The rabbit ear containing a mature Lucite chamber was subjected to
ischemia in 25 rabbits. The ischemic insult lasted in one group for 2 hours, in the second group for 5 hours, and in a third group for 5 hours with the addition of systemic
prednisolone therapy. The gross
edema of the ear, restoration of flow within the microvasculature in the rabbit ear chamber, and the occurrence and resolution of the cellular inflammatory response were documented by daily in vivo observations of the chamber. The 2-hour ischemic period resulted in a relatively insignificant injury, but the 5-hour ischemic period resulted in
edema of the ear, changes in the flow within the microvasculature, and a cellular inflammatory response that increased in intensity for the first 24 hours following
ischemia. Ultimate resolution of these changes was noted in all the animals. Systemic administration of
prednisolone dramatically reduced the occurrence of
edema and reduced the intensity of the inflammatory response, which resolved in a shorter period of time than in untreated animals. These studies demonstrate that
ischemia evokes a classic inflammatory response that is inhibited by the administration of systemic
steroids.