Effects of histamine and hydroxyradical on collagen matrix contraction

We studied the effects of histamine and hydroxyradical on contraction of collagen matrix induced by the interactions between fibroblasts and collagen fibrils. Histamine had a stimulatory effect on the collagen gel contraction, and this stimulation could not be recognized by pyrilamine, an H₁ antagonist. On the other hand, cimetidine, an H₂ antagonist, had no effect on the histamine stimulated contraction of collagen gel. Collagen matrix contraction was significantly inhibited by influence of hydroxyradical, produced by ascorbate and copper ion, for more than 3 hours. These facts suggested that both histamine and hydroxyradical, mediators on the inflammation, might play important roles in granuration tissue contraction.