The Renal Protective Effects Of Tongxinluo Combined Jinlida On Diabetic Rats And Its Impact To The Akt/mTOR Signal Pathway

Objective: In this study, Sprague Dawley rats were induced to diabetesby high-sucrose-fat diet and a low dose of STZ by tail intravenous injection.The therapeutic effects of Tonxinluo combined Jinlida on DN and itsmechanism were observed to provide experimental evidence for the clinicalapplication of the theory of “treating DN from the collaterals”.Methods:80SPF Male SD rats were fed adaptively for1week and thenrandomly divided into Normal control group (N), Model group (M), Irbesartangroup (I), Tonxinluo group (T), Jinlida group (J) and Tonxinluo combinedJinlida group (TJ) according to the body weight. Rats in Normal control groupwere fed conventionally and the rats in the other5groups were fed withhigh-sucrose-fat diet during the experiment. Diabetes was induced after4weeks, all rats except that in N group were intravenous injected with STZ(35mg/kg) in tail, and the FBG were tested72hours later. Rats with FBG levelhigher than11.1mmol/L were considered diabetic and were used for the study.All the drugs were dissolved in5‰CMC solution to keep uniform suspension.Rats in M group were intragastric administrated with CMC for10ml·kg-1·d-1,and I group with Irbesartan for25mg·kg-1·d-1, T group with Tongxinluo for0.8g·kg-1·d-1, J group with Jinlida for1.5g·kg-1·d-1, TJ group were combinedwith the previous two drugs together. The drug delivery lasted for12weeks.The rats’ urine was collected to test microalbuminuria in the end, and all ratswere anesthetized with10%hydral after12hours’ fasting. Abdominal aorticblood was used to test the entire biochemical index. The left kidneys wereweighed and conserved in4%formaldehyde and2.5%glutaraldehyde forpathomorphology observation and immunohistochemistry test, and the rightkidneys were conserved in liquid nitrogen to detect the expression of Akt andmTOR that in the Akt/mTOR signal pathway. Results:1. General state of healthAll the diabetic rats showed significant polydipsia, polyphagia, polyuriaand emaciation. Several rats died during the experiments: one in N group,seven in M and TJ group, six in I, T and J group.2. Body weight, left kidney weight and relative kidney weightRats in M group had significant reduced body weight than that in Ngroup, with the significant larger left kidneys weight and relative kidneyweight (P＜0.01). Rats in the other administer groups were significantlyheavier than that in M group, and the relative kidney weight were significantlyreduced (P＜0.01).3. All the biochemical indexThere were significant differences in Blood Glucose, Lipid levels andkidney functions between M group and N group (P＜0.01). There were nosignificant differences in Blood Glucose and fructosamine between M groupand the other administer groups (P＞0.05). The levels of TC, TG and LDL inall administer groups were significantly reduced (P＜0.01), and the levels ofHDL in administer groups had varying increased degrees except that in Jgroup (P＜0.05, P＜0.01). The microalbuminuria in administer groups weresignificantly reduced than that in M group (P＜0.01), as well as the Scr andBUN (P＜0.05, P＜0.01).4. Changes of renal pathomorphologyThe tubular was obviously expanded in diabetic rats, and the epitheliumappeared diffuse vacuolar degeneration, but there were no visible pathologicalchanges in the glomeruli. The transmission electron microscope image showedfoot process fusion, enlarged endothelial fenestra and segmental thickenedglomerular basement membrane in diabetic rats, which were improved by drugadministration.5. The expression of VEGFThe expression of VEGF was significantly enhanced in diabetic rats’kidney, especially in the tubular epithelium, and the expression of VEGF in administer groups was weakened by different degrees.6. The expression of Akt and mTOR in Akt/mTOR signal pathwayThere were no statistical differences in Akt and mTOR between allgroups (P＞0.05), but the expression of Phosphorylated-Akt andPhosphorylated-mTOR in M group was significantly enhanced than that in Ngroup (P＜0.01), which means the activation of Akt/mTOR signal pathway.After all dugs treatment, the expression of Phosphorylated-Akt andPhosphorylated-mTOR were weakened (P＜0.01).Conclusion:1. Tongxinluo combined Jinlida had therapeutic effect to general state ofDN. The renal function of diabetic rats was improved by Tongxinluocombined Jinlida, which could reduce the early microalbuminuria, regulateblood lipids levels and improve the general condition of diabetic mellitus.2. Tongxinluo combined Jinlida could suppress the Akt/mTOR signalpathway and the expression of VEGF, which may be one of the mechanismsfor the treatment of DN.3. The renal pathological changes of diabetic rats could be extenuated byTongxinluo combined Jinlida, and the progression of diabetic nephropathywas delayed.