Species-specific reaction of liver ultrastructure in zebrafish (Brachydanio rerio) and trout (Salmo gairdneri) after prolonged exposure to 4-chloroaniline

Abstract

The morphological alterations of hepatocytes of female zebrafish, Brachydanio rerio, and fingerling rainbow trout, Salmo gairdneri, following prolonged exposure to 0.04, 0.2 and 1 mg/L of 4-chloroaniline were investigated by means of light and electron microscopy. Changes in peroxisomes were visualized by cytochemical demonstration of catalase activity after incubation in the alkaline diaminobenzidine medium. The amount of storage products was illustrated by the silver impregnation technique. In a dose-dependent manner, the reaction of female zebrafish liver is characterized by a disturbance of hepatocytic compartmentation, progressive fenestration and fractionation of the rough endoplasmic reticulum (RER), a decrease in the number of peroxisomes and catalase activity, stratified inclusions in mitochondria, and an augmentation of lysosomes and myelinated bodies. Trout hepatocytes display nuclear inclusions, fractionation and vesiculation of the RER, and an increase in mitochondria, but a decrease of peroxisomes and catalase activity. Whereas glycogen stores are exhausted at 1 mg/L 4-chloroaniline, lipid deposits are amplified. An elevated rate of hepatocytic mitosis as well as the occurrence of glycogen-condensing cells probably derived from hepatocytes indicate the induction of proliferative processes in trout liver. Evaluation and comparison of results with earlier reports suggest that despite the unspecificity of some alterations the combination of pathological symptoms yields a syndrome specific of the species and the substance studied. As a consequence, histological and cytological investigations are recommended as a routine supplement in an integrated test schedule for the assessment of sublethal effects of pollutants in the aquatic environment.

Histopathological changes in liver and gill epithelium of Nile tilapia, Oreochromis niloticus, exposed to waterborne copper

“…Alterations in the size of nucleus have been previously regarded by Paris-Palacios et al (2000) in Brachydanio rerio exposed to sublethal concentrations of copper sulphate. Braunbeck et al (1990) referred that alterations in size and shape of nucleus have often been regarding as signs of increased metabolic activity but may be of pathological origin.…”

Cytological and Biochemical Alterations in Carassius auratus Hepatocytes from Exposure to Sediment Containing Dioxins and Related Compounds

“…It has been reported that the proliferation of SER is regarded as a general sign of intoxication and is associated with induction of the detoxification process in mammals (Phillips et al 1987) and fish (Hinton et al 1978;Braunbeck et al 1989). Other studies of fish exposed to organic environmental contaminants found proliferation of SER (Braunbeck et al 1990). Because many enzymes, such as cytochrome P450 (measured as EROD activity), are embedded in SER and these enzymes are involved in detoxification of many organic toxicants (Van der Weiden et al 1989), SER proliferation also is a sensitive indicator of exposure to organic toxicants in fish.…”

“…Because many enzymes, such as cytochrome P450 (measured as EROD activity), are embedded in SER and these enzymes are involved in detoxification of many organic toxicants (Van der Weiden et al 1989), SER proliferation also is a sensitive indicator of exposure to organic toxicants in fish. Some reports have described the reduction of RER and an increase of heterogenicity (Phillips et al 1987;Braunbeck et al 1990;Braunbeck 1992) and vesiculation after PCB or PAH exposure in fish. In our observations, the dilation, fragmentation, and vesiculation of RER is very similar to the result reported by Norrgren et al (1993) and Engwall et al (1994).…”

Perturbations hépatiques induites expérimentalement par une concentration sublétale de procymidone (fongicide dicarboximide) chez Brachydanio rerio (Téléostéen, Cyprinidé) : approche histo-cytopathologique

“…L'augmentation du nombre des macrophages au cours de l'intoxication correspond à une activation d'une réponse immunitaire cellulaire non spécifique qui peut être corrélée à l'accroissement de la destruction du tissu hépatique, tel que cela a été montré par STANTON (1965) et BRAUNBECK et al (1989, 1990b.…”