The response of few-fiber carotid chemoreceptor preparations to almitrine in the dog

Abstract

Almitrine, a long-lasting peripheral chemoreceptor stimulant, was given to nine dogs via intracarotid injection. Carotid chemoreceptor activity was recorded from single or few-fiber afferent nerve preparations. Doses of 10–20 μg/kg were generally sufficient to produce a brisk stimulatory response of less than 30 min duration. In four dogs decreasing arterial [Formula: see text] was found to allow a greater than additive response to almitrine. Infusions of NaHCO3 appeared to depress the response to almitrine whereas changing arterial [Formula: see text] had little effect on the carotid chemoreceptor response to almitrine. Neither dopamine infusion nor dopamine receptor blockade altered the responsiveness of the carotid chemoreceptors to almitrine.