Effects Of Guanidine Acetic Acid On Skeletal Muscle Cells And Nursery Pigs

In this paper,we studied effects of guanidine acetic acid on antioxidant-related and carbohydrate metabolism-related enzymes activity in skeletal muscle cells under oxidative stress,and on production performance,antioxidant capacity and the enzymes of glucose metabolism in nursery pigs.The three tests following were conducted:1.Inductions of the oxidative stress by hydrogen peroxide in skeletal muscle cells.In this study,the oxidative stress injury model was established by adding different concentrations of 0?CON?,0.2?H2?,0.4?H4?and 0.8?H8?mM H₂O₂ for 0.5 h and 1.5 h to skeletal muscle cells,in order to detect the proliferation of cells and the changes of antioxidant enzymes.The results showed that:?1?Cell proliferation rate in 3 H₂O₂-added groups was significantly lower than that of the control group?P<0.05?.At the stress time of 0.5 h,the cell proliferation rate of H2,H4and H8 groups was very significantly decreased compared with the control group?P<0.01?.At the stress time of 1.5 h,compared with the control group,the cell proliferation rate of H2,H4 and H8 groups also decreased very significantly?P<0.01?,which rate of decline was much higher than that of the stress time0.5 h with a large number of cell deaths observed.So we chose stress time of 0.5 h for the following trials.?2?Compared with the control group,there was no significant change in Superoxide Dismutase?SOD?inhibition rate?P>0.05?in H2,but the inhibition rate of SOD in H4 and H8 groups was significantly decreased?P<0.05?in skeletal muscle cells.There was no significant change in Glutathione?GSH?content?P>0.05?.So 0.4 mM H₂O₂ and 0.5 h stress time were selected to establish cell oxidative stress model.2.Effects of guanidine acetic acid on skeletal muscle cells under H₂O₂ induced oxidative stress.This experiment was conducted to study effects of guanidine acetic acid on skeletal muscle cells under H₂O₂ induced oxidative stress.We divided skeletal muscle cells into CON?control group?,G10?10 mmol/L GAA?,G20?20 mmol/L GAA?,H4?0.4 mM H₂O₂?,H4G10?0.4 mM H₂O₂+10 mmol/L GAA?,H4G20?0.4 mM H₂O₂+20 mmol/L GAA?.The activity of antioxidant enzymes and glucose metabolism-related enzymes,intracellular ROS and apoptosis rate were detected.The results showed that:?1?Under the physiological condition,guanidine acetic acid had no significant effects on SOD activity and GSH content in skeletal muscle cells?P>0.05?.Under oxidative stress conditions,guanidine acetic acid can improve SOD activity?P<0.05?,reduce the level of intracellular Reactive Oxygen Species?ROS?and the apoptosis rate to alleviate oxidative stress induced by H₂O₂.?2?Under the physiological condition,guanidine acetic acid have significant effects on glucose metabolism-related enzymes?Pyruvate Kinase?PK?and Malate Dehydrogenase?MDH???P<0.05?,but under H₂O₂ stress no significant effects on glucose metabolism-related enzymes detected were found?P>0.05?.3.Effects of guanidine acetic acid on production performance,antioxidant capacity and the key enzymes of glucose metabolism of nursery pigs.64 healthy piglets?19.03±1.30 kg?were randomly divided into two groups.Four replicates per group,each repeating 8 pigs.The control group?Control,CON?:fed basal diet;Guanidine acetic acid?GAA?:600 mg/kg guanidine acetic acid was added to the basal diet.Each group randomly selected 8 pigs,for blood collection.During the 14 days of the experiment,body weight,average intake,plasma antioxidant enzyme levels or activity and plasma energy metabolism-related enzymes activity were determined.The results showed as follows:?1?Compared with the control group,the average daily gain?ADG?of guanidine acetic acid group was significantly increased?P<0.05?,and the feed-meat ratio?F/G?significantly decreased?P<0.05?.There was no significant difference between the two groups?P>0.05?in the body weight and average daily feed intake?ADFI??P>0.05?.?2?The inhibition rate of SOD,GSH content and Total antioxidant capacity in guanidine acetic acid group was significantly higher than that in control group?P<0.01?,and the content of MDA?Malondialdehyde?in control group and guanidine acetic acid group was not significantly different?P>0.05?.?3?The activity of Fructose-6-phosphate Kinase?PFK?,PK,Isocitrate Dehydrogenase?IDH?,MDH,NADH-coenzyme Q reductase?NADH-CoQ?and Creatine Kinase?CK?of guanidine acetic acid group were significantly higher than the control group?P<0.01?,the trend of HK?Hexokinase?and ATPase?ATP synthase?activity in guanidine acetic acid group is higher than the control group?P<0.10?.Conclusions?1?Under normal conditions,guanidine acetic acid had no significant effects on the antioxidant capacity in skeletal muscle cells.Under oxidative stress conditions,guanidine acetic acid can increase the SOD activity,reduce the ROS level and the ratio of apoptosis in skeletal muscle cells,to alleviate H₂O₂-induced oxidative stress.?2?Under normal conditions,guanidine acetic acid can improve glucose metabolism related enzymes?PK,MDH?activity to promote glucose metabolism.Under oxidative stress conditions,guanidine acetic acid had no significant effects on the activity of glucose metabolism related enzymes?HK,PFK,PK,MDH?.?3?Addition of guanidine acetic acid in diet can increase the activity of glucose metabolism enzymes?HK,PFK,PK,IDH,MDH,NADH-CoQ and ATPase?to promote the body catabolism,so as to improve the body ATP levels.