Morphological and functional recovery of the canine gallbladder mucosa following two hours' ischemia

Temporary interruption of the circulation to the canine gallbladder causes hemorrhagic necrosis of the mucosa and an abolition of active transport of glycine in vitro. The first signs of epithelial recovery following two hours' ischemia are seen in animals examined 7 days after the injury and are characterized by the appearance of a layer of cuboidal epithelial cells in which some mitotic figures are observed, accompanied by a decrease in the amount of necrosis and the presence of granulation tissue. At the same time, there is some slight resumption in glycine uptake. Two weeks after injury, the new epithelium covers a larger surface of the gallbladder wall but recovery is still incomplete. Four weeks after operation, structural and functional recovery has occurred in almost all the animals studied: the epithelium is columnar and does not differ greatly from that seen in the normal gallbladder. Mucosal folds are present although their morphological appearance is slightly altered in comparison with those of control specimens. The gallbladder wall is thickened by fibrosis. Measurements of active glycine transport in vitro confirm that the new epithelium functions normally.