Transcripts of testicular gonadotropin-releasing hormone, steroidogenic enzymes, and intratesticular testosterone levels in infertile men.

Objective To investigate the expressions of testicular GnRH and steroidogenic enzymes and their correlations with intratesticular T levels (ITT) and serum hormonal parameters in infertile men. Design Prospective case study. Setting University reproductive laboratory and clinics. Patient(s) Thirty-four azoospermic men. Intervention(s) The mRNA transcript levels of GnRH-I , GnRH-II , GnRH-R, and five steroidogenic enzymes in the testes of azoospermic men were determined by quantitative real time polymerase chain reaction. The ITT level was determined by radioimmunoassay. Main Outcome Measure(s) Transcript levels of genes and ITT determination. Result(s) The mRNA transcript levels of GnRH-I , GnRH-II , GnRH-R , cytochrome P450 side-chain cleavage ( CYP11A1 ), and 3β-hydroxy-steroid dehydrogenase type 2 enzyme ( HSD3B2 ) as well as the ITT levels were significantly increased in patients with spermatogenic failure, especially in men with Sertoli cell–only syndrome. GnRH-I and -II mRNA transcript levels positively correlated with HSD3B2 mRNA transcript levels, ITT levels, and serum FSH levels. Conclusion(s) Increased testicular GnRH transcripts, steroidogenic enzyme transcripts, and ITT levels are associated with spermatogenic failure in infertile men. Testicular GnRH is involved in the regulation of human spermatogenesis and steroidogenesis.