Different susceptibility of cortical and medullary rat kidney mitochondria to ischemic injury.

Rat kidneys were exposed for different times to in vitro ischemia at 37 degrees C. Then the mitochondria of cortex and medulla were isolated and their respiratory qualities were determined. In dependence on the ischemic time, the active respiration (state 3) and the respiratory control index decreased whereas the resting state respiration (state 4) increased. The cortical mitochondria were affected more strongly by ischemia than medullary mitochondria. Therefore, the different susceptibility of cortical and medullary mitochondria to ischemia does not explain the suggested high risk of medulla for ischemia.