In vitro generation of reactive oxygen species by free coelomic cells of the annelid Eisenia fetida andrei: an analysis by chemiluminescence and nitro blue tetrazolium reduction.

ABSTRACT

Coelomocytes of the earthworm Eisenia fetida andrei were activated in vitro with various stimulants in order to investigate their capacity to produce reactive oxygen species. Analysis by luminol-enhanced chemiluminescence and nitro blue tetrazolium reduction suggests the production in vitro of reactive oxygen species by both categories of free coelomocytes, leucocytes and chloragocytes, while affecting different modalities a respiratory burst-like reaction is exhibited by leucocytes in the presence of zymosan but not bacteria; a moderate production of reactive oxygen species spontaneously occurs when chloragocytes aggregate together. A substantial reduction of reactive oxygen species production, rapidly occurring after addition of exogenous superoxide dismutase, was interpreted as indicating a prominent role of the superoxide anion, O2.-. The factors modulating the coelomocyte generation of reactive oxygen species, as well as the presence of lipofuscin in brown bodies, support the opinion that production of reactive oxygen species may be an immune defense process occurring under in vivo conditions.