Figure 2. Physiological responses to activation of the peripheral chemoreflex with cyanide.

Injection of cyanide (200 μg kg⁻¹, i.v.) increased splanchnic sympathetic nerve activity (SNA, A), heart rate (HR, B), and mean arterial pressure (MAP, C) in all rats. In rats exposed to CIH (n = 7), the rise in SNA and HR was exaggerated compared to control rats (n = 8). *Significantly different from control rats, P < 0.05, unpaired t test.