Bronchoalveolar Lavage. The results of analysis of bronchoalveolar lavage fluid are presented in Figure 2. In the saline-exposed sheep, total cells from lavage averaged 250,000/ml and did not vary significantly in the course of the experiment. Similarly, the levels of macrophages, neutrophils, fibronectin, and procollagen 3 did not change. In the latex-exposed sheep, we have previously reported a clear increase in total cells from lavage at month 1 to eight times the control value, and at month 12, this had returned to the level of saline-exposed sheep. From that point and after, there was no significant difference in levels of macrophages, neutrophils, fibronectin, and procollagen 3 between latex-exposed and saline-exposed sheep. In the asbestos-exposed sheep, total cells were clearly increased through the experiment; and one year after exposure, total cells in bronchoalveolar lavage fluid remained at 150 percent of controls, macrophages at 150 percent of controls, and neutrophils at 285 percent of controls. Fibronectin in bronchoalveolar lavage fluid was significantly elevated only in the asbestos-exposed sheep, and the levels increased throughout the experiment. Procollagen 3 in lavage fluid increased significantly early and returned to control levels at month 4 after exposure (Fig 2). Albumin was increased significantly only after month 4, and it paralleled the second increase in fibronectin ordered via My Canadian Pharmacy (data not shown).