Comparison of intraperitoneal and intratesticular GYY4137 therapy for the treatment of testicular ischemia reperfusion injury in rats

Abstract

Objective To investigate the efficacy of intraperitoneal GYY4137 therapy and intratesticular GYY4137 therapy to testicular ischemia reperfusion injury in an experimental rat model. Methods 4 groups were set up as the sham-operation group (group A), torsion/detorsion (T/D) group (group B), torsion/detorsion plus intraperitoneal GYY4137 (G-IP) group (group C), and torsion/detorsion plus intratesticular GYY4137 (G-IT) group (group D). Group A was the control group. In order to form a testicular T/D model, the left testis was operated and the rotation reached 720 degrees clockwise which lasted 1 hour before reperfusion in group B, group C and group D. Group C accepted 100 μmol/kg of GYY4137 intraperitoneally half an hour after testicular rotation, while group D was treated with the same dose by intratesticular injection. Four hours after detorsion, the testis was collected and subsequently assessed. The histopathological change of testis was observed with the help of hematoxylin and eosin (HE) staining; the expression of malondialdehyde (MDA) and superoxide dismutase (SOD) was measured; the apoptosis index was determined through TdT-mediated dUTP nick end labeling (TUNEL) methods; immunohistochemistry method was used to evaluate the expression of B cell lymphoma/leukemia-2 associated X protein (bax) and cysteinyl aspartate-specific protease (Caspase)-3; tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β expression was detected through Western blotting; real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) was used to examine the expression of bax, Caspase-3, TNF-αand IL-1β. Results Group B showed significant changes in histology and an enhancement in the level of oxidative stress and apoptosis compared to the group A, which was relatively ameliorated in group C and group D. Compared with group A (1.21±0.20, 0.86±0.05), group B (5.13±0.26, 0.22±0.04) showed an increase in the MDA level and a decrease in SOD expression while the changes seemed to be eased in group C (3.26±0.23, 0.42±0.04) and group D (2.42±0.24, 0.58±0.04, t=37.790, 3.710, 17.040, 24.220, 11.450, 20.070, P<0.05). The expression of Caspase-3 and bax turned out to be strengthened by T/D in group B and relatively decreased with GYY4137 treatment in both group C and group D. Moreover, an enhancement of TNF-α and IL-1β expression was found in group B (0.774±0.042, 0.674±0.037) compared with group A (0.147±0.022, 0.136±0.018) while an inhabitation by GYY4137 in group C (0.425±0.029, 0.417±0.030) and group D (0.331±0.027, 0.308±0.025) was detected (t=21.620, 17.060, 28.060, 25.920, P<0.05). Compared with group B (5.35±0.43, 3.76±0.31, 4.35±0.31, 3.86±0.34), the expression of bax, Caspase-3, TNF-α and IL-1β was inhibited in group C (3.86±0.32, 2.56±0.21, 3.08±0.25, 2.92±0.28) and group D (3.78±0.36, 2.23±0.22, 2.96±0.26, 2.56±0.25). GYY4137, moderating these observed changes, displayed a more protective effect in group D compared to group C. The above results showed statistically significance (t=8.790, 10.130, 10.080, 6.750, 8.850, 12.730, 10.860, 9.740, P<0.05). Conclusion Our study indicated that GYY4137 treatment has obvious protective effect on testicular ischemia reperfusion injury in rats, and the efficacy of intratesticular therapy with GYY4137 is greater than that of intraperitoneal therapy, which may provide a more valuable approach for testicular torsion therapy. Key words: Testicular ischemia reperfusion; GYY4137; Apoptosis; Inflammation; Oxidative stress