The interaction of substrate and taurine modulates the outgrowth from regenerating goldfish retinal explants

Retinal growth from explants attached to different substrates was evaluated in the absence and the presence of various concentrations of taurine. Fiber thickness was higher in poly-L-lysine, collagen and laminin than in the other substrates tested. Explants on wheatgerm, soybean, and red kidney bean lectins did not show emission of neurites at 5 days in culture; growth on laminin was very poor at this period of time. By day 10 nerve growth index was possible to evaluate on soybean and laminin. Outgrowth from retinal explants on wheatgerm lectin was only observed in the presence of taurine. The percentage of growing explants on laminin was increased by the amino acid. Emission of neurites from explants on concanavalin A and lentil lectin was constant from 5 to 10 days in culture and was not accelerated or increased by taurine. Growth on poly-L-lysine and collagen was stimulated by the addition of taurine in a concentration-dependent manner. The amino acid stimulates outgrowth from explants attached to peanut lectin in a bell-shaped concentration dependency similar to that observed on poly-L-lysine. The effect of taurine on retinal explants is substrate-dependent, as an indication of the interaction of soluble molecular components plus charge and structure of the extracellular matrix in order to modulate the outgrowth from regenerating tissue.