Expression of tissue transglutaminase in blood and lymphatic vessel endothelia and in mesothelium.

This study was undertaken to evaluate tissue transglutaminase (TG2) expression in guinea pig tissues, using an antibody against the guinea pig liver TG2. The tests were performed by means of a few immunohistochemical methods in specimens from: gut, skin, the lungs, lymph nodes, the heart, the thymus, the spleen, skeletal muscles of control guinea pigs and from inflamed skeletal muscles and skin. TG2 expression was found in artery, vein and lymphatic vessel endothelia, in mesothelia of pleura, pericardium and peritoneum, and in smooth muscle cells. Spleen deserves a special attention, since this organ, especially rich in TG2, may be much more involved in celiac disease and in liver diseases than it has been accepted so far. The subject calls for further elucidation.