(189) MORPHOLOGICAL ANALYSIS OF TRANSGENDER PENIS

Abstract Introduction Erectile dysfunction (ED) is a serious medical condition that impacts quality of life. An underlying cause is loss of cavernous nerve (CN) innervation, which initiates remodeling of the corpora cavernosa of the penis including smooth muscle apoptosis and increased collagen. There are few studies of penile remodeling in patient tissue because of low availability of patient corpora cavernosa specimens, and in acquiring appropriate controls, however it is critical to ensure that our animal models adequately parallel patient conditions. Objective In this study a detailed analysis of penile morphology was performed on corpora cavernosa tissue from transgender patients in comparison to Peyronie’s controls, in order to determine if corpora cavernosa from transgender patients may be useful as a control for morphological studies of the human penis. Methods Transgender penis tissue (n = 18) was obtained from patients undergoing penectomy surgery for gender reassignment. Corpora cavernosa tissue was obtained from Peyronie’s (control, n = 8) patients that were undergoing prosthesis implantation. Immunohistochemical analysis for alpha-ACTIN, CD31, P4HB, and nNOS were performed to characterize the transgender tissue in comparison to Peyronie’s controls. Trichrome stain, hydroxyproline assay, and western analysis for alpha-actin (smooth muscle) and GAPDH, were performed to examine smooth muscle retention and collagen abundance. Primary cell cultures were established from transgender and Peyronie’s corpora cavernosa, and growth in response to SHH, BMP4 and GREM1 treatment were quantified. The effect of 17 □-estradiol on smooth muscle cultures were examined. Results Normal smooth muscle, endothelium, fibroblasts, neural tissue, collagen, and SHH signaling in corpora cavernosa from transgender patients was found in comparison to Peyronie’s controls. 17 beta-estradiol treatment did not alter smooth muscle cell growth or the response to SHH pathway signaling. Conclusions Transgender patients typically undergo 17 beta-estradiol treatment prior to penectomy. While there have been studies which document the effects of estrogen on penile embryogenesis and hypospadias, little is known about the effect estrogen may have on adult corpora cavernosa tissue. In this study a detailed analysis of penile morphology was performed in transgender patients in comparison to Peyronie’s controls, in order to determine if the transgender tissue may be useful as a control for patient studies of corpora cavernosa morphology. No apparent difference in penile morphology was observed between Peyronie’s and transgender patients. While further study is needed, transgender corpora cavernosa tissue may be useful as a control for studies of patient penile morphology. Disclosure No.