Abstract
The early development of post-ischemic cell injury was investigated in rat livers. Rats were subjected to 90 minutes of liver ischemia, followed by periods of re-perfusion from 10 minutes to 3 hours. The ischemia-induced injury was quantified by using a double staining method. An intravital dye exclusion test with Evans blue was combined with a histochemical stain for calcium, Alizarin red S (ARS). It was found that the markers identified two populations of injured cells, positive for Evans blue (EBA) and ARS respectively. The number of injured cells increased successively during the re-perfusion period. The overlapping between the two populations was small during the early post-ischemic phase but increased with increasing re-perfusion time. Treatment with ruthenium red, a blocker of mitochondrial calcium uptake, during the re-perfusion period significantly reduced the number of ARS-positive cells, while the number of EBA-positive cells was not affected. It is suggested that the two markers used identify cell populations, which are injured by different mechanisms operating in the post-ischemic phase. These mechanisms may or may not be dependent on calcium.