Figure 4From: Fibroblasts and monocyte macrophages contract and degrade three-dimensional collagen gels in extended co-cultureEffect of prostaglandin E2 (PGE2) on collagen degradation. On day 4, hydroxyproline in the gels was determined. Vertical axis: hydroxyproline content (μg/gel). Horizontal axis: culture conditions. BM, blood monocytes; HFL, human fetal lung fibroblasts; INDO, indomethacin; NE, neutrophil elastase. *P < 0.05; **P < 0.01.Back to article page