Effect of bilirubin on the anti-oxidative stress ability of red cell membrane in rats undergoing high intensity training

AIM:To observe the effect of supplementing bilirubin on the anti-oxidative stress ability of red cell membrane in training rats through establishing animal models of high-intensity training. METHODS:The experiment was performed in the physiological laboratory of Physical Institute of Jiangxi Normal University from December 2004 to January 2005.①After one week of adaptive feeding,24 male SD rats were randomly divided into quiet control group,high intensity sports training and physiological saline group(training group),high intensity sports training and bilirubin group(training and supplementing group)with 8 animals in each group.②The training group and the training and supplementing group did the running on the platform with the slope of 0°at the first three weeks and 5°at the fourth week,6 days every week expect Sunday.The training and supplementing group was intragastrically infused with bilirubin by 40mg/kg body mass at 17:00-18:00 after training every day,and the other groups were given physiological saline,six times every week.Anticoagulatory blood about 2mL of heparin was harvested to prepare red cell membrane sample and measure the relevant indexes on the 4~(th)Sunday.③The serum total bilirubin level was determined using automatic biochemical analysis instrument;the malondialdehyde(MDA)and glutathione peroxidase(GSH-Px)of red cell membrane by TBA;the activity of superoxide dismutase(SOD)of red cell membrane using the method of Xanthine oxidase.All the treatment for animals was based on the ethical standards. RESULTS:All 24 rats were involved in the result analysis.①The serum total bilirubin level in training group was lower than quiet control group(P0.01),and the supplementing group(P0.01).But there was no significance between control group and training and supplementing group(P0.05).②The MDA of the red cell membrane in the training group was higher than the control and training and supplementing group(P0.01),but there was no statistical difference between control group and training and supplementing group(P0.05).③The activity of SOD in training group was lower than quiet control group(P0.01),and the supplementing group was higher than training group(P0.01)and control group(P0.05).④No difference was found in the activity of GSH-Px of red cell membrane between the control group and the training group(P0.05),but the training and supplementing group was higher than the control group and the training group(P0.05). CONCLUSION:Supplementing exogenous bilirubin can inhibit the increase in the MDA content of red cell membrane in rats caused by high-intensity training for a long time,and also improve the activity of SOD and GSH-Px in the same time.The mechanism of anti-oxidant function of bilirubin is perhaps correlated with its characteristic of offering hydrogen of the chemical constitution foundation.