Presentation Authors: Satoshi Nozaki*, Shoiciro Iwatsuki, Tomoki Takeda, Hiroki Kubota, Hiroyuki Kamiya, Shoichi Sasaki, Yukihiro Umemoto, Takahiro Yasui, Nagoya, Japan
Introduction: During microsurgical testicular sperm extraction, many cases exhibit increased leakage of testicular interstitial fluid. The interstitial tissue mostly comprises Leydig cells that are regulated by the luteinizing hormone (LH). The study aimed to investigate the relationship between LH signals and interstitial edema using mice with impeded sperm production ability in which LH signaling of Leydig cells had been suppressed.
Methods: We used 6-week-old C57BL/6J mice to create a leuprorelin group (L group) and a control group (C group). L group was subcutaneously injected with the LHRH agonist leuprorelin acetate at 30 mg/kg and C group had received subcutaneous injections of a physiological saline solution. Testes were extracted at 4 and 8 weeks after administration and testicular weights were measured. Hematoxylin- and eosin-stained specimens were used to measure seminiferous tubule diameter and interstitial tissue area per testicular weight. We measured the proportion of seminiferous tubules in which the elongated spermatids had disappeared and evaluated sperm production dysfunction.
Results: Testicular weight was significantly lower (P < 0.01) in L group (79.7 and 81.4 mg at 4 and 8 weeks after administration, respectively) than in C group (101.5 and 103.6 mg, respectively). Seminiferous tubule diameter was shorter in L group (174.2 and 166.7Âµm at 4 and 8 weeks, respectively) than in C group (182.5 and 176.3Âµm, respectively). Interstitial tissue area per testicular weight was significantly higher (P < 0.01) in L group (1.79 and 1.13 at 4 and 8 weeks, respectively) than in C group (1.13 and 1.03, respectively). In addition, sperm production ability was impaired in L group but normal in C group. The proportion of seminiferous tubules in which elongated spermatids had disappeared in L group was 8.3 and 20.3% at 4 and 8 weeks, respectively, but remained at 0% for C group at both 4 and 8 weeks.
Conclusions: This study first revealed that LH signals are involved in the homeostasis of testicular interstitial fluid and that abnormal LH signals can impair sperm production. Results suggest that regulating LH signals could improve testicular interstitial edema and sperm production ability.