LOCUS OF EMETIC ACTION OF EPINEPHRINE AND DOPA IN DOGS’

Excessive doses of epinephrine have been shown to produce vomiting in animals (Sollmann, 1957). Hatcher and Weiss (1923) reported that epinephrine applied on the floor of the fourth ventricle induced emesis in dogs. Feldberg and Sherwood (1954) observed that rather large doses of epinephrine injected into the lateral ventricle of unanesthetized cats caused vomiting. Borison (1959) confirmed the results of these last investigators and also reported that the vomiting response they had noted was abolished by ablation of the trigger zone. Dihydroxyphenylalanine (dopa), the precursor of endogenous epinephrine, is also found in plants. The bean of Mncuna capitata SW, grown i