Immunohistochemical localization of alpha 1-antitrypsin in normal mouse liver and pancreas.

Using horseradish peroxidase and fluorescence immunohistochemistry, alpha 1-antitrypsin (alpha 1AT) was demonstrated in normal mouse hepatocytes and pancreatic islet cells. All hepatocytes were positive; 1--3% stained intensely for alpha 1AT. These were located mainly in the periportal area as well as randomly distributed, both singly and in clusters, throughout the liver lobule. Nonparenchymal liver cells were negative for alpha 1AT. The type of hepatocyte cytoplasmic staining appears to after during ontogeny, changing from a localized granular to a diffuse pattern. The use of immunohistochemistry to demonstrate alpha 1AT in normal mouse liver allows us to examine the acute phase response at a cellular level.