Cytological alterations in the liver of rainbow trout Oncorhynchus mykiss after prolonged exposure to low concentrations of waterborne endosulfan

Abstract

ABSTRACT-In order to elucidate sublethal cytopathological alterations in hepatocytes, mature male rainbow trout Oncorhynchus mykiss were exposed to 1, 10. 50, and 100 ng I-' technical grade endosulfan (ThiodanTM, 70% a-and 30 % P-isomers) for 28 d. Whereas stereological parameters, i.e. relative volumes and numbers of cell organelles, were unaffected, qualitative ultrastructural alterations were detectable from 10 ng I-' endosulfan. The No-Observed-Effect Concentration (NOEC) for cytological alterations was determined to be 1 ng I-' endosulfan, i e 3 orders of magnitude below the LC,, value Cytological effects that were probably of an adaptive nature included proliferation of SER and circular arrays of RER indicating induction of mixed-function oxygenases (MFO) as well as an increase in lysosomal elements at 50 and 100 ng I-' endosulfan, probably due to enhanced cellular turnover In addition, at 250 ng 1-' endosulfan, degenerative effects such as dilation of intermembranous spaces in mitochondria, deformation of mitochondria, myelin formation in peroxisomes and cytoplasm, and vesiculation and dilation of RER cisternae were observed. Although there was no indication of specific sublethal modes of toxic action except for MFO induction, the present study indicates that endosulfan has toxic impacts at concentrations of environmental relevance.

Exposure to Thiodan&REG results in lipofuscin accumulation in hepatocytes of the freshwater catfish Tandanus tandanus

“…This suggests that these changes are not species-specific. The other studies investigated changes only in males (Arnold et al 1995(Arnold et al , 1996. Our results were very similar for males and females (after 28 d ER changes were observed in 39.5% of hepatocytes in treated females and 46.3% in treated males).…”

“…Vesiculation and dilation of RER and proliferation of SER were present in hepatocytes of male rainbow trout Oncorhynchus mykiss after exposure to 0.01, 0.05 or 0.1 µg l -1 endosulfan for 28 d (Arnold et al 1996). Proliferation of both RER and SER in liver cells were apparent after exposure of male rainbow trout O. mykiss to 0.05 µg l -1 endosulfan and 1 to 10 µg l -1 organophosphate disulfoton for 18 or 34 d (Arnold et al 1995).…”

“…Resale or republication not permitted without written consent of the publisher erately hazardous (Arnold et al 1996). Technical-grade endosulfan consists of a mixture of 2 isomers-alpha and beta endosulfan.…”

Heterogeneous Photocatalytic Degradation of Disulfoton in Aqueous TiO2 Suspensions: Parameter and Reaction Pathway Investigations

“…1,2 The primary acute toxic effect caused by organophosphorus pesticides is usually the inhibition of enzyme acetylcholinesterase, which plays a critical role in the proper functioning of nerve cells. 3,4 OPs act as the cholinesterase inhibitors in insects and mammals and bring about a non-reversible phosphorylation of esterases in the organisms' central nervous system. This activity is also responsible for the toxicity in humans.…”

Changes in the olfactory mucosa of the black bullhead Ictalurus melas induced by exposure to sublethal concentrations of sodium dodecylbenzene sulphonate

“…Most morphological studies on pathology induced by major environmental toxicants (organochlorine and polyaromatic hydrocarbons) in teleosts has been carried out on the liver (Klaunig et al 1979, Hawkins et al 1990, Braunbeck et al 1992, Arnold et al 1996, Hinton & Couch 1998, a crucial organ in metabolism, and the main site of activity of cytochrome P4501A1 isoform (CYP1A1: Braunbeck & Volkl 1991, Lester et al 1993, Goksoyr & Husoy 1998, Sarasquete & Segner 2000. Various water-borne xenobiotics induce ex novo synthesis of the enzymatic system in fishes, while in teleost CYP1A1 has been immunolocalized also in extrahepatic systems, including the olfactory organs (Smolowitz et al 1992, Monod et al 1995.…”