Modulation of toxic effects of ammonia on growth, pathology of liver and kidney tissues and relative expression of GH and IGF-1 Genes by CoQ 10 Supplementation in Oncorhynchus mykiss.

Reducing the negative impact of environmental and stressful factors is a crucial step in achieving sustainable aquaculture. Therefore, a study was aimed at evaluating the impacts of Coenzyme Q 10 (CoQ 10 ) supplementation on growth, relative gene expression of Growth Hormone (GH) and Insulin-like growth factor-1 (IGF-1), liver and kidney histopathology against stress induced by ammonia in Rainbow trout (Oncorhynchus mykiss). The fish were given feed containing different levels of CoQ 10 for 8 weeks: Control - CoQ 10 0%, G1 - CoQ 10 0.1%, G2 - CoQ 10 0.5% and G3 - CoQ 10 1%. At the end of the experiment, fish were exposed to ammonia stress concentration at 0.6mg/L for 24 h to assess liver and kidney tissue damage. Results showed that there was a significant activity increase in GH and IGF-1 genes due to supplementation with CoQ 10 alone (p < 0.05). Gene expression for GH increased about two-fold whereas that for IGF-1 experienced a four-fold upregulation compared to controls (p < 0.05). CoQ 10 's-related antioxidant effects probably minimized liver and kidney cellular injuries, as significant decreases were observed in ammonia-induced mortality (p < 0.05). In summary, adding CoQ 10 to the diet is a potential way to improve fish production through controlling the gene expression of GH and IGF-1, as well as making fish populations more resistant to possible future stress caused by ammonia in intensive or super-intensive aquaculture systems.