The role of histamine in wound healing. II. The effect of antagonists and agonists of histamine receptors (H1 and H2) on collagen levels in granulation tissue

The effects of mepyramine (H₁-receptor antagonist), cimetidine (H₂-receptor antagonist), IEM-813 (H₁-receptor agonist) and 4-Met-Hi (H₂-receptor agonist) on collagenogenesis processes in subcutaneous implanted sponges of rats were studied. Administration into sponges of cimetidine 30 min before histamine injection blocked both the stimulatory effect of low histamine doses and the inhibitory effect of high histamine doses on collagen formation. Low doses of 4-Met-Hi increased collagen levels but reduced the levels at high doses. Mepyramine and IEM-813 did not influence collagen biosynthesis.