The CCKA receptor antagonist devazepide inhibits the effect of apomorphine on vasopressin release in pigs.

1. A transient increase in plasma vasopressin concentrations represents a physiological correlate of nausea in animals that vomit. 2. The CCKA receptor antagonist devazepide has previously been shown to inhibit vasopressin release induced in pigs by intravenous (i.v.) CCK. 3. This study investigated whether devazepide (70 micrograms/kg i.v.) would affect vasopressin secretion induced in pigs (n = 6) by the emetic drug apomorphine (25 micrograms/kg i.v.). 4. Apomorphine stimulated vasopressin release in the 30 min period following injection; this effect was prevented by prior administration of devazepide. 5. The results suggest that CCKA receptor antagonists may have the ability to prevent nausea and/or emesis.