Graphs showing the effects (mean ±s.e.m) of saline (10 μl, i.c.; n = 5) and SB-269970 (100 μg kg−1, i.c., n = 5) on changes in MAP, R-R interval, IRNA and IPNA evoked by chemoreflex stimulation with NaCN (75–150 μg kg−1, i.c.) in anaesthetized, neuromuscular-blocked and atenolol-pretreated rats. **P < 0.01 (compared to saline); †P < 0.05 (compared to control).