ABSTRACT
Various substances have been used to investigate physiological and physiophatological processes in animals. In this study, we investigated the effects of acetylsalicylic acid (ASA, aspirin) on the regeneration of actinotrichia, skeletal structures of the caudal fin of teleosts. Two groups of fish (Tilapia rendalli) were maintained in aquaria with dechlorinated water at 24 graus Celsius, with one group being exposed to ASA (0.1 g/l) for 24 h. Thereafter ASA-treated and untreated (control) fishes were anesthetized and their tail fin amputated. After periods ranging from 4-12 days, the fishes were sacrified and the regeneration tissue was processed for light and transmission electron microscopy and picrosirius-hematoxylin staining. Control specimens ahowed normal regeneration of the actinotrichia, whereas all (except one) of the ASA-treated fishes showed no regeneration. The 20 ASA-treated fishes devoid of actinotrichia had varying degrees pf caudal fin regeneration. These results indicate that, as in mammal, aspirin also affects biological processes in fish. Based on reports in the literature, we hypothesize that ASA interfered with the transcripition of the fibroblast genes necessary for the synthesis of elasoidin, or altered the typical rapid turn-over of this protein, thereby affecting regeneration could be a valuable approach for instigating cell-matrix interactions. This model could also be useful for evaluating the toxic effects of river pollution and chemical damping.