Patterns of aortic evans blue uptake in vivo and in vitro

Abstract

Patterns of aortic uptake of the protein-binding azo dye, Evans blue, have been studied both in vitro and in vivo in young (8–12 week) and older (6 month) pigs. In vitro patterns of blueing were independent of the composition of the various incubation media employed, and were similar for young and older animals. Dye uptake patterns in vivo were likewise similar for young and older pigs, but differed markedly from the patterns observed in vitro. Altered tissue viability did not appear to account for the observed in vivo and in vitro differences. It is likely that hemodynamic factors determine the focal patterns of dye uptake in vivo. The factor or factors responsible for the in vitro dye uptake pattern remain uncertain, and injury occurring during aortic removal cannot be excluded. These studies have shown that the characteristic in vivo pattern of aortic Evans blue uptake is not reproduced in vitro, and for this reason, further characterization of the structural and metabolic features of areas of Evans blue uptake will necessitate the use of the in vivo blueing model.