Effect of transport stress on physiological-biochemical indices and expression of HPI genes and roles of glycyrrhizin on transport response in Coilia nasus

Abstract:

In this study, we selected Coilia nasus as the research object, and we studied the effect of transport response on mRNA level of hypothalamus-pituitary-interrenal axis (HPI) genes and liver oxidative indices, using qRT-PCR and biochemistry method. Meanwhile, Coilia nasus were soaked with a certain concentration of glycyrrhizin (GL) to investigate the regulation of the above indices during transportation. The results showed that corticotropin releasing hormone (CRH) mRNA, proopiomelanocortin (POMC) mRNA and urotensin I (UI) mRNA expression in brain were significantly suppressed after transportation. Glucocorticoid receptor (GR) mRNA expression in head kidney decreased significantly at 2 h and reached the minimum at 4 h, then increased obviously at 8h. After transportation, Catalase (CAT) activities in liver decreased significantly, the level of malonaldehyde (MDA) in liver rose dramatically, glutathione peroxidase (GSH-PX) activities and the lipid peroxide (LPO) content of liver had no significant change. After 6 h, glycyrrhizin suppressed distinctly the level of GR mRNA in head kidney, and inversely stimulated CRH mRNA and POMC mRNA expression of brain with significant difference, but UI mRNA expression in brain had no obvious change. Moreover, glycyrrhizin had no significant effect on the activities of CAT and GSH-PX and the content of MDA and LPO. All the results above indicated that levels of HPI genes expression were changed to different extent after transportation. Transport response reduced hepatic anti-oxidative capacity and caused oxidative stress in Coilia nasus. Likewise, glycyrrhizin can regulate the expression of HPI genes, but it can't effectively relieve oxidative stress caused by transport stress.