Hypertension is critically dependent on the carotid body input in the spontaneously hypertensive rat

Key points  Peripheral chemoreflex sensitivity is enhanced in hypertension yet the role of these receptors in the development and maintenance of high blood pressure remains unknown.  Carotid chemoreceptors were denervated in both young and adult spontaneously hypertensive rats (SHRs) by sectioning the carotid sinus nerves bilaterally while recording arterial blood pressure chronically using radio telemetry.  Carotid sinus denervation (CSD) in the young animals prevented arterial pressure from reaching the hypertensive levels observed in sham-operated animals whereas in adult SHRs arterial pressure fell by ∼20 mmHg.  After CSD there was a decrease in sympathetic activity, measured indirectly using power spectral analysis and hexamethonium, and an improvement in baroreceptor reflex gain.  Carotid bodies are active in the SHR and contribute to both the development and maintenance of hypertension; whether carotid body ablation is a useful anti-hypertensive intervention in drug-resistant hypertensive patients remains to be resolved.