Synthesis of alpha 2-macroglobulin in human gingiva: a study of the concentration of macroglobulin and albumin in gingival fluid and serum.

Albumin and alpha 2-macroglobulin were analysed in gingival fluid collected by filter paper strips from 6 volunteers before, during and after 10 days of dental plaque accumulation. The two proteins were also determined in samples of venous blood at the beginning of abstention from tooth brushing and 10 days later. A nephelometric technique was used for the analysis of albumin, but alpha 2-macroglobulin was determined by ELISA. The plaque and gingival indices, as well as the flow of gingival fluid, increased significantly during the period of plaque accumulation and then returned to baseline values. The concentrations of the two proteins in blood remained within normal limits. In gingival fluid, however, the concentration of albumin increased about two-fold at the peak of inflammation, while that of alpha 2-macroglobulin increased as much as 6 times. The enhanced passage of alpha 2-macroglobulin into the gingival sulcus in comparison to the entirely plasma-derived albumin was consistent with the concept that the greater excretion of globulin during inflammation must be due to an increased local synthesis.