Comparison on Rat Models of Acute Cerebral Infarction Due to Stasis Combined with Toxin Complicated with Cerebral-cardiac Syndrome / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo observe and compare the electrocardiogram index， myocardial morphology， and connexin 43 （Cx43） expression of two rat models of acute cerebral infarction （ACI） due to stasis combined with toxin complicated with cerebral-cardiac syndrome （CCS）， and to provide experimental evidence for the research on the occurrence mechanism of cardiac diseases induced by ACI and the clinical diagnosis and treatment of CCS. MethodSixty SPF-grade male SD rats were randomized into six groups （n=10）： normal ， syndrome of stasis combined with toxin induced by carrageenin combined with dry yeast （CA/Y）， multi-infarct induced by micro-embolism （ME）， middle cerebral artery occlusion （MCAO）， CA/Y+ME， and CA/Y+MCAO groups. The model of syndrome of stasis combined with toxin was established by intraperitoneal injection with carrageenan （CA） at 10 mg·kg-1 on the first day and subcutaneous injection with dry yeast （Y） suspension （2 mg·kg-1） on the second day of modeling. Twenty-four hours after the modeling of ACI， the electrocardiograms （ECGs） of rats in each group were collected and the number/percentage （%） of abnormal ECG was calculated. The infarct area of the brain was evaluated by 2，3，5-triphenyltetrazolium chloride （TTC） staining， and myocardial injury was assessed by hematoxylin-eosin （HE） staining. Immumohistochemical staining and Western blot were employed to determine the expression of Cx43 in the myocardium. ResultA certain number of rats in each model group presented abnormal ECG. Compared with the normal group and CA/Y group， CA/Y+MCAO group had the highest rate of abnormal ECG （P<0.01）. Compared with the normal， CA/Y， ME， and CA/Y+ME groups， the CA/Y+ME and CA/Y+MCAO groups showed decreased amplitudes of P-wave and T-wave， shortened P-R interval， and extended Q-T interval， which were particularly obvious in the CA/Y+MCAO group （P<0.05， P<0.01） and in accordance with the cerebral infarction area and pathological changes. The expression of Cx43 was up-regulated in both CA/Y+ME and CA/Y+MCAO groups， especially in the CA/Y+MCAO group （P<0.01）. ConclusionThe two rat models of ACI due to stasis combined with toxin complicated with CCS can be used to study the mechanism of heart diseases caused by cerebrovascular diseases and the therapeutic effects of Chinese medicines with the functions of resolving stasis and detoxifying. Moreover， the CA/Y+MCAO method has higher abnormal electrocardiogram rate， severer myocardial pathological injury， and higher expression of Cx43 protein. The models can be chosen according to specific experimental purpose.