EVALUATION OF EARTHWORM EXPOSURE TO CONTAMINATED SOIL BY CYTOMETRIC ASSAY OF CELOMOCYTES PHAGOCYTOSIS IN LUMBRICUS-TERRESTRIS (OLIGOCHAETA)

We measured non-specific immunity of the earthworm species Lumbricus t errestris by flow cytometric evaluation of coelomocytes phagocytosis a ctivity. In vivo and in vitro phagocytosis of fluorescent microspheres by coelomocytes were quantitated 18 h following intra coelomically in jections of microspheres or in vitro incubation of phagocytes with the microspheres. Then, cytometric evaluation of cell-associated fluoresc ence was performed using a FACScan (Becton Dickinson). Earthworms were washed, placed in extrusion medium containing 5% ethanol. Following t he contractions, the coelomocytes were collected. The cells were washe d and resuspended in appropriate medium. The flow cytometric acquisiti ons were performed immediately for in vivo phagocytosis or after 2, 18 , 24 and 48 h during in vitro kinetics. Preliminary results showed sig nificant in vivo and in vitro phagocytic activity of microspheres by c oelomocytes. Application of flow cytometry for validation of cellular and functional variables in earthworms appears to be a promising appro ach. Thus, our data showed that cytometric determination of phagocytic activity of coelomocytes with synthetic microspheres can be applied f or validation of non-specific immune response in the earthworm species , Lumbricus terrestris. (C) 1997 Elsevier Science Ltd.