Respiratory Gas Tensions and Blood Flow in Wounds in Young and Old Rats

Abstract

In an attempt to understand the mechanism whereby the quality of granulation tissue formed in old animals is impaired, blood flow and respiratory gas tensions were studied in young and old rats, using subcutaneously implanted steel-wire-mesh cylinders as a wound model. The amount of tissue formed within the cylinders was the same in young and old rats. No significant differences were found between the groups as regards blood flow as calculated from the disappearance rate of Xenon^133. Oxygen tension was found to be higher and carbon dioxide tension and pH lower in wound fluid from old than from young rats. The observations indicate that in old animals the available oxygen is not utilized as effectively as in young animals.