The Relationship Between Mycardial Infarct Size And The Overexpression Of Micrornas-21

Objective：To investigate the effects on myocardial infarction size through theoverexpression of micrornas-21after myocardial infarction in mice.Methods:40healthy male standard Sprague Dawley rats weighing250-300g wereused and anesthesiaed by intraperitoneal injection of urethane(25%). randomlydivided into four groups, each group of10, respectively is: the group of carryingmicrornas-21gene adenovirus vectors, the group of adenovirus vector with no gene,saline group and sham group. under relatively aseptic conditions, myocardialinfarction(MI) was produced by ligation of anterior descending coronary artery, thesham group underwent the same procedure without coronary artery ligation. After themodel of myocardial infarction is established by observing the ECG ST segmentelevation for30minutes and distal myocardial turning to pale. then infuse Ad-MiR-21gene adenovirus virus vectors, adenovirus vector with no gene, saline equivalentdose100ul（virus titer is1.0×109pfu for every rat）respectively using micro syringeinjection. close chest after intraperitoneal injection of400000units penicillin toprevent infection, continue to feed rats for3days, dislocate rats after three days, takeout the heart,flush the heart by saline, frozen section by TTC staining to detectmyocardial infarction size; PCR detection of myocardial infarction, the surroundingtissue micrornas-21gene expression, then statistical processing of the data, draw theconclusion.Results: The expression of micrornas-21of injection with microras-21adenovirusvector group was significantly increased than than that among the other threegroups(P<0.01).There was no obvious difference among the other three groups; Myocardial infarction size of micrornas-21adenovirus vector group also wassignificantly decreased than the other groups (P<0.05).There was no significantstatistical differences among the other three groups.Conclusion: Intramyocardial injections by directly injection with mirna-21geneadenovirus vectors can realize overexpression of microRNA-21gene, the geneexpression of micrornas-21in three days after myocardial infarction has the effectthat reduce myocardial infarct size, the specific mechanism remains to be furtherstudy.