Effects of systemic androgens on late-stage urethral wound healing: An animal study.

Abstract

There are limited data regarding the effects of systemic androgens on late-stage urethral wound healing. To evaluate the effects of systemic androgens on fibrosis and scar formation in late-stage urethral wound healing. Forty-five male Sprague Dawley rats were divided into three groups. First group consisted of 15 rats that were castrated on 23days of age and were given 5mg/kg testosterone undecanoate with 1/25ml cottonseed oil intraperitoneally at weekly intervals for 3weeks (castrated and replaced with testosterone rats [CAS+T] group). The castrated rats (CAS) group included 15 castrated rats. The remaining 15 rats underwent sham surgery. CAS and sham groups also received 1/25ml cottonseed oil intraperitoneally at weekly intervals for 3weeks. Furthermore, all groups were divided into three subgroups after testosterone/placebo administration (urethroplasty performed after first, second, and third weeks) in accordance with the urethroplasty timing. All animals were sacrificed 6weeks after urethroplasty. Serum testosterone level was measured, tissue samples were investigated using hematoxylin and eosin and Masson's trichrome. Alpha-SMA, Coll 1 and Coll 3 primary antibodies were applied for immunohistochemical examination. Expression of cytokines and growth factors, such as Bax, Bcl2, IL-10, IP-10, TNF-alpha, TGFb1, MMP9, Col-I, Col-III, TIMP-1, fibronectin, fibroblast growth factor 10, platelet-derived growth factor, alpha-SMA, were also evaluated in the tissues. The blood testosterone levels were significantly higher in CAS+T group at the time of urethroplasty compared with the levels in CAS group; however, this difference was not observed at the time of sacrification (p<0.001 and 0.97, respectively). Histological analysis with hematoxylin and eosin and Masson's trichrome staining revealed a significantly higher fibrosis in the sham group compared with the others. Significantly lower fibrosis was detected in the CAS group in the pairwise comparison of the pathological fibrosis area between the CAS and CAS+T groups (p<0.001). Furthermore, tissue collagen-1, collagen-3, and alpha-SMA expression levels were statistically different between CAS and CAS+T groups (p<0.001, <0.05, and <0.001, respectively). The tissue levels of BAX, TIM-1, MMP-9, Coll-I, Coll-III, TGF-beta, TNF-alpha, and IL-10 mRNA expressions in the CAS+T group were different than the levels in CAS group (as <0.5-fold and >1.5-fold changes, respectively). The expressions of all these markers were significantly higher in the sham group. The subgroup analysis of CAS+T group (urethroplasty performed after first, second, and third weeks) revealed similar histopathological wound healing findings. Debate continues on the effects and benefits of androgen use regarding urethral healing. There are two main routes for administration as systemic or local. This study focuses on the late-stage histologic and biochemical effects of systemic androgens. Systemic androgens adversely affect wound healing and cause abnormal extracellular matrix as well as scar formation.