ABSTRACT
Objective To investigate the protective effects of astragaloside IV (AS IV) on chronic intermittent hypoxia (CIH) -induced cardiac injury. Methods Twenty-four male adult Sprague Dawley rats were randomly assigned to control, CIH, CIH+ASIV, and ASIV group, 6 rats in each group. Circular nitrogen and oxygen were filled to make oxygen concentration change between 9%-21% for the CIH treated rats. The exposure cycle was repeated every 3 minutes, 8 hours/ day for 35 days. ASIV was given by intragastric administration daily before intermittent hypoxia exposure in the CIH+ASIV group and AS IV group. The control group and CIH group were given normal saline of the same quantity. Echocardiography was used to analyse cardiac function. Myocardial structure was assessed by HE and wheat germ agglutinin staining. The apoptosis of cardiomyocytes was detected by TUNEL assay. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in heart were detected by commercial kits. Western blotting was used to evaluate the levels of Bcl-2, Bax, LC3, Beclinl, P62, and mammalian target of rapamycin (mTOR). Results In the CIH group, the left ventricular ejection fraction (LVEF) and left ventricular internal diameter at end-systole (LVIDs) were inhibited, the myocyte cells showed disordered arranged, enlarged diameters and higher apoptosis rate. The MDA content was significantly elevated and the SOD activity decreased in CIH group when compared with those of control. What's more, the expression level of Beclin 1 decreased while the P62 expression and the p-mTOR/mTOR ratio increased in the CIH group. Compared with the model group, the LVEF, LVIDs, SOD activity, LC3 H / I ratio, and Beclinl expression of rats in the CIH + AS IV group increased. The cardiomyocytes in the rats of CIH + ASIV group showed normal arrangement and diameters. The apoptosis rate, MDA content, P62 expression and the p-mTOR/mTOR ratio decreased in the CIH+ASIV group when compared with the CIH group. Conclusion AS IV can alleviate CIH-induced cardiac injury by promoting autophagy via mTOR.
ABSTRACT
BackgroundPterygia is a clinical common disease.A lot of surgical methods are developed to decrease the recurrence rate.Resent years,the application of fibrin glue is receiving more and more attention.Objective This study was to explore the effects of fibrin glue in decreasing inflammatory irritation and its mechanism. Methods Pterygia models were created in 12 clean rabbits by exsection of limbal tissue and topical administration of 1.25％ diluted hydrochloric acid,and then the conjunctival autograft surgery was performed in the experimental rabbits.The conjunctival flap was sutured in the left eyes,and the conjunctival wound was closed using fibrin glue in the right eyes.The operation duration for each group was documented and compared.The irritation sign was examined under the slit lamp in all the rabbits 1 week and 4 weeks respectively.The expressions of vascular endothelial growth factor (VFGF) and basic fibroblast growth factor (bFGF) proteins in the conjunctiva tissue were detected by immunochemistry,and the expressions of VFGF mRNA and bFGF mRNA in the conjunctival tissue were determined by reverse transcription polymerase chain reaction (RT-PCR).Results The operative duration was (21.3±0.2) minutes in suture group and( 10.1 ±0.1 )minutes in the fibrin glue group with a significant difference between two groups( t =102.242,P＜0.05 ).From 1 week through 4 weeks,the hyperemiain degree was obviously slight in fibrin glue group compared with suture group.Immunochemistry showed that VEGF and bFGF proteins were expressed mainly in the cytoplasm of conjunctival epithelium layer.The positive response intensity was weaker in the fibrin glue group than in suture group 1 week and 4 weeks after operation.RT-PCR revealed that the expression level of VEGF mRNA was significantly lower in fibrin glue group than in suture group,and the VEGF mRNA was gradually decreased with the time lapse ( Fgroup =174.443,P =0.000 ; Ftime =231.459,P =0.000 ).The similar outcomes were found in the expression of bFGF mRNA(Fgroup=41.727,P=0.000;Ftime=55.417,P=0.000). ConclusionsThe use of fibringluecanshortentheoperationdurationandreducepostoperationinflammatoryreaction.The downregulation of VEGF and bFGF in tissue is the possible mechanism of remitting irritation sign,which allows a reduce of the recurrence rate of pterygia.