Figure 1.

Agonist-dependent calcium mobilization in 300-19 cells expressing G_αi- and G_αq-coupled receptors. Stably transfected 300-19 cells were incubated with or without 100 ng/ml of PTX for 24 h and loaded with Indo-1 AM. Intracellular calcium levels were measured as described. Shown are calcium fluxes in response to 100 nM of MCP-1 (CCR2B), 100 nM of U50488 (κ-opioid receptor), 200 μM of carbachol (m3 receptor), and 10 nM of thrombin (PAR-1 thrombin receptor) from a representative experiment (n = 3). The agonists used did not induce calcium fluxes in the absence of the appropriate cognate receptors.