Influence of toxic chemicals on the chemotactic response of fish macrophages

The chemotactic efficiency of macrophages isolated from the kidney of spot, Leiostomus xanthurus , and hogchoker, Trinectes maculatus. was determined in fish captured from the York River and the heavily polluted Elizabeth River (Virginia). Chemotactic activity was quantified in Boyden chambers using Escherichia coli as the chemotactic stimulus. Macrophage chemc-taxis was found to be markedly reduced in the Elizabeth River fish as compared to York River controls. Chemotactic migrations of macrophages at 90 min were 55% and 33% for control and experimental spot, respectively. Values for control and experimental hogchoker were 85% and 56%, respectively. The macrophage chemotactic activity of Elizabeth River fish returned to normal (spot, 56%; hogchoker, 80%) after the fish were held in clean water for 3 weeks. This indicates that the decreased chemotactic activity was related to exposure to Elizabeth River pollutants but may be reversible.