Fig. 4: Carotid body P2X3-receptors mediate afferent hypersensitivity and chemoreflex hyperreflexia in heart failure (HF) rats.

a Integrated (∫) recordings of carotid sinus nerve (CSN) activity during activation of peripheral chemoreceptors (potassium cyanide - KCN; 0.05 ml, i.v., 0.05%) in anaesthetized rats. Note presence of elevated tonicity (relative to sham and dotted line) and augmented evoked response in CSN b in the chronic HF (CHF) rats and that these were both normalized after P2X3 receptor blockade (a, b; drug was given systemically). Data are shown as mean ± SD and were tested for normality (Kolmogorov–Smirnov test) and compared using One-way ANOVA Bonferroni post-test. n = 7 per group; ***P < 0.001. The chemoreflex hyperreflexia of both the thoracic sympathetic (tSN) (c, d), and abdominal nerve (AbN) activity (c. e), was normalized by P2X3 receptor blockade in the carotid bodies performed by microperfusion of antagonist in the in situ preparation. ∫PN integrated phrenic nerve activity. Data are shown as mean ± SD; n = 10 and 16 for sham and HF group, respectively. One-way ANOVA Bonferroni post-test. **P < 0.01, ***P < 0.001. Source data are provided as a Source Data file.