CIRCADIAN DYNAMICS OF BIOCHEMICAL-ACTIVIT Y IN THE EPIPHYSIS OF SILVER-BLACK FOXES

Specific features of light-dependent biosynthesis of melatonin in the epiphysis are analyzed in female silver-black foxes. Just as in most p reviously studied animals, the serotonin and 5-hydroxyindolylacetic ac id content of epiphysis decreased during the dark time of the 24 h per iod, while the activity of the melatonin-synthesizing enzyme N-acetylt ransferase and melatonin content of epiphysis and plasma, on the contr ary, markedly and reliably increased. However, the pattern of changes in the neurotransmitters dopamine and noradrenaline shows specific fea tures.