Uridine-5'-triphosphate (UTP) reduces infarct size and improves rat heart function after myocardial infarct.
We have previously found that uridine 5'-triphosphate (UTP) significantly reduced cardiomyocyte death induced by hypoxia via activating P2Y(2) receptors. To explore the effect of UTP following myocardial infarction (MI) in vivo we studied four groups: sham with or without LAD ligation, injected with UTP (0.44microg/kg i.v.) 30min before MI, and UTP injection (4.4microg/kg i.v.) 24h prior to MI. Left ventricular end diastolic area (LVEDA), end systolic area (LVESA) fractional shortening (FS), and changes in posterior wall (PW) thickness were performed by echocardiography before and 24h after MI. In addition, we measured different biochemical markers of damage and infarct size using Evans blue and TTC staining. The increase in LVEDA and LVESA of the treated animals was significantly smaller when compared to the MI rats (p<0.01). Concomitantly, FS was higher in groups pretreated with UTP 30min or 24h (56+/-14.3 and 36.7+/-8.2%, p<0.01, respectively). Ratio of infarct size to area at risk was smaller in the UTP pretreated hearts than MI rats (22.9+/-6.6, 23.1+/-9.1%, versus 45.4+/-7.6%, respectively, p<0.001). Troponin T and ATP measurements, demonstrated reduced myocardial damage. Using Rhod-2-AM loaded cardiomyocytes, we found that UTP reduced mitochondrial calcium levels following hypoxia. In conclusion, early or late UTP preconditioning is effective, demonstrating reduced infarct size and superior myocardial function. The resulting cardioprotection following UTP treatment post ischemia demonstrates a reduction in mitochondrial calcium overload, which can explain the beneficial effect of UTP.
Yitzhaki
Smadar
S
The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel.
Shainberg
Asher
A
Cheporko
Yelena
Y
Vidne
Bernardo A
BA
Sagie
Alex
A
Jacobson
Kenneth A
KA
Hochhauser
Edith
E
D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D002316:Cardiotonic Agents / Q000494:pharmacology; D002478:Cells, Cultured; D003402:Creatine Kinase / Q000097:blood; D004452:Echocardiography; D006321:Heart / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects; D000860:Hypoxia / Q000378:metabolism; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D020107:Troponin T / Q000097:blood; D014544:Uridine Triphosphate / Q000494:pharmacology*
D002316:Cardiotonic Agents; D020107:Troponin T; D000255:Adenosine Triphosphate; D003402:Creatine Kinase; D002118:Calcium; D014544:Uridine Triphosphate