Melatonin levels in developing Xenopus laevis

Abstract

1. 1. Spectrophotofluormetric determinations of melatonin levels in embryonic stages of the amphibian Xenopus laevis have been made. 2. 2. Significant changes occur at the times of first embryonic movement, hatching and active larval swimming. 3. 3. There is some indication that a fivefold increase in melatonin, occurring at the time of active larval swimming, is the result of enzyme activity in the retina of the eye. 4. 4. The suggestion is made that melatonin metabolism is related to photomechanical changes in retinal cells.