Protective Effects Of AFGF And MaFGF On Acute Renal Failure Of Rats In Vivo And In Vitro

Objective:Acute renal failure(ARF)is a serious clinic syndrome,currently no drastic management is available to improve the renal function other than dialysis. Ischemia-reperfusion injury and pharmacal nephrotoxicity(for example aminoglycoside antibiotics nephrotoxicity)are both of the most common reason of ARF.The pathophysiologic abnormalities of ARF reflect the epithelial cell of renal proximal tubule and medullary thick ascending limb of Henle's loop injury. Therefore,it is important that to promote the impair renal epithelial cell reactivate.This experimental work is aimed to(1)Study the protective effect of aFGF and MaFGF on renal ischemia/reperfusion injury of rats.(2)Investigate the protective role of MaFGF in the injury of GM on cultured renal tubular epithelial cells.Methods1.In Vivo Experiment:48 wistar rats were divided randomly into six groups; false operative control group,model control group,8μg·kg^-1of aFGF and 16μg·kg^-1of aFGF groups,8μg·kg^-1of MaFGF and 16μg·kg^-1of MaFGF groups with 8 animals in each group.The model of renal ischemia-reperfusion in rat was set up with clamping both renal artery inducing kidney ischemia for 45 min and following reperfusing in situ.The animals were sacrificed at 24h after reperfusion,so the bilateral kidney and blood sample were collected.The blood urea nitrogen(BUN)and serum creatinine(Scr)were measured on automatic biochemistry analyzer.The levels of malondialdehyde(MDA),nitric oxide(NO),the activities of antioxidant enzymes in the renal tissue including superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)and the serum MDA were assayed.The renal pathological changes were observed by light and electron microscope.DNA ladder were examined by DNA agarose gel eletronphores.2.In Vitro Experiment:These primary cells were obtained through digestion by pamcreatin and inoculated into 96 well plates.(1)A series of concentrations of MaFGF were added into DMEM.Cell viabilities were tested by WST-8 assay after 72 hours culture.(2)After 72 culture,a series of concentrations of gentamycin(GM)were added.Incubation 12 hours,adding different concentrations MaFGF to experimental groups.WST-8 method was performed to test cell viability after treated in 48 hours.(3)The injury model was established by GM,and MaFGF was added after 12 hours.The protective role of MaFGF in the injured renal tubular epithelial cells was observed.Result1.In Vivo Experiment:Comparing aFGF groups and MaFGF groups with model control group,the levels of serum BUN,Scr,MDA and tissue MDA,NO are decreasing,the activities of SOD and CAT are increasing(P＜0.01 or 0.05).As shows of pathology,compared with model group,aFGF groups and MaFGF groups could significantly reduce edema,number of leukocytes appearing in the interstitium,distention and destroy of renal tissue.Under EM,the ultrostructure (including microvilli,mitochondria and lysosomes etc.)of the tubular epithelial cells of aFGF groups and MaFGF groups appeared lighter in injuries or even near normal.The model group exhibited diffusion DNA ladder in the DNA agarose gel eletronphores,while the aFGF groups and MaFGF groups exhibited single clear DNA ladder.2.In Vitro Experiment:(1)MaFGF could enhance the renal tubular epithelial cell multiplitation.(2)The concentrations of GM that inhibited 50%cell growth (IC50)were increased up by aFGF.(3)The differences of the contents of biochemistry and enzymology between GM group and control group were significant(P＜0.01 or 0.05).It is also significant(P＜0.01 or 0.05)between MaFGF+GM group and GM group.However the differences of NO content between MaFGF+GM group and control group are insignificant(P＞0.05),but the change of MDA and the activity of SOD,GSH-Px is still significant(P＜0.05 or 0.01).Conclusion:aFGF and MaFGF have a role in attenuation of renal damage or failure after ischemia-reperfusion or GM injury of the kidney.The mechanisms that aFGF and MaFGF protect renal structure and function from AFR may be related to eliminating oxyradicals effectively,reducing lipid peroxidation, increasing antioxidant enzymes activity.