[The characteristics of melatonin biosynthesis in the epiphysis of relatively wild and domesticated silver foxes Vulpes fulvus].

In earlier experiments, it had been demonstrated that at night melatonin concentration in the pineals of foxes Vulpes fulvus which were subjected to a prolonged selection for domestic behaviour, was higher than in undomesticated ones. A more detailed study of melatonin biosynthesis showed that concentration of melatonin precursor, namely serotonin, as well as the activity of N-acetyltransferase and hydroxyindole-O-methyltransferase participating in melatonin synthesis, together with the content of dopamine and noradrenaline which regulate this process, are practically identical in the pineal gland of both groups of animals. Possible causes of differences in melatonin concentration in the pineal tissue of domesticated and undomesticated foxes are discussed.