title: [Effect of C5-siRNA silencing receptor C5 on myocardial ischemia injury in rats].
abstract: OBJECTIVE
  To study the effect of C5-siRNA on pathological changes after myocardial ischemia in rats.
  
  
  METHODS
  Thirty healthy Sprague-Dawley rats were randomly divided into sham-operated group, ischemia group and C5-siRNA group. The cardiac ischemia models were established in ischemia group and C5-siRNA group by ligating the proximal end of the left anterior descending (LAD) coronary artery. The rats were infused with 100 microl/kg of C5-siRNA into myocardial tissue in C5-siRNA group and equal amount of normal saline in ischemia group and sham-operated group after ligating the LAD coronary artery for 30 min and then performed of ischemia for 4 hours. The cardiac index and left ventricular mass index were determined, morphological changes of myocardial tissue observed under optical microscope and the expression of C5 was detected by immunohistochemical staining and image analysis system.
  
  
  RESULTS
  There were no statistically significant difference between the three groups in the left ventricular mass index and cardiac index in the rats after ischemia for 4 hours. Light microscopy indicated edema and degeneration of the myocardial tissue were milder in C5-siRNA group than in ischemia group, a small amount of red blood cells existed in the myocardial stroma of the former. The expression of C5 was increased more significantly in ischemia group and C5-siRNA group than in sham-operated group (P<0.001), but was decreased in C5-siRNA group more than in ischemia group with no statistically significant difference between the two groups (P=0.132).
  
  
  CONCLUSIONS
  C5-siRNA could attenuate myocardial ischemia injury in rats by reducing inflammatory cell infiltration and expression of C5.
authors.affiliation: Department of Cardiovascular, Zhujiang Hospital, the Southern Medical University, Guangzhou 510282 China. jjx320@126.com
authors.forename: Ling-li
authors.initials: LL
authors.lastname: Cheng
authors.forename: Zhi-liang
authors.initials: ZL
authors.lastname: Li
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
authors.forename: Su-hua
authors.initials: SH
authors.lastname: Wu
authors.forename: Kai
authors.initials: K
authors.lastname: Tang
mesh_terms: D000818:Animals; D003182:Complement C5 / Q000235:genetics*; D008297:Male; D017202:Myocardial Ischemia / Q000235:genetics* / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D044087:Receptor, Anaphylatoxin C5a / Q000235:genetics*
chemical_list: D003182:Complement C5; D034741:RNA, Small Interfering; D044087:Receptor, Anaphylatoxin C5a