Serum peptide III-procollagen and ACE in asbestos workers.

Type-III-procollagen peptide (P-III-P) concentration and angiotensin-converting-enzyme (ACE) activity were measured in the serum of asbestos workers. The subjects were classified into four groups (A, B, C, D) according to the duration of exposure (in years). A gradual increase of ACE activity in group B and P-III-P concentration in group C was found. The increase in ACE activity can be regarded as the response to the progressing inflammatory state, and the increase in P-III-P concentration may be related to the fibrosis of the lung tissue.