>melatonin  n  [Gk melas black + -tonin (as in serotonin)] (1958) :
>a vertebrate hormone of the pineal gland that produces lightening
>of the skin by causing concentration of melanin in
>pigment-containing cells

Io non pote trovar isto o serotonin in mi varie dictionarios altere que
le anglese.

Io necessita dictionarios medic in iste altere linguas.

Stan Mulaik