EFFECTS OF ISCHEMIA AND PRESERVATION ON THE ULTRASTRUCTURE OF THE BRONCHIOLAR EPITHELIUM - A QUANTITATIVE ELECTRON-MICROSCOPIC STUDY OF HUMAN AND CANINE LUNGS

In ten cases of clinical human single-lung transplantation, the nontra nsplanted Euro-Collins-preserved contralateral lungs were examined usi ng electron microscopy to determine the effects of ischaemia on the br onchiolar epithelium. Existing structural dam age at the time of trans plantation was characterized using this approach, and nine nonpreserve d canine single lungs were also investigated to identify the impact of ischaemia. The study revealed a significant correlation between the d uration of ischaemia and the mitochondrial surface-to-volume ratio, wh ich can serve as a morphometric criterion for mitochondrial damage, in canine lungs. However, this correlation was not found in the human do nor lungs, Further examination of human donor lungs showed slight to m oderate damage to the endoplasmic reticulum and nuclear chromatin. In addition, various degrees of damage to mitochondrial structure, rangin g from inconspicuous to severe, were found. The mitochondrial surface- to-volume ratio can be considered to be a suitable criterion for the q uantification of ischaemic damage of the bronchiolar epithelium under experimental conditions. Ultrastructural analysis of human donor lungs revealed intact bronchiolar epithelial cell structures at the time of transplantation, reflecting adequate organ preservation with Euro-Col lins solution.