Nonspecific esterases of epithelioid granulomas were studied histochemically in developing and healing lesions produced in rabbit lung by BCG or Freund's complete adjuvant. Nonspecific esterases were assayed with the following substrates: acid α-naphthyl acetate (acid α-N), α-naphthyl acetate (α-N), naphthol AS-D chloroacetate (AS-D Chl), naphthol AS acetate (AS), and naphthol AS-D acetate (AS-D).
The nonspecific esterases in the epithelioid cells of two types of granulomas could be classified into two groups on account of the chronologic change of enzyme activity. In the first group including acid α-N esterase, the activities were prominent through all stages of the granuloma. On the other hand, in the second group including AS-D Chl, AS and AS-D esterase, the activities were increased prominently only in the healing stage.
These results suggest that the esterases of the second group, especially AS and AS-D esterase are enzymes which participate in the healing of pulmonary granulomatous lesions.
