| Autor: |
Denis Simard, John G. Kingma, Jacques R. Rouleau, Mette Hazenberg |
| Rok vydání: |
1995 |
| Předmět: |
|
| Zdroj: |
Journal of the American College of Cardiology. 25:43A |
| ISSN: |
0735-1097 |
| DOI: |
10.1016/0735-1097(95)91633-9 |
| Popis: |
The anti-infarct effect of ischemic preconditioning (PC) is partly due to adenosine receptor-mediated opening of KATPchannels. PC-mediated protection may be potentiated by exogenous infusion of adenosine receptor agonists. To test this hypothesis, pentobarbital anesthetized rabbits (n = 8/group) underwent two cycles of 5 min regional ischemia and 5 min coronary reperfusion (REP; i.e., PC) followed by 30 min ischemia and 3 h REP. Rabbits received either adenosine (AD; 0.01 mg/min); cyclopentyladenosine (CP; A1receptor agonist; 0.001 mg/min) or CGS 21680 (CG; A2receptor agonist; 001 mg/min), i.v.for 65 min starting 5 min before onset of REP. KATPchannels were blocked with i.v.glibenclamide (G; 0.15 mg/kg) 10 min before PC in the absence or presence of AD, CP or CG. Infarct and risk (R; cm3) volume was assessed with tetrazolium and microsphere autoradiography. Infarct size (IS) was normalized to R. IS in absolute controls (i.e., no PC) was 51 ± 6% (mean ± SEM). PC G + PC AD G + AD CP G + CP CG G + CG R 1.6 ± 1 1.8 ± 0.2 1.6 ± 0.2 1.4 ± 0.1 1.9 ± 0.1 1.4 ± 0.3 2.0 ± 0.2 1.2 ± 0.1 IS 19 ± 2 39 ± 7† 27 ± 7 37 ± 6† 12 ± 1† 44 ± 9† 22 ± 3 50 ± 5† † P ≤ 0.05: one-way ANOVA and SNK multiple range test Full-size table Table options View in workspace Download as CSV Cardiodynamics were similar for the treatment groups; but heart rate-blood pressure product was lower (p ≤ 0.05) during CP infusion. Conclusions PC markedly reduced IS; 2) PC-mediated protection was not potentiated with exogenous AD, CP or CG; and 3) G abolished PC-mediated protection without/with exogenous AD, CP or CG. These data indicate that adenosine receptor activation and opening of KATPchannels are involved in PC. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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