Abstract:

The effects of berbamine (Ber) on intracellular free Ca²⁺ ([Ca²⁺]i) in single cultured aortic VSMC were studied. Cultured VSMCs derived from rabbit aorta were loaded with fluorescent probe Fluo-3/AM and [Ca²⁺]i was measured by LSCM. In the presence of extracellular 2.0 mmol·L^-1 calcium ([Ca²⁺]0), Ber blocked [Ca²⁺]i increase caused by KCl 60 mmol·L^-1, ouabain 1 mmol·L^-1, norepinephrine (NE) 30 mmol·L^-1, serotonine (5-HT) 1 mmol·L^-1 and ATP 30 mmol·L^-1 respectively, and the time before fluorescent intensity (FI) reaches the peak value was also prolonged (P<0.05 or P<0.01). In the absence of extracellular Ca²⁺, Ber had no effect on the mobilization of [Ca²⁺]i induced by caffeine 40 mmol·L^-1. The results suggested that Ber was an effective agent for blocking Ca²⁺ influx caused by opening the VDCC and activating the ROCC but had no effect on intracellular Ca²⁺ release. Ber significantly inhibited the [Ca²⁺]i elevation caused by Ouabain.

Key words: Berbamine, Berbamine, Fluo-3/AM, Fluo-3/AM, Calcium, Calcium, Vascular smooth muscle cell, Vascular smooth muscle cell