Endocrine Abstracts

JOINT381

Research aim: Diabetes type 1 can negatively influence testicular function and fertility but the pathomechanisms on the testicular level remains to be elucidated. Therefore, the aim of the study was to evaluate effects of diabetes mellitus type 1 disease on testicular function.

Material and methods: BB/OKL rats developed type 1 diabetes during adolescence. One group received sufficient insulin treatment with excellent HbA1c levels, a second group insufficient amounts of Insulin and had a poor glycaemic control (8 rats per group). Leydig-, Sertoli-, and Germ-cell function was analysed on RNA and protein level. Furthermore, androgens were measured in serum samples and after extraction from testicular tissue with LC–MS/MS. Immunhistochemistry was performed and the inflammatory status and apoptosis was evaluated.

Results: After diabetes manifestation 25–33% of the rats developed testicular atrophy compared to none in the healthy control group. In the atrophic testis, we found a strong reduction of elongated and round spermatids and spermatocytes by more than 80%. Leydig cells showed a hyperplasia with a strong and significant upregulation of steroidogenic enzymes on RNA and on protein level (Star by 106%/94%, 3beta-HSD by 177%/203%, 17Beta-HSD by 276%/134%, CYP11A1 by 66%/65% and CYP17A by 1859%/2202%; all P<0.001). Furthermore, we measured significantly higher concentrations of androgens and INSL3 levels in the atrophic testis. In contrast, germ cells showed a depletion with a strong downregulation of DDX4 (by 78,19%/) and Crem (by 51,54%). In addition, we found a strong increase of oxidative stress, apoptosis and inflammation. SF-1 (+965%) and DHH (by 2575%) pathways were strongly upregulated in the atrophic testis and might me a possible pathomechanism.

Conclusion: Diabetes type 1 can induce testicular atrophy with germ cell depletion, apoptosis and increased inflammation. In parallel, Leydig cell hyperplasia develops with an upregulation of steroidogenic enzymes, and higher intratesticular testosterone levels. Therefore, diabetes type 1 can negatively influence reproductive function and fertility in male rats.