Hepatic disorders induced by a sublethal concentration of procymidone (fongicide dicarboximide) in Brachydanio rerio (Teleostei, Cyprinidae): Histo-cytological approach.

Procymidone [N-(3,5 dichlorophenyl)-1,2 dimethylcyclopropane-1,2 dicarboxim ide] is a fungicide frequently used against Botrytis, Sclerotinia and other s. It persists several weeks in soils and thus may pollute aquatic environm ents and organisms. Non-specific liver histo-cytological disorders in Brach ydanio rerio exposed to a sublethal concentration of 1 mg.l(-1) of the fung icide occurred after 4, 7 and 14 days of exposure. They were time-dependent . Adaptative (glycogen depletion, lipid accumulation, disappearance of the perisinusoidal microvillies) and degenerative events (disorganization of he patic cords, perivascular lysis of the parenchyma) associated with an incre ase of the non-specific cellular immune response (increased number of macro phages) occurred. Additionally, unusual perturbations were observed : devel opment of concentric hepatocyte arrangements and of cytoplasmic protrusions between adjacent hepatocytes. Hepatic recovery was obvious after 14 days o f depuration (reduction of the lytic features and metabolic activation of h epatocytes). The results give evidence of microscopic disorders in B. rerio liver induce d by procymidone. The analysis of liver responses in experimentally exposed fish can provide a basis for recognizing toxicity syndromes and may theref ore be used as biomarker in the prognosis of the effects of aquatic polluta nts.