Figure 2.

Induction of collagen gel contraction by ET-1 in primary normal lung fibroblasts. (A) Floating gel contraction assay. Normal lung fibroblasts were seeded into a collagen gel matrix, and after gel polymerization, the gel was detached from the tissue culture plate and incubated in the presence or absence of ET-1 (100 nM) for 24 h. Normal lung fibroblasts have contracted their gels significantly more in the presence of ET-1. Incubation of fibroblasts with the ET-1 receptor antagonist bosentan and the ETA receptor antagonist PD156707 blocked the ability of ET-1 to induce gel contraction. Conversely, the ETB receptor antagonist BQ788 had no effect. (B) FPCL assay. Normal lung fibroblasts were seeded into a floating collagen gel matrix and incubated in the presence or absence of ET-1 (100 nM) for 24 h. Mechanical force (Dynes) was assessed by attaching the collagen gel to a tensioning-culture force monitor. Representative plot from normal lung fibroblasts treated with ET-1 (100 nM) showing the contraction stimulated force generation >24 h.