Apomorphine-like effect of an aminotetralin on the linguomandibular reflex of the cat.

Low doses of 5,6-dihydroxy-2-dimethylaminotetralin (M-7) produced inhibition of the linguomandibular reflex in the cat. This inhibition was similar to that produced by apomorphine and was blocked by haloperidol, bulbocapnine or chlorpromazine. M-7 also had a brief but marked hypertensive effect. Gradual bradycardia also developed. These results indicate that M-7 inhibits the linguomandibular reflex by interaction at dopamine receptors, or 'apomorphine' receptors.