Histofluorescence study and biochemical assay of catecholamines (Dopamine and Noradrenaline) during the course of arm-tip regeneration in the starfish,Asterina gibbosa (Echinodermata,Asteroidea)

Summary In the starfish, Asterina gibbosa, the histofluorescence method gives evidence of an aminergic activity in the course of arm-tip regeneration. This activity can be detected as variations in the localization and intensity of a green fluorescence in the nerve structures of the arm, the radial nerve, and the circumoral nerve ring connected to it. Biochemical assays reveal that dopamine levels increase on the 2^nd and 4^th days of regeneration, when the blastema is forming and when differentiation commences. The level of noradrenaline also increases on the 2^nd day after amputation of the arm.