Fig. 2. GPR55 activation in RBMVEC increases cytosolic Ca²⁺ concentration, [Ca²⁺]_i.

A, Example of increases in F340/F380 fluorescence ratio in RBMVEC produced by LPI (10 μM), the GPR55 agonist; the response was prevented by ML-193 (10 μM), a GPR55 antagonist. B, LPI (10 μM) produced a fast and transitory increase in cytosolic Ca²⁺ concentration, [Ca²⁺]_i (solid trace), ML-193 abolished the response to LPI (dashed trace). C, Comparison of the average amplitude ± SEM of the increase in [Ca²⁺]_i produced by different concentrations of LPI, and LPI in cells pretreated with ML-193. LPI (0.1, 1 and 10 μM) produced a dose-dependent increase in [Ca²⁺]_i (*P < 0.05).