VENTILATORY RESPONSE TO CHOLECYSTOKININ TETRAPEPTIDE IN ANESTHETIZED DOGS

CHOLECYSTOKININ (CCK) has been implicated in the genesis of panic diso rder. In this study we measured the ventilatory response to i.v. injec tion of CCK-tetrapeptide (CCK-4) in anaesthetized dogs. We found an im mediate and transient increase in minute ventilation. The response was large (more than 100% of baseline) and lasted 1-2 min. Repeated CCK-4 injection produced a somewhat reduced response, suggestive of a sligh t degree of tachyphylaxis. Blood pressure and heart rate changed only slightly (<10%), while respiratory mechanical parameters remained unch anged following CCK-4 administration. We conclude that CCK-4 has a sig nificant effect on ventilation in the anaesthetized dog, which suggest s that this species may provide a useful quantitative assay for the an xiogenic effects of CCK.