The Micro Pathological Features Of Traditional Chinese Medicine In Rats Model Of ’Decrease Of Tertiary Collaterals’ Of Collateral Disease

Objective:The application of coronary microvascular ischemia model is used toinvestigate the relationship between pathological changes of coronary microvascularischemia and ‘decrease of tertiary collaterals’of collateral disease. Methods:A total of240male Sprague-Dawley rats with regular ECG performance were randomly dividedinto a Sham group, a30min-group, a1h-group, a6h-group, a12h-group and a24h-group. The model of ‘decrease of tertiary collaterals’ of collateral disease in heartwas established after ligation of the left anterior descending coronary artery, while thesham group was threaded without ligation. After the modeling,Each group is served fordetetion at the time setted.ECG detetion and TTC staining;Changes of Myocardial bloodflow in the surface of heart is acquired by the techniques of microcirculation livingobservation;The level of plasma ET-1,TXB2,6-Keto-PGFla, AngⅡ,NO and VEGF weredetected with radioimmunoassay;The changes of pathological in myocardium wereobserved by HE staining，and the changes of ultra microstructure in myocardium weredetected by transmission elec-tron microscope;Immunohistochemical detection ofMVD、VEGF、Bcl-2、Bax and TUNEL staining;The iNOSmRNA、ET-1mRNA、ICAM-1mRNA、VCAM-1mRNA are detected by qPCR.Results:1.ECG changes:At the beginning of modeling the ST segment elevatedprogressively,this elevation gradually fall over time.Actually, the ST segmentperformance of most model rats went back to normal base line. Pathologic Q wavesconstantly stay in ECG. Arrhythmia could be occasionally seen,such as atrioventricularblock, premature ventricular contractions.2.TTC staining: Rats of30min-group and1h-group showed a whole red staining ofheart. Rats of6h-group,12h-group and24h-group showed a white staining in theposition of left ventricular apical and septal. 3. Surface myocardial blood flow:The myocardial blood flow in the surface ofheart descending as soon as the model is completed(P<0.01). While12h-group has moreblood flow than the previous group,still lower than the Control group.Finally,24h groupshowed the same as the control group.4. Myocardial histopathology and ultra structure changes: HE staining,inflammatory cell infiltration and partial myocardial necrosis contribute to the mainpathologic changes in the group of30min and1h.While,the obvious change ofinflammatory cell infiltration happens in6h,accompanied by myocardial necrosis. Atthe time of12h and24h, Proliferative changes became the major changes.Besides,therewas no obvious changes of inflammatory cell infiltration at24h. Under the transmissionelectron microscopy,lots of ultra microstructure changes， Z lines,M lines andintercalated discs blured in all of the model group，so was the change of mitochondrialswelling.The following changes are Myocardial cell edema and Myofibrillar focaldissolution.The further changes are myocardial necrosis and interstitial vascularendothelial cell apoptosis.The most severe changes happen at12h.5. Vasomotor factor changes of blood plasma: Compared with the sham group,theET-1level in the1h-group, the6h-group and the12h-group was significantlyincreased(P<0.05), then returned to normal at24h. The TXB2level was obviouslyincreased in the6h-group(P<0.01), while decreased apparently at the12h-group and the24h-group (P<0.05). The6-keto-PGFlα level in all the model groups was significantlydecreased (P<0.01or P＜0.05), then reached the low peak at12h. The AngⅡ level inthe30min-group and the1h-group was obviously decreased (P<0.01or P＜0.05), thenreached the low peak at1h, while it returned to normal in the6h-group, the12h-groupand the24h-group.6.Expresion of newborn and apoptosis protein changes: VEGF and CD34of modelgroups express obviously increased than control group（P＜0.01）; The number ofpositive apoptotic cells of TUNEL in model groups is higher than control group（P＜0.01）; Bcl-2and Bax of model groups expression are obviously more than controlgroup（P＜0.01）. 7.Expression changes of vasomotor mRNA: Expression of iNOSmRNA issignificantly increased in model groups of1h,6h,12h and24h（P＜0.01or P＜0.05）;Expression of ET-1mRNA obviously increased in model groups of12h and24h（P＜0.01）; Expression of iCAM-1mRNA is obviously elevated in model groups of6h,12hand24h（P＜0.01）.Besides, non-infracted area has an early expression than infarct zone;Expression of VCAM-1mRNA is obviously elevated in model groups of1h,6h,12h and24h（P＜0.01）.What’s more, non-infracted area has an obviously early expression thaninfarct zone.Conclusions:1. The method of "ligation of the left anterior descending coronary artery" cansuccessfully established the model of ‘decrease of tertiary collaterals’ of collateraldisease in heart.2.In the condition of ‘decrease of tertiary collaterals’, tertiary collaterals declinedin terms of quantity and function, function can be partly recovered spontaneously.3. Deficiency of qi-xue resulting from ‘decrease of tertiary collaterals’ lead tomany myocardial pathological changes, including inflammatory infiltration, fiberbreakage and solution, myocardial edema and necrosis, endothelial cell necrosis.4. Interaction of micro vascular disorder and micro vascular vasomotor factorimbalance, together with inflammation, oxidative stress and platelet dysfunction,contribute the most to the damage of ‘decrease of tertiary collaterals’.5.Expression of apoptotic proteins is an important sign of myocardial necrosis,while newborn proteins serve as compensatory regulation to make a protectablefunction.