Resurgence of interest in the mammalian pineal organ and recemit successful experimental linkimig of its activity with the sympathetic system and environmental lighting, have been brought about in part by the pineal's content and metabolism of 5-hydroxy- and 5-methoxyindoles. Methods are being applied for exacting precise informatiomi concerning localization and quantification of these compounds and their derivatives within pineal tissue. Much remains to be learned, however, concerning the identity of postulated and unknown, metabolically active pineal indoles and their derivatives. Predilection, perhaps premature, for the hormonal possibilities of these derivatives has led to a neglect of the possibilities of strictly intramural or intrapineal functions for these compounds. The latter seem most promising in the light of recent uhtrastructural, histochemical, biochemical and comparative studies. The likelihood of a basic, primitive similarity between pineal, brain amid retinal tissue in their metabolites and metabolism of 5-hydroxyindoles also deserves study.
- 1965 by The Williams & Wilkins Co.