Angiotensin converting enzyme in the serum of rats with experimental silicosis

The development of silicosis in rats given an intratracheal dose of silica was followed both by normal histological procedures and by measuring the level of angiotensin converting enzyme in the serum. The histological changes demonstrated a variable response due to the uneven deposition of material given by the intratracheal route. While the enzyme activity in the serum increased in the treated group it was not well correlated with the histological changes.