| Objective:Paraquat(PQ) has been widely used as a contact herbicide of organism heterocycle throughout the world. Along with the widespread use of paraquat in our country,PQ poisoning is becoming a more and more serious clinical problem.PQ is highly toxic to human beings and animals. It is readily absorbed through skin , pneogaster or enteron. The human lethal oral dose is very small.While the poisoning mechanism has not been fully elucidated, and there are not effective pharmacological antagonists for paraquat heretofore. There is a high mortality rate in poisoning cases.PQ is excreted as the original form from the renal, this is the main cause of renal damage. The exact mechanism of renal kenosis and renal toxicity of PQ has not been fully enunciated. Through determining content of BUN,Cr in serum and malonyldialdehyde(MDA), activity of superoxide dismutase (SOD),glutathione peroxidase (GSH-Px) in renal tissue, observing the ultrastructure variation by HE staining and the expressions of HGF,TGF-β1 in the rat model of paraquat-induced renal acute injury by the method of immunohisto-chemistry, to explore the possible mechanism and assess the protective effect of Hepatocyte Growth-promoting Factors(pHGF)in PQ poisoning.Methods: one hundred and eight adult healthy Sprague-Dawley(SD) rats(54female, 54male),were divided into three groups randomly.(1)Control group (group A): 36 rats ,(2)Poisoned group (group B): 36rats ,(3)pHGF group(group C): 36 rats.Group B and C were treated intraperitoneally with 1ml of PQ (25mg/kg) diluted with normal saline. Group A were treated with the same dose of normal saline as group B and C.Group C were given 1 ml of pHGF at a dose of 1mg/kg diluted with normal saline (once every 12h, intraperitoneally) immediately after the administration of the PQ. Group B were treated with the same dose of normal saline (once every 12h, intraperitoneally) as group C.Six rats in group A,B,C were killed and thoracotomy by ether anaesthesi on 1st day, 3rd day, 5thday,7thday,10thday,14thday,after paraquat treatment respectively, then taken blood samples from abdominal aorta to detect Serum levels of BUN,Cr ,and taken renal tissue samples was quickly to measure SOD, GSH-Px activity and MDA concentration; We used the reliquus renal tissue for HE staining and to detect the expression of HGF,TGF-β1 of renal by immunohistochemistry (IH) staining.Results:1. rats intoxication manifestations :the appearance occurred in rats only 0.5~2 hours after PQ poisoning, Intoxication involves a combination of signs and symptoms that included lassitude,lethargy,restlessness,appetite badly, breathlessness, dyspnea, cyanosis,hematuria, oliguresis, anuresis, ataxia, convulsions, unhairing,nose and/or eyes bleeding. As compared with Group B, rats in Group C demonstrated the intoxication manifestations were relieved obviously, especially the symptoms of dyspnea and hematuria, oliguresis, anuresis.2.Renal tissue histological changes:(1)appearance findings:Group A There were no abnormal in Group A;Group B: the renal obviously distension and the surface have bleeding point or ecchymosis;Group C:after pHGF treatment ,the renal distension relieves and have no bleeding point or ecchymosis.(2)HE staining:Group A:there were no abnormal in every parts structure of renal;Group B:①Renal glomerulus:had hyperemia and distension;②Renal tubule epith elial cell had edema and vacuolar degeneration and renal tubule lumina was narrowing on 1st day,There were edema exudation and necrosis and in the tubule lumina have particulate of cellular necrosis on3rd day ,There were serious edema exudation and necrosis on 5~7thday, which gradually lessened.③Inflammatory cell infiltration and hyperaemia appear in renal interstitial;Group C:pHGF significantly alleviated the acute renal pathological changes in these rats of PQ poisoning.3.Serum measurement:①Group A:the contents of BUN and Cr were normal;②Group B:BUN were manifest to advance on 1st day,to reach peak on 3rd day, 1st ~5th day were significantly lower than that in group A (P<0.05),which gradually lessened .Cr changed have no statistical significance.③Group C:after HGF treatment,1st~3rd day the contents of BUN were lower than that in group B (P<0.05), and no statistical differences after 3rd day between group B and C (P>0.05);but still higher than Group A (P<0.05), there were no statistical differences after 3rd day between group A and C (P>0.05), Cr changed have no statistical significance.4.Renal tissue measurement: (1)MDA measurement:①Group B:The levels of MDA in group B were significantly higher than that in group A on the 1st, 3rd, 5th day (P<0.01);②Group C:Whereas the increases of renal tissue MDA were markedly intibited in group C, in which, the levels of renal tissue MDA in all these time points were significantly lower than that group B (P<0.05), Compared with that of group A, the statistically significantly higher levels of it in group C only kept on the 1st, 3rd day (P<0.05).⑵SOD measurement:①G roup B:The activity of renal tissue SOD in group B were significantly lower versus that in group A on the 1st, 3rd day(P<0.01), on the 5th, 7th day (P<0.05);②group C: compared with that of group B, The levels of SOD activity were increased in group C on the 1st, 3rd, 5th , 7th day(P<0.05);compared with that of group A the statistically lower levels of it in group C only kept on the 1st, 3rd day (P<0.01).⑶GSH-Px measurement:①Group B:The activity of GSH-Px in group B were significantly lower than that in group A on the 1st, 3rd day (P<0.05);②Group C:the activity of GSH-Px in group C remarkably increased, and was higher than that in group B on the 1st, 3rd day (P<0.01), but there were no statistical differences all the time points between group A and C (P>0.05).5.Immunohistochemistry (IH) staining:(1)HGF:There was a very weak expression of HGF in group A. while in group B, there was already a significant higher expression of HGF in renal tubule on 1st day after PQ poisoning (P<0.01), which reached the peak on 3rd day(P<0.01), and gradually decreased furthermore but remained higher than that in group A on 5~7th day (P<0.05), but there were no statistical differences after on 10~14th day between group A and group B (P>0.05) ;The expression of HGF in group C was significant higher than that of group B on day 1st~7th day (P<0.01), on 10~14th day still higher than that of group B(P<0.05);But the expression of HGF in group C was significant higher than that of group A on 1st~7th day(P<0.01), and still higher than that group A on 10~14th day(P<0.05);②TGF-β1:There was only a very weak expression of TGF-β1 of renal tubule and was no expression of renal glomerulus in group A;while in group B, there was already a significant higher expression of TGF-β1 of renal tubule on 1st day after PQ poisoning, while it kept in a sustained significant higher level in group B compared with group A on 1st ~10th day (P<0.01), and still higher then that group A on 14th (P<0.05);while the expression of TGF-β1 of renal tubule in group C was higher than that of group B on day1st~14th day (P<0.05), compared with group A significant higher in group C on 1st~7th day (P<0.01), and still higher than that group A on10~14th (P<0.05).Conclusions:①PQ intraperitoneally poisoning can induce acute renal injury and principal display the damage of renal tubule endothelial cell, PQ intraperitoneally poisoning was a reliable method of making a model of acute renal injury;②PQ poisoning possible to cause blood serum of BUN to heighten, but Cr changed have no statistical significance;③Oxidative insult was one of the main mechanisms of PQ-induced renal injury;④HGF and TGF-β1 were mainly expressed in renal tubule and the excess expression were possibly important factors of renal injury and recovery;⑤pHGF treatment decreased significantly the content of MDA in PQ poisoning rats and increased significantly the activity of SOD and GSH-Px to alleviate the renal injury;⑥pHGF may directly enhancement the externalization and expression of HGF/C-met and indirectly inhibit the expression of TGF-β1 thereby alleviated the renal injury.
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