The demonstration of alpha 1 antitrypsin in periapical lesions.

Discontinuous vertical gel electrophoresis was applied to samples of root canal aspirate, periapical blood, and control blood from twelve periapical lesions. The periapical sample from ten of the twelve lesions showed an additional band in the alpha 1 globulin area which was not present in the control. By means of Grabbar-Williams immunoelectrophoresis to specific antisera, the band was subsequently identified as alpha 1 antitrypsin. The results suggest that the regulation of proteolytic activity afforded by alpha 1 antitrypsin plays an important role in the pathogenesis of periapical lesions.