[The influence of benzoctamine on dopamine and norepinephrine contents in substantia nigra and on the muscle stretch reflex of the cat (author's transl)].

The concentration of dopamine (DA) and norepinephrine (NE) are decreased to a maximum of 40% and 20%, respectively, in the substantia nigra of precollicular and prenigral decerebrated cats previously treated with benzoctamine (Tacitin) (0.7 mg/kg i.v.), while the tyrosine-hydroxylase and MAO activities remain unchanged. Muscle stretch reflexes recorded simultaneously showed a significant decrease of stretch tension which is evoked by a clear reduction of Ia discharges of the primary muscle spindle afferents. It would appear that benzoctamine suppresses reflexly evoked gamma-motoneurone discharges.