Study On Alleviation Of Transport Stress In Cyprinus Carpio By Adding Vitamin C To Water

In this paper, we comprehensively analyzed the mechanism of transport stress, and alleviate the adverse effect of ammonia and transport stress by adding vitamin C to water. It provides a new train of thought and research direction in solving the problem of transport stress with important application significance.The main research contents and results are as follows:1. The study of relief to acute toxicity of ammonia in common carp by adding vitamin C to water. In order to study the alleviation of oxidative stress in fish, we selected the ammonia as the important source of stress during transportation and aquaculture to set up the model of oxidative stress. At first, we studied the acute toxicity of ammonia to common carp. The 96 h ammonia minimum lethal concentration was 145 mg/L(3.00 mg/L NH3-N, un-ionized ammonia); 96 h LC50 values for total ammonia-N(TA-N) were 79.75 mg/L(1.65 mg/L NH3-N, un-ionized ammonia). Secondly, different vitamin C concentrations were in addition to water under 96 h ammonia minimum lethal concentration(145 mg/L), and all the fish lived during 96 h with 30 mg/L vitamin C concentrations. And vitamin C could remain stable for 6 h during the experiment. An elevation of plasma vitamin C concentrations was found in the common carp.2. The mechanism study of relief to oxidative stress in common carp by adding vitamin C to water. We used ammonia stress to set up the model of oxidative stress, common carp were exposed to an ammonia-N concentration corresponding to 50% of the 96 h LC50 value(40 mg/L TA-N or 0.83 mg/L NH3-N) for 96 h with(alleviation group) or without(model group) the addition of vitamin C(25 mg/L) to the water. We set the control group(0 mg/L), model group(40 mg/L) and alleviation group(40 mg/L+25 mg/L Vc). The results indicated that, after 12, 24, 48 and 96 h ammonia stress, the plasma biochemistry index such as plasma cortisol and glucose concentrations, activities of plasma ALT, AST and AKP, anti-oxidation index such as activities of SOD and CAT, MDA concentrations and liver HSP70 gene expression were significantly increased compared to the control group. With the increase of exposure time, the structure of gill tissues was severely damaged. The changes of indexes above indicated that ammonia stress could induce oxidative stress in common carp and affect the normal physiological state of common carp. It meant that the model of oxidative stress was set up successfully in the experiment. Compared to the model group, the indexes of alleviation group with vitamin C were significantly decreased at different exposure time. The structure of gill tissues in alleviation group was lesser damage than model group. It could indicate that vitamin C added to water could alleviate the oxidative stress caused by ammonia stress to reduce the oxidative injury.3. The study of relief to transport stress in common carp by adding vitamin C to water. The study set up a control group, model group and Vc alleviation groups(25 mg/L). The model group and alleviation group transport 5 h at the speed of 60 km/h under the density of 200 g/L. After 5 h transportation, the plasma biochemistry index such as plasma cortisol and glucose concentrations, activities of plasma ALT, AST and AKP, anti-oxidation index such as activities of SOD, CAT and GSH-PX, MDA concentrations and liver HSP70 and HSP90 gene expression were significantly increased compared to the control group. The liver TNF-α gene expression was not significantly changed. The structure of gill tissues was severely damaged. The structure of muscle was significantly changed. It indicated that transport stress could induce oxidative stress and adverse effect in common carp, and cause the oxidative injury. Compared to the model group, plasma cortisol and glucose concentrations, activities of plasma ALT, AST and AKP were significantly decreased. The activities of SOD,CAT and MDA concentrations were also much lower than the model group. Liver HSP70 gene expression of common carp in alleviation group was significantly decreased, HSP90 gene expression were not significantly changed. The liver TNF-α gene expression was significantly increased. The structure of gill tissues in alleviation group was not damaged. The function of the structure is fully.The above results showed that the transport stress could induce adverse effect on the common carp and oxidative stress. Vitamin C added to the water could go into the body of common carp and alleviate the oxidative stress, and alleviate the oxidative injury.