The effect of potassium on carotid chemoreceptor activity and ventilation in the cat

Intravenous injections of potassium chloride were given to anaesthetised cats to produce rises in arterial plasma potassium within the range of those occurring in man during exercise. Carotid chemoreceptor activity was recorded as action potentials from a single or few fibre preparation of the right sinus nerve. Arterial potassium was recorded continuously using a potassium electrode placed in the abdominal aorta. In response to the potassium injections there was an increase in carotid chemoreceptor activity, which closely followed the arterial potassium concentration, and an increase in ventilation. It is suggested that potassium released from muscle may be an important drive to ventilation in exercise.