The Protective Effects And Mechanisms Of Reduced Glutathione On Acute Kidney Injury Induced By Glycerol In Rats

Objective:In this study, acute kidney injury models induced by glycerol were used to investigate the protective effects and mechanisms of reduced glutathione on acute kidney injury in rats.Methods:Forty-eight healthy Sprague-Dawley (SD) male rats were randomly divided into three groups-control group (normal group), model group (glycerol injection group), the intervention group (reduced glutathione treatment group), each group contained 16 rats. Weighing and recording the weight of the rats. The control group were injected 0.9% saline into the hind limbs muscle with the injected dose of 10ml/kg. The model group and intervention group were injected 50% glycerol saline into the hind limbs muscle with the injected dose of 10ml/kg. In the two hours before injecting 50% glycerol saline into the hind limbs muscle, the intervention groups were injected reduced glutathione (Gluthion) into enterocoelia with 150mg / kg (1g of reduced glutathione dissolved in 33.3mL saline). According to the time of injection, each group was divided into two subunits (24h, 48h subunits). Each subunit contained 8 rats. End of the experiment, 5ml blood was draw from the inferior vena cava under anesthesia and was placed into the centrifuge tube. The samples were centrifuged for 10 minutes (3000r/min), and the supernate were kept in -20℃to preserve. Rats were killed after being blooded. Removed both kidneys and observed the changes of the color and size. To observe the pathology morphological changes of the kidneys, they were stripped the renal capsule, split longitudinally, and were kept in 10% neutral formalin solution in 4℃to fixed and stained with hematoxylin-eosin (HE). The blood urea nitrogen (BUN) by diacetylmonoxime method, the serum creatinine (SCR) by picric acid method, the malondialdehyde (MDA)by thiobarbituric acid determination, superoxide dismutase of the total enzyme (SOD)by hydroxyl amine method, and creatine kinase (CK) changes by colorimetric determination. Results:1. There was no adverse reaction occurred to the control group.After being injected the glycerol, the local muscles of the model rats were edema, dark red urine appeared after 1 hour, spiritual malaise, unresponsive, was curled up like,the bodies hair were yellow, and the rats refused to diet and water. and the urine reduced. The symptoms of intervention group lighten clearly compared with the model group.2. The model group: the blood Bun, Scr, MDA, CK levels is significantly higher than the control group (p<0.05), and SOD significantly decreased (p<0.05). The intervention group: blood Bun, Scr, MDA, CK levels were lower (p< 0.05) than model group, but still higher than those in the control group (p < 0.05), and SOD levels were higher (p < 0.05) than model group, but lower than those in the control group (p < 0.05). Control group and intervention group within 24h group and 48 hours group, Scr, blood Bun MDA, CK, SOD compared have no significant difference (p > 0.05). The blood BUN, Scr, of MDA, CK level in the 48 hours group were significantly increased compared with 24 hours in the model group (p < 0.05), SOD significantly reduced (p < 0.05).3. Histological changes of Renal, in the model group, glomerular swelled, distal lumen expanded, and renal tubular epithelial cells degenerated and mortified, covered with protein casts, in particular the junction of the skin and Medullary,outside the intramedullary lesion .In intervention group, glomerular and tubular structural integritied, cell mild degenerated, swelled, and proliferated significantly, a small amount of luminal expanded.Conclusions:1.In the model group adter injecting Glycerol,glomerular swelled, distal lumen expanded, and covered with protein casts, and cell tube visible. In intervention group, glomerular and tubular structural integritied, cell mild degenerated, swelled, proliferated significantly, a small amount of luminal expanded.2. BUN, Scr, MDA, CK levels in intervention group was lower than model group, while SOD in intervention group was significantly higher than model group. In model group, BUN, Scr, MDA, CK in 48h group were significantly higher than 24h group, SOD was significantly decreased .It showed that glutathione played a protective effection on renal function and renal structure by reducing the production of peroxide in vivo after reaction with radicals.