Mineralocorticoid receptor expression in human penile corpus cavernosum

Objectives: Mineralocorticoid receptor (MR) is known to play physiological and pathophysiological roles in the cardiovascular system, and MR activation directly damages these organs. The aim of this study was to evaluate the expression of MR and 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) in the human penile corpus cavernosum. Methods: MR and 11β-HSD2 expression was assayed in human penile tissues, and also in human renal tissues as a positive control. Expressions of MR mRNA and 11β-HSD2 mRNA were evaluated using reverse transcription polymerase chain reaction (RT-PCR). MR and 11β-HSD2 were visually identified using immunofluorescence analysis. Results: MR mRNA expression in human penis was confirmed by RT-PCR. On quantitative RT-PCR analysis, 11β-HSD2 mRNA expression was detected at minimal levels in penile tissue. Immunofluorescence analysis revealed positive staining for MR and negative staining for 11β-HSD2 in smooth muscle cells of the corpus cavernosum. Conclusions: This study demonstrated the presence of MR and the absence of 11β-HSD2 in human penile corpus cavernosum. Considering that MR activation causes various organ damages, MR blockade in human penile corpus cavernosum may have therapeutic benefits. Investigations for the penile effects of MR activation have the potential to provide new treatment approaches for erectile dysfunction. J. Med. Invest. 60: 21-26, February, 2013