Nuclear localization of melatonin in different mammalian tissues: Immunocytochemical and radioimmunoassay evidence

Melatonin was detected by an improved immunocytochemical technique in the cell nuclei of most tissues studied including several brain areas, pineal gland, Harderian gland, gut, liver, kidney, and spleen from rodents and primates. Cryostat sections from tissues fixed in Bouin's fluid, formalin, or acetone/ethanol were used. The nuclear staining appeared primarily associated with the chromatin. The nucleoli did not exhibit a positive reaction. The...