Respiratory and cardiovascular effects of intraventricular cholecystokinin.
Cholecystokinin (1-300 ng) was administered into the lateral brain ventricle of chloralose-anesthetized cats while monitoring tracheal airflow, arterial blood pressure, and heart rate. Dose-related increases in respiratory activity occurred in each animal tested, and were due to an increase in tidal volume. When 300-1000 ng of cholecystokinin was administered intravenously, no respiratory stimulant effect was observed. These results indicate that cholecystokinin acts in the brain to stimulate respiration.