Relaxin Alone and in Conjunction with Interferon-y Decreases Collagen Synthesis by Cultured Human Scleroderma Fibroblasts

Fibroblasts derived from the involved skin of scleroderma patients frequently display a phenotype of supernormal collagen expression when cultured. Fibroblasts displaying this phenotype derived from seven patients were treated with r~laxin (1-100 ngjml) and interferon-y (1-100 U jml), individually and in combination, to assess the relative abilities of these cytokines to down-modulate collagen synthesis and S~cretion. Scleroderma fibroblasts displayed varying sensitivities to both relaxin and interferon-yo Relaxin (100 ng/ml) decreased expression of collagen by six of seven lines tested from 8 to 59% compared to untreated cultures. Interferon-y (100 U jml) depressed collagen secretion by all seven lines in