Biogenic monoamines in early embryos of sea urchins.

Indolylalkylamine determination was performed on the eggs and embryos of six species of sea urchins, using several fluorometric techniques, including the fluorescence of a substance itself and the fluorescence of its condensation products after treatment with orthophthaldialdehyde and ninhydrin. The serotonin-like substance of sea urchin embryos as well as of adults was shown to consist of at least two components, of which the major one is tryptamine or its derivative with a substituting group at aminonitrogen. Further, serotonin was found to be present at all developmental stages investigated. although at much lower concentrations. The results of this study suggest a regulatory role of 'prenervous' tryptamine in the early embryogenesis of the sea urchin.