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 3beta-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.