Effects of inosine on reperfusion injury after cardiopulmonary bypass.
OBJECTIVE
Inosine, a break-down product of adenosine has been recently shown to exert inodilatory and anti-inflammatory properties. Furthermore inosine might be a key substrate of pharmacological post-conditioning. In the present pre-clinical study, we investigated the effects of inosine on cardiac function during reperfusion in an experimental model of cardioplegic arrest and extracorporal circulation.


METHODS
Twelve anesthetized dogs underwent hypothermic cardiopulmonary bypass. After 60 minutes of hypothermic cardiac arrest, reperfusion was started after application of either saline vehicle (control, n = 6), or inosine (100 mg/kg, n = 6). Left ventricular end-systolic pressure volume relationship (ESPVR) was measured by a combined pressure-volume-conductance catheter at baseline and after 60 minutes of reperfusion. Left anterior descendent coronary blood flow (CBF), endothelium-dependent vasodilatation to acetylcholine (ACh) and endothelium-independent vasodilatation to sodium nitroprusside (SNP) were also determined.


RESULTS
The administration of inosine led to a significantly better recovery (given as percent of baseline) of ESPVR 90 ± 9% vs. 46 ± 6%, p < 0.05. CBF and was also significantly higher in the inosine group (56 ± 8 vs. 23 ± 4, ml/min, p < 0.05). While the vasodilatatory response to SNP was similar in both groups, ACh resulted in a significantly higher increase in CBF (58 ± 6% vs. 25 ± 5%, p < 0.05) in the inosine group.


CONCLUSIONS
Application of inosine improves myocardial and endothelial function after cardiopulmonary bypass with hypothermic cardiac arrest.
Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany. gaborveres@yahoo.com
Gábor
G
Veres
Tamás
T
Radovits
Leila
L
Seres
Ferenc
F
Horkay
Matthias
M
Karck
Gábor
G
Szabó
D000818:Animals; D002302:Cardiac Output / Q000187:drug effects; D002315:Cardiopulmonary Bypass; D003326:Coronary Circulation / Q000187:drug effects; D004285:Dogs; D006324:Heart Arrest, Induced; D007288:Inosine / Q000627:therapeutic use*; D009200:Myocardial Contraction / Q000187:drug effects; D015428:Myocardial Reperfusion Injury / Q000503:physiopathology* / Q000517:prevention & control; D013318:Stroke Volume / Q000187:drug effects; D016276:Ventricular Function / Q000187:drug effects; D017725:Ventricular Pressure / Q000187:drug effects
D007288:Inosine