Dermal Fibrosis Following Subcutaneous Injections of Serotonin Creatinine Sulphate.

Abstract

Serotonin creatlnine sulfate was injected subcutaneously twice daily into rats in 8 mg doses for periods of up to 342 consecutive days. After approximately 30 days of injections, a progressive collagenous and fibrous proliferation within the dermis developed, with increased vascularity, hyperplasia of the epidermis, vascular changes in arterioles of the dermis, and diminution in skin appendages, all at sites of serotonin injections. Control injections of physiologic saline and carbon tetrachloride did not result in similar changes. These findings appear to lend some support to the hypothesis that serotonin causes the cardiac valvular fibrosis observed in patients with meta-static carcinoid tumor.