Effects of herbicide on the kidneys of two Venezuelan cultured fish: Caquetaia kraussii and Colossoma macropomum (Pisces:Ciclidae and Characeae)

The use of chemical pesticides and herbicides has increased environmental pollution and affected ichthyofauna in the watersheds where they are used.We studied the effect of an herbicide, triazine, on the kidneys of two species (Caquetaia kraussii and Colossoma macropomum )widely found in Caribbean and South American rivers.In Venezuela,these species are abundant and have a high aquaculture potential because they may be cultured and reproduced in captivity.Four kidney samples from juveniles of each species exposed to the herbicide were examined by Transmission Electron Microscopy.Kidney tubule alterations included loss of plasmalemma and cell interdigitations, misshaped mitochondria,decrease in rough endoplasmic reticulum and free polysomes,and the presence of autophagic vacuoles and primary lysosomes.These alterations at the cellular level may explain fish behaviour in terms of kidney tubule pathology,and relative amounts and conditions of organelles within affected cells

Effects of herbicide on the kidneys of two Venezuelan cultured fish: Caquetaia kraussii and Colossoma macropomum (Pisces: Ciclidae and Characeae).

The use of chemical pesticides and herbicides has increased environmental pollution and affected ichthyofauna in the watersheds where they are used. We studied the effect of an herbicide, triazine, on the kidneys of two species (Caquetaia kraussii and Colossomna macropomum) widely found in Caribbean and South American rivers. In Venezuela, these species are abundant and have a high aquaculture potential because they may be cultured and reproduced in captivity. Four kidney samples from juveniles of each species exposed to the herbicide were examined by Transmission Electron Microscopy. Kidney tubule alterations included loss of plasmalemma and cell interdigitations, misshaped mitochondria, decrease in rough endoplasmic reticulum and free polysomes, and the presence of autophagic vacuoles and primary lysosomes. These alterations at the cellular level may explain fish behaviour in terms of kidney tubule pathology, and relative amounts and conditions of organelles within affected cells.

Skeletal muscle ultrastructural pathology in mice infected with Trypanosoma evansi.

An ultrastructural study of skeletal muscle alterations wascarried out in mice experimentally infected with Trypanosoma evansi. Manifested anomalies were found, in both muscle fibre and microvasculature. Muscle fibre changes included atrophy, autophagic vacuoles formation, mitochondrial degeneration, nuclei pyknosis and segmental necrosis. In another direction, the cytoplasm of capillary endothelial cells showed rough endoplasmic reticulum and mitochondrial swelling, as well as luminal infoldings; parasites were found in the endothelial cell cytoplasm. A mononuclear infiltrate, formed by macrophages and neutrophils, was also observed. This work shows that skeletal muscle is an important target tissue for Trypanosoma evansi.

Ultrastructural alterations in the adrenal gland cortex of mice experimentally infected with a Venezuelan isolate of Trypanosoma evansi.

The ultrastructural study of adrenal gland from mice experimentally infected with Trypanosoma evansi, in addition to intravascular and intracellular trypanosomes, showed different degrees of cortical cell alterations and capillary wall modifications. Beside its biological scope, these results suggest a role for the adrenal cortex to partake in Surra's etiopathogenesis and describe for the very first time a T. evansi intracellular stage.