Determination of the macrophage chemiluminescent response in Fundulus heteroclitus as a function of pollution stress

Abstract

The Southern Branch of the Elizabeth River in Virginia is highly contaminated primarily with polynuclear aromatic hydrocarbons (PAH) in the sediments. Possible correlations between environmental stress on a fish population and an altered immune response were examined using the chemiluminescent (CL) assay on macrophages isolated from Fundulus heteroclitus. Testing the CL response in Elizabeth River (ER) and York River (YR) populations demonstrated that CL activity was significantly higher in the ER fish. CL counts per minute per cell (cpm/cell) for ER fish ranged from 0·82-7·98 and 0·27-3·20 for YR fish. Mean peak macrophage CL activity for the ER population was 3·72 while that for the YR population was 1·20. The field results suggest that macrophages may be stimulated from constant exposure to a stressful environment or that certain chemicals may have stimulatory effects on CL activity. After 3 weeks of acclimation in ER water, YR fish exhibited the same CL activity found in ER populations. ER fish held in YR water for 3 weeks exhibited CL activity similar to the YR population. Mean peak CL activity for ER fish held in YR water was 1·20, while mean peak activity for YR fish held in ER water was 5·28. Results demonstrate that statistically significant differences in macrophage CL activity between the ER and YR Fundulus exist and that a reversal in CL activity occurs if fish are exposed to alternate environmental conditions.