Induction of nitric oxide synthesis: a strategy to defend against high environmental ammonia-induced oxidative stress in primary hepatocytes of air-breathing catfish, .

Air-breathing magur catfish () regularly face the problem of exposure to high environmental ammonia (HEA) as one of the major pollutants in their natural habitats that causes considerable toxic effects at the cellular level, including that of oxidative stress. The major objective of the present study was to demonstrate the antioxidant activity of endogenously produced nitric oxide (NO) to defend against ammonia-induced oxidative stress in primary hepatocytes of magur catfish during exposure to HEA. Exposure to NHCl (5 mmol l) led to a significant increase in intracellular ammonia concentration with a sharp rise of hydrogen peroxide (HO) and malondialdehyde (MDA) concentrations within 3 h in primary hepatocytes, which decreased gradually at later stages of treatment.

Molecular characterization and ornithine-urea cycle genes expression in air-breathing magur catfish (Clarias magur) during exposure to high external ammonia.

The air-breathing magur catfish (Clarias magur) is a potential ureogenic teleost because of its functional ornithine-urea cycle (OUC), unlike typical freshwater teleosts. The ability to convert ammonia waste to urea was a significant step towards land-based life forms from aquatic predecessors. Here we investigated the molecular characterization of some OUC genes and the molecular basis of stimulation of ureogenesis via the OUC in magur catfish.

Transcriptome analysis reveals novel insights in air-breathing magur catfish (Clarias magur) in response to high environmental ammonia.

The facultative air-breathing magur catfish (Clarias magur) frequently face different environmental challenges, such as hyper-ammonia, and desiccation stresses in their natural habitats. All these stresses lead to higher accumulation of body ammonia, thereby causing various harmful effects to the fish due to its toxicity. Nonetheless, the mechanisms underlying ammonia-induced toxicity is yet not clear.

Antioxidant activity of endogenously produced nitric oxide against the zinc oxide nanoparticle-induced oxidative stress in primary hepatocytes of air-breathing catfish, Clarias magur.

The facultative air-breathing magur catfish (Clarias magur) regularly encounter various environmental challenges including the exposure to nanomaterials discarded as industrial wastes in water bodies. The present investigation aimed at determining the possible ZnO NP-induced oxidative stress and also the antioxidant strategy of nitric oxide (NO), generated endogenously, in primary hepatocytes of magur catfish. Exposure of primary hepatocytes to different concentrations of ZnO NPs (5 and 10 μg/mL) led to a sharp rise of intracellular concentrations of hydrogen peroxide (HO) and malondialdehyde (MDA) within 6 h, which decreased gradually at later stages.