca2+ signaling and the effects of berbamine (Be r) on intracellular calcium concentration ([Ca2+ ](i)) elevated in cultured HeLa cells. METHODS: [Ca2+ ](i) was measured by confocal microscopy in sin gle HeLa cell loaded with Flue 3-AM. The change of [Ca2+ ](i) was represent ed by fluorescent intensity (FI). RESULTS: (1) In the presence of extracell ular Ca2+ 1.3 mmol.L-1, the resting level of FI was 186 +/- 44, n = 49 cell s from all control experiments, and KCl, NE, caffeine, and calcimycin (Cal) all induced [Ca2+](i) elevations in cultured HeLa cells. (2) The resting l evel of FI was not affected by pretreatment with Ber. The FI increased by K Cl 60 mmol.L-1, NE 100 mu mol.L-1 and Cal 30 mu mol.L-1 were attenuated (P < 0.05 or P < 0.01), the slope and the time to peak of FI increase were dec reased and prolonged. (3) In the absence of extracellular Ca2+, caffeine 80 mmol.L-1-induced [Ca2+ ](i) mobilization was not inhibited by Ber 100 mu m ol.L-1 pretreatment. (4) These effects of Ber were similar to those of vera pamil (Ver) 10 mu mol.L-1. CONCLUSION: Although it was derived from cervica l cancer, the HeLa cells which were belong to the nonexcitable cell possess ed the similar biological properties with excitable cells, and Ca2+ also pl ayed a crucial role in signal transduction processes.