AN ANIMAL-MODEL OF PEYRONIES-LIKE CONDITION ASSOCIATED WITH AN INCREASE OF TRANSFORMING-GROWTH-FACTOR-BETA MESSENGER-RNA AND PROTEIN EXPRESSION

Purpose: Transforming growth factor beta (TGF-beta) is involved in num erous vital processes including tissue fibrosis. Our objective was to study the role of TGF-beta in the induction of a Peyronie's-like condi tion and to produce an animal model for the further study of Peyronie' s disease. Materials and Methods: Twenty-four adult male Sprague-Dawle y rats were divided into two groups. Different concentrations of cytom odulin, a synthetic heptopeptide with TGF-beta-like activity, were inj ected into the tunica of each rat from the first group (n = 18). Rats in the second group (n = 6) received saline injections as a control. T he tunical tissues were taken after 3 days, 2 weeks, and 6 weeks and w ere examined using Hart and Trichrome stains. In the same tissue sampl es, TGF-beta mRNA and protein expression were studied. Results: Histol ogical alterations were observed in 15 out of 18 cytomodulin-injected rats, especially in tissue examined after 6 weeks. The most prominent changes were chronic cellular infiltration, focal and diffuse elastosi s, thickening, disorganization and clumping of the collagen bundles. R esults from immunoblot revealed remarkable TGF-beta(1) protein express ion in all the cytomodulin-injected rats only after 2 and 6 weeks. No remarkable TGF-beta(2) or TGF-beta(3) protein expression was observed. TGF-beta, mRNA expression in the cytomodulin-injected rats was notice d in rats injected with higher concentrations after 3 days, while it w as expressed in all rats after 2 weeks. There was no expression in the control group after either 3 days or 2 weeks. Conclusions: Cytomoduli n can induce Peyronie's-like condition in the rat penis, which may exp lain the role of TGF-beta in the pathogenesis of Peyronie's disease.