NEUROTOXIC EFFECT ON 2 FISH SPECIES AND A PC12 CELL-LINE OF THE SUPERNATE OF VIBRIO-ALGINOLYTICUS AND VIBRIO-ANGUILLARUM

The biological effects of supernates obtained from different strains o f Vibrio alginolyticus and Vibrio anguillarum isolated from diseased f ish have been studied by inoculation on two fish species, eel and rain bow trout, and two fish cell lines. These supernates possess neuroexci tatory properties, and so, when they are injected into both fish speci es, they trigger convulsions, wriggling, contortive swimming and respi ratory arrest coupled with increased respiratory reflex. Furthermore, after the application of the supernates on cultures of noradrenergic p heochromocytoma PC12 cells, an increase of acetylcholine, released fro m the cells was obtained. The amount of released acetylcholine depends on the source of assayed supernates and on the dose applied to the ce lls. On the basis of the results obtained with PC12 cells, we suggest that the supernates from pathogenic Vibrio strains injected into fish may elicit an increased release of acetylcholine in the motor endplate of some muscles related to locomotion and ventilation of the inoculat ed fish. (C) 1998 Elsevier Science B.V. All rights reserved.