An Experimental Model of the Krogh Tissue Cylinder: Two Dimensional Quantitation of the Oxygen Gradient

Abstract

We have observed very steep regional redox ratio transitions In Vivo in various tissues (1, 2, 3, 4). The most obvious example beeing the transition across the borderline of an ischemic area as first described by Barlow and Chance for an artificially produced infarct in a rat heart (5). We believe that the steep redox state transition may reflect similarly steep tissue oxygen gradients (6) and in order to probe that we have devised a simple model in which the ischemic borderzone in terms of oxygen gradient can be reproduced. The model is essentially a Krogh Tissue Cylinder (7) in macro scale, approximately 1:200, where the oxygen concentration profile perpendicular to the capillary may be recorded photographically in two dimensions. The model allows for independent variation of capillary oxygen tension, tissue oxygen consumption rate and facilitation of oxygen diffusion.