Acute paraquat exposure determines dose‐dependent oxidative injury of multiple organs and metabolic dysfunction in rats: impact on exercise tolerance

Abstract

This study investigated the pathological morphofunctional adaptations related to the imbalance of exercise tolerance triggered by paraquat (PQ) exposure in rats. The rats were randomized into four groups with eight animals each: (a) SAL (control): 0.5 ml of 0.9% NaCl solution; (b) PQ10: PQ 10 mg/kg; (c) PQ20: PQ 20 mg/kg; and (d) PQ30: PQ 30 mg/kg. Each group received a single injection of PQ. After 72 hours, the animals were subjected to an incremental aerobic running test until fatigue in order to determine exercise tolerance, blood glucose and lactate levels. After the next 24 h, lung, liver and skeletal muscle were collected for biometric, biochemical and morphological analyses. The animals exposed to PQ exhibited a significant anticipation of anaerobic metabolism during the incremental aerobic running test, a reduction in exercise tolerance and blood glucose levels as well as increased blood lactate levels during exercise compared to control animals. PQ exposure increased serum transaminase levels and reduced the glycogen contents in liver tissue and skeletal muscles. In the lung, the liver and the skeletal muscle, PQ exposure also increased the contents of malondialdehyde, protein carbonyl, 8-hydroxy-2'-deoxyguanosine, superoxide dismutase and catalase, as well as a structural remodelling compared to the control group. All these changes were dose-dependent. Reduced exercise tolerance after PQ exposure was potentially influenced by pathological remodelling of multiple organs, in which glycogen depletion in the liver and skeletal muscle and the imbalance of glucose metabolism coexist with the induction of lipid, protein and DNA oxidation, a destructive process not counteracted by the upregulation of endogenous antioxidant enzymes.

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“…The significantly higher AST, LDH, and ALT activities in the fish exposed to increasing atrazine across the treatment when compared with control groups could be as a result of leakage of aminotransferase (AT) enzymes from injured liver cells. These results were similar to that of Konstantinova & Russanov, (1999) who studied paraquat induced oxidative stress in rat liver. The increase in the value of the enzymes activity may be as a result of extra-cellular fluid as reported by Akanji, Olagoke, & Oloyede (1993) Both the AST and ALT are enzymes connected with liver parenchymal cells.…”

Antioxidant and Anti‐Inflammatory Effects of Anacardium occidentale L. and Anacardium microcarpum D. Extracts on the Liver of IL‐10 Knockout Mice

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Strychnos pseudoquina modulates the morphological reorganization of the scar tissue of second intention cutaneous wounds in rats

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