Proceedings of The Physiological Society
University of Bristol (2005) J Physiol 567P, C71
Pre-arrest administration of cell permeable ROS scavenger, Tempol, reduces warm ischaemic damage of lung function in non-heart-beating donors
Hodyc, Daniel; Hnilickova, Olga; Hampl, Vaclav; Herget, Jan;
1. Physiology, 2nd Medical School, Charles University, Prague, and Centre for Cardiovascular Research, Prague, Czech Republic.
To use lungs retrieved from non-heart-beating donors (NHBD) in a safe way it is necessary to design an optimal method of their preservation during warm ischaemia. One of the most deteriorative effects of warm ischaemia is caused by ROS activity. Therefore we investigated a possible protective effect of cell permeable ROS scavenger, Tempol, on the function of NHBD grafts. Four groups (n = 6) of Wistar male rats underwent experimental protocol of lung harvesting from NHBD. After pre-arrest administration of heparin, rats were humanely killed by an overdose of sodium pentobarbitone and then left untouched for 60 min (warm ischaemia) followed by 90 min of cold ischaemia provided by intrapleural in situ topical cooling. Group I: non-ventilated during warm ischaemia, group II: non-ventilated, Tempol (100mg/kg b.w.) added pre-arrestly intraperitonealy, group III: room-air ventilated, group IV: room-air ventilated, Tempol. Controls were: group V (n = 6) and group VI (n = 6) with Tempol added, in both lungs harvested immediately under anaesthesia by sodium thiopental (50mg/kg added intraperitonealy) without warm and cold ischaemia. For functional assessment of all groups we used preparation of isolated ventilated rat lungs perfused with salt solution with Ficoll (4g/100ml) and meclofenamate (17 x 10exp-6 M). Perfusion pressure, lung weight gain and arterio-venous difference in oxygen partial pressure (dPO2) were measured in time periods of 30, 90 120 and 180 min after beginning of perfusion. To model in vivo conditions for oxygen transport, the perfusate was equilibrated with hypoxic gas mixture before entering the preparation. For statistical evaluation we used ANOVA for repeated measures, Games/Howell post hoc test, p<0.05. We did not find any differences between controls (group V and VI). Almost all lungs (5 of 6) retrieved from room-air ventilated rats without Tempol (group III) developed pulmonary oedema by 30 min of isolated lung perfusion, in contrast to 100% survival in all other groups. There were no differences in perfusion pressure between these groups. We found significant increase in weight gain in non-ventilated lungs (group I) compared with non-ventilated with Tempol (group II) or room-air ventilated with Tempol (group IV) - see Fig. 1. dPO2 was significantly lower in non-ventilated lungs (group I) than in controls (group V); in contrast, there were no differences in oxygen transport ability between non-ventilated, room-air ventilated and control groups with Tempol - see Fig. 2. Pre-arrest administration of Tempol helps in protection of lung grafts retrieved from NHBD.
Where applicable, experiments conform with Society ethical requirements