| Abnormality of lipid metabolism are often seett in many kidney diseases, It'swell Anown that hyperlipidemia not only is one of a clinical feature of kidneydiseases but also could contribute to occurance and development of kidney diseases.Recently, it's reported that plasma TG level and triglycerid-rich lipoproteins arecorrelated with urinary albumin excretion and declil1e of renal function respectively,suggesting such lipoproteins may play a crucial role in kidney diseases. However,it's can't be confirmed whether hypertriglyceridemia or VLDL can cause renal injuryup to now not to mention the real pathophysical raechanism. In light of these, weintend to prove that hypertriglyceridemia may induced renal injury ofuninephrestomized Sprague-Dawley rats, to invetig11te the mechanism of such injuryand if lipid-lowing agent can do benefit to renal iEjury Furthermore, rat mesangialcells in vitro wlI be cultured with VLDL, and thel1 investigate the effect of VLDLon cell prolifefaion, fibronectin production, TGF- )3 l expression ofmesangial cellsand the role of P42 MAPK played in these effect. By means of these, the molecularbiological mechanism ofnephrotoxity of VLDL wi1l be discussed.Methodl. In vivo part(l) All male Sprague-Dawley rats were perfOrmed left-uninephrestomy andseParated into fOur groups at random: Experimental group(Exp ), ColltrolgrouP(Con), fibrozilGem grouP(Gem) and Axaloside group (Ara)(2) Fasting blood of all rats were sampled, an(l serum lipid, creatinine, urea andglucose level were assayed when these rats were breed for 8,l6 weeks. Atsame time, UAE was also measured.(3) Renal pathologic examination: Oil red-O stain by Which to observe lipiddeposition. And pathologic changes wit11in kidney were investigated bymicroscope and Electric microscope. Also immunofluorescence andimmunohistochemistry were employed to investigate immuno complexdeposition and cell proliferation within the residual kidney Furthermore,cellular number and the percefltage oiF PAS positive material withinglomeruli were half quantified.(4) RT-PCR and Wetern Blot were used to measured mRNA transcription andprotein expression of TGF- 6 l respectively.(5) P42 MAPK activity of renal cortex was also determined by isotope labeledmethod.(6) Correlation anaIysis between serum lipid with UAE, p42 MAPK activity,mean ce1l number and percentage of PAS positive material withinglomeruli.2. In vitro part:Rat mesangial cells were investigated as object and were cultured Wth VLDLprepared by ultraspeed centrifuged. And some experiment have been done as fOllow:(l) XTT assays and Flow-cytometery were employed to determined cellproliferation and proliferative index respectively.(2) Protein production of fibronectin of mesangial cells was measured byELISA method.(3) Protein expression and mRNA transcription of TGF- 6 l were assayed byWestem Blot and RT-PCR respectively(4) Isotope labeled method was taken to measu]red P42 MAPK activity.(5) All the experiments mentioned above were repeated after P42 MAPK hadbeen blocked by PD98059.Result:l. In vivo part(l) Serum TG, VLDL level of Exp group rats were significantly elevatedwhile that of Gem and Ara grouPs we]ie reduced significantly at 8, l6week. However, there was no difference of serum Chol, LDL, HDL,creatinine and glucose level among ffhe four groups at the end ofexperiment.(2) UAE of Exp group was higher than Con grouP (P <0.05). While that ofother two groups intervened by lipid-lowing agents were lower than ExpgrouP obviously (P<0.05).(3) Pathological manifestation: In Exp g]roup, lipid deposited obviousIyamong tubular while less within gloineruli in slices stained by Oil red-O.Mesangial matrix expansion, celI prolif(:ration, and focal segmentaI evenglobal glomerulosclerosis could be observed in kidney. And segmentalepitheIium foot process fusion and cytoplasma detached could be seen underelectron microscopy A lit...
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