Figure 6. Responses of cardiac afferents to ischaemia before and after blockade of ET_A with receptors with BQ-123.

A, bar graph summarizing changes in activity of seven cardiac sympathetic afferents before (open bar) and during (filled bar) 5 min of myocardial ischaemia. B, responses of another eight cardiac sympathetic afferents to myocardial ischaemia before and after treatment with BQ-123. C, neurohistograms of summated 2 s discharge activity from all eight afferents during ischaemia before (a) and after (b) treatment with BQ-123. *P < 0.05 compared with control. †P < 0.05 post-BQ-123 vs. pre-BQ-123.