[Accumulation of exogenous monoamines in the notochord of lampreys: fluorescence microscopy and radiography study].

Storage of biogenic amines was studied in the notochord of the lamprey (Lampetra planeri) after injection of cold or tritiated amines or their precursors. After injection of dopamine, noradrenaline or 5-hydroxytryptophane, an intense formaldehyde-induced fluorescence was observed in the cytosol of chordal cells and in the perichordal sheat. A similar location occurred after injection of the same tritiated products. No qualitative or significant quantitative differences could be distinguished between the larval and the metamorphosing forms. RO4-4602, a decarboxylase inhibitor, and Nialamide, a monoamine-oxydase inhibitor, did not modify significantly the incorporation of 3H-5-hydroxytryptophan. Using histochemical technique a monoamine oxydase activity could be detected in the nervous system and in the muscle but was not shown in the notochord.