When does the lung die? K-fc, cell viability, and adenine nucleotide changes in the circulation-arrested rat lung

Lungs harvested from cadaveric circulation-arrested donors may increase the donor pool for lung transplantation. To determine the degree and time course of ischemia-reperfusion injury, we evaluated the effect of O-2 ventilation on capillary permeability [capillary filtration coefficient (K-fc)], cell viability, and total adenine nucleotide (TAN) levels in in situ circulation-arrested rat lungs. K-fc increased with increasing postmortem ischemic time (r = 0.88). Lungs ventilated with O-2 1 h postmortem had similar K-fc and wet-to-dry ratios as controls. Nonventilated lungs had three-fold (P < 0.05) and sevenfold (P < 0.0001) increases in K-fc at 30 and 60 min postmortem compared with controls. Cell viability decreased in all groups except for 30-min postmortem O-2-ventilated lungs. TAN levels decreased with increasing ischemic time, particularly in nonventilated lungs. Loss of adenine nucleotides correlated with increasing K-fc values (r = 0.76). This study indicates that lungs retrieved 1 h postmortem may have normal K-fc with preharvest O-2 ventilation. The relationship between K-fc and TAN suggests that vascular permeability may be related to lung TAN levels.