Effect of Warm Ischemia on Ultrastructure and Viability of Aortic Valve in Rats

Abstract

Warm ischemia is one of the most important causes of valvular damage between the time of the donor's death and the time of organ harvesting and cooling. We used qualitative and quantitative methods to characterize warm ischemic injury through models of SD rat aortic valves to demonstrate the relationship between ultrastructural viability and changes with warm ischemic time. Aortic valves were harvested from 102 SD rats and divided into 6 ischemic times for study. Additionally, 432 photomicrographs of transmission electron microscopy were analyzed. The volume ratio of nucleus to plasma in cells and the ratio of extra-membrane area to volume of mitochondria were used to characterize the degree of valvular cell injury. Valvular cell culture and biochemical metabolism, including glucose degradation and ³H-TdR absorption rates, were adopted. The viability of cultured cells and ³H-TdR uptake were also inhibited with prolonged warm ischemic time.