¹Department of Urology, University of Yamanashi, Faculty of Medicine, Yamanashi, Japan

Correspondence: Dr M Komuro, Department of Urology, University of Yamanashi, Faculty of Medicine, Yamanashi, 1110 Tamaho, Yamanashi 409-3898, Japan. E-mail: mkomuro@yamanashi.ac.jp

Received 16 May 2005; Revised 12 September 2005; Accepted 12 September 2005; Published online 20 October 2005.

Abstract

Prostaglandin E1 leads to penile erection, mainly via prostaglandin E2 (EP) receptors. This study aimed to identify the expression profile of EP receptor genes in human corpus cavernosum. Using the quantitative real-time reverse transcription polymerase chain reaction, the mRNA levels of EP receptor subtypes were measured. In addition, expressions of EP receptor subtype proteins were determined by immunohistochemical method. Among the four subtypes, EP4 receptor mRNA expression was the highest, and EP2 receptor mRNA followed, whereas EP1 and EP3 receptor mRNAs were hardly observed. Expression level of EP4 receptor mRNA was significantly higher than that of EP2 receptor mRNA. Expression of both EP2 and EP4 receptor proteins were clearly detected in the cavernous smooth muscle. These results may suggest that EP4 receptor plays an important role among four EP receptor subtypes for relaxation of smooth muscle in the human corpus cavernosum.