We compared the preservative effects of a monosaccharide (glucose), disaccharides (trehalose, maltose, sucrose), and a trisaccharide (raffinose) to investigate whether or not the effects of saccharides on lung preservation depend on their molecular weight, energy-level maintenance and cytoprotective effects. The effects of saccharides may depend on their cytoprotective effect rather than on impairment activity or energy-level maintenance of the preserved lung. Trehalose proved to be superior to the other saccharides.
Energy depletion closely correlates with ischemia-reperfusion (I-R) injury in solid organs, but there has been no conclusion about the lungs that contain air. We investigated the alveolar state during cold storage and its relation to energy metabolism and I-R injury in an ex-vivo rat lung model. The lung was deflated (DEF group) or inflated with either room air (RA group) or nitrogen (N2 group) for six hours at 4℃, and reperfused or bronchoalveolar lavage fluid (BALF) was c
ollected (N=6, each). Furthermore, the static lung compliance, the intrapulmonary levels of high energy phosphates, lactate and pyruvate were measured. The pulmonary functions of the DEF and N2 groups were significantly worse than those of the RA group. In the N2 group, the intrapulmonary levels of energy charge and pyruvate/lactate ratio were significantly lower than those in the DEF and RA groups, while there were no significant differences between the DEF and RA groups. In the DEF group, total protein and lactate dehydrogenase in the BALF were significantly higher while the static lung compliance was significantly lower compared with the N2 and RA groups. We concluded that aerobic metabolism would be essential for attenuating I-R injury of the lung, and inflation of the alveoli would be necessary for avoiding mechanical damage during re-expansion.