Effects of berbamine on intracellular calcium concentration in cultured HeLa cells.
OBJECTIVE
To study the involvement of Ca2+ signaling and the effects of berbamine (Ber) on intracellular calcium concentration ([Ca2+]i) elevated in cultured HeLa cells.


METHODS
[Ca2+]i was measured by confocal microscopy in single HeLa cell loaded with Fluo 3-AM. The change of [Ca2+]i was represented by fluorescent intensity (FI).


RESULTS
(1) In the presence of extracellular Ca2+ 1.3 mmol.L-1, the resting level of FI was 186 +/- 44, n = 49 cells from all control experiments, and KCl, NE, caffeine, and calcimycin (Cal) all induced [Ca2+]i elevations in cultured HeLa cells. (2) The resting level of FI was not affected by pretreatment with Ber. The FI increased by KCl 60 mmol.L-1, NE 100 micromol.L-1, and Cal 30 micromol.L-1 were attenuated (P < 0.05 or P < 0.01), the slope and the time to peak of FI increase were decreased and prolonged. (3) In the absence of extracellular Ca2+, caffeine 80 mmol.L-1-induced [Ca2+]i mobilization was not inhibited by Ber 100 micromol.L-1 pretreatment. (4) These effects of Ber were similar to those of verapamil (Ver) 10 mumol.L-1.


CONCLUSIONS
Although it was derived from cervical cancer, the HeLa cells which were belong to the nonexcitable cell possessed the similar biological properties with excitable cells, and Ca2+ also played a crucial role in signal transduction processes.
Department of Pharmacology, Harbin Medical University, Harbin 150086, China. liby@ems.hrbmu.edu.cn
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D000470:Alkaloids / Q000494:pharmacology*; D044182:Benzylisoquinolines; D001693:Biological Transport, Active; D002110:Caffeine / Q000037:antagonists & inhibitors; D000001:Calcimycin / Q000037:antagonists & inhibitors; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D009638:Norepinephrine / Q000037:antagonists & inhibitors; D011188:Potassium / Q000037:antagonists & inhibitors; D015398:Signal Transduction
D000470:Alkaloids; D044182:Benzylisoquinolines; D002121:Calcium Channel Blockers; D000001:Calcimycin; D002110:Caffeine; D011188:Potassium; D002118:Calcium; C027870:berbamine; D009638:Norepinephrine