Conjugates of Dopamine and Serotonin in Ventriculocisternal Perfusates of the Cat

Abstract: The in vivo formation of acid-hydrolyzable conjugates of dopamine and of serotonin (presumably dopamine- -O- -sulfate and serotonin- O -sulfate) in ventriculo- cisternal perfusions of the cat is described. Small amounts of these amine conjugates were detected under quiescent conditions and during evoked release of the parent amines. The amounts of conjugated dopamine in perfusate were increased during and immediately after the period in which release of dopamine was evoked, but were not affected by inhibition of monoamine oxidase. In contrast, the efflux of serotonin conjugate during the evoked release of serotonin was not increased unless monoamine oxidase was inhibited. The data suggest that conjugation of amines in the CNS may be of functional importance in their disposition either under conditions of augmented release or during inhibition of oxidative deamination.