Figure 5. Pharmacological analysis of the signalling mechanisms responsible for PE-induced stimulation of NO_i release.

Each experiment was performed by testing PE in the absence (control) and presence (test) of each drug on myocytes isolated from the same hearts. The control values from each experiment (n = 23) are grouped together for clarity. Compared with control (open bar) prazocin (1 μm), l-NIO (10 μm), W-7 (10 μm) and LY294002 (10 μm) each significantly inhibited PE-induced stimulation of NO_i release. H-89 (2 μm) blocked approximately 50% of PE-induced NO_i production. Incubation of cells in PTX had no effect on PE-induced NO_i production. The numbers in parentheses indicate the number of cells tested in each experiment. *P < 0.05.