Heat shock proteins, end effectors of myocardium ischemic preconditioning?
The purpose of this study was to investigate (1) whether ischemia-reperfusion increased the content of heat shock protein 72 (Hsp72) transcripts and (2) whether myocardial content of Hsp72 is increased by ischemic preconditioning so that they can be considered as end effectors of preconditioning. Twelve male minipigs (8 protocol, 4 sham) were used, with the following ischemic preconditioning protocol: 3 ischemia and reperfusion 5-minute alternative cycles and last reperfusion cycle of 3 hours. Initial and final transmural biopsies (both in healthy and ischemic areas) were taken in all animals. Heat shock protein 72 messenger ribonucleic acid (mRNA) expression was measured by a semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method using complementary DNA normalized against the housekeeping gene cyclophilin. The identification of heat shock protein 72 was performed by immunoblot. In our "classic" preconditioning model, we found no changes in mRNA hsp72 levels or heat shock protein 72 content in the myocardium after 3 hours of reperfusion. Our experimental model is valid and the experimental techniques are appropriate, but the induction of heat shock proteins 72 as end effectors of cardioprotection in ischemic preconditioning does not occur in the first hours after ischemia, but probably at least 24 hours after it, in the so-called "second protection window."
Guisasola
María Concepcion
MC
Unit of Experimental Medicine and Surgery, Hospital General Universitario Gregorio Marañon, 28007 Madrid, Spain. hsp@mce.hggm.es
Desco
Maria del Mar
Mdel M
Gonzalez
Fernanda Silvana
FS
Asensio
Fernando
F
Dulin
Elena
E
Suarez
Antonio
A
Garcia Barreno
Pedro
P
D000818:Animals; D050884:HSP72 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D019194:Ischemic Preconditioning; D007700:Kinetics; D008297:Male; D017202:Myocardial Ischemia / Q000378:metabolism* / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000473:pathology; D009206:Myocardium / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D015203:Reproducibility of Results; D013552:Swine; D013556:Swine, Miniature; D014741:Video Recording
D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D012333:RNA, Messenger