L-prostaglandin D synthase expression and regulation in mouse testis and epididymis during sexual maturation and testosterone treatment after castration.

Lipocalin-type prostaglandin D synthase (L-PGDS) is highly expressed in the adult testis and epididymis of many mammals. The present study was to investigate L-PGDS expression in mouse testis and epididymis during sexual maturation, and the effects of testosterone replacement on L-PGDS expression in epididymis by in situ hybridization and immunohistochemistry. Both L-PGDS mRNA and protein were highly expressed in the interstitial tissue of adult testis. L-PGDS mRNA was first detected on d 30 after birth and exhibited an abundant signal in adult caput and cauda epididymis. L-PGDS immunostaining was first observed on d 30 after birth. There was a strong level of L-PGDS immunostaining in adult epididymis. Castrated male mice were treated with either vehicle or testosterone propionate following 3 d postcastration. L-PGDS expression steadily declined in a time-dependent fashion in control groups. No L-PGDS mRNA expression or immunostaining was detected in the controls for 12 d. When the castrated mice were treated with testosterone propionate for 5 or 12 d, L-PGDS expression was significantly increased in the whole epididymis. These data suggest that L-PGDS expression in mouse epididymis gradually declined in parallel to the declining concentration of endogenous androgen after castration and increased with the treatment of exogenous testosterone, indicating that L-PGDS expression in mouse epididymis was modulated by androgen levels. However, differential expression in different areas of the epididymis may also be influenced by factors derived from the testis. Copyright 2004 Humana Press Inc.