The article studies the effect of a newly-synthesized aminotetraline derivative with code 1b on some presynaptic mechanisms of nerve transmission. Compound 1b (1 X 10(-9) M) increases the contractions of electrically stimulated isolated rat anococcygeal muscle: on the background of cocaine (1 X 10(-7) M), the contractile response after 1b is potentiated, whereas after phentolamine (1 X 10(-9) M) compound 1b does not increase the contraction of the muscle. Compound 1b in concentration from 1 X 10(-8) M to 1 X 10(-7) M manifests a concentration-dependent potentiating effect (EC50-3.95 X 10(-8) M) on the contractile response of electrically stimulated isolated rat vas deferens. The alpha-adrenergic blocker yohimbin (1 X 10(-7) M) and compound 1b (1 X 10(-6) M) increase the contractions of electrically stimulated mouse vas deferens. The potentiating effect of 1b is eliminated by clonodone (1 X 10(-19) M) and haloperidol (1 X 10(-5) M). On electrically stimulated guinea-pig ileum 1b (2 X 10(-6) M) and morphine (1 X 10(-6) M) inhibit the contractions of the isolated organ, while their combined administration potentiates the inhibitory effect of morphine. Both the combined and the independent effects of 1b and morphine are eliminated by naloxone (1 X 10(-6) M) and 4-aminopyridine (1 X 10(-7) M). Both compound 1b (2 X 10(-6) M) and morphine (1 X 10(-6) M) manifest potentiated inhibitory effect on the contractile response of guinea-pig ileum, administered on the background of dopamine (1 X 10(-5) M) and haloperidol (1 X 10(-6) M).(ABSTRACT TRUNCATED AT 250 WORDS)