Ultrastructural alterations produced in the liver of Gambusia affinis (baird and girard) after Dimecron toxicity and its subsequent effect on dehydrogenases

摘要

Liver ultra-structure studies are a sensitive indicator of the toxic action of xenobiotics. The E.M. photo micrographs provide unequivocal evidence of submicroscopic alterations in fish liver induced by Dimecron. This has cascading effect on variousenzyme activities. This paper deals with electron microscopic studies offish liver chronically treated with sub lethal doses of Dimecron, an organo phosphorus insecticide. Decrease in SDH activity suggests a reduction in the rate of oxidative metabolismat mitochondrial level possibly resulted by a change in ultra structure of the mitochondrion as observed in the study. LDH activity showed a sudden inhibition at the end of the first week and the inhibition that continued in activity was marginal. The reduced activity levels of dehydrogenase systems show impairment of oxidative metabolism. Hence it can be inferred that Dimecron toxicity results in low energy-state in tissues of the fish which necessitates these tissues to take advantage of their specialized physiological functions to derive energy under toxic stress.