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The effects of polydeoxyribonucleotide (PDRN), an agonist of the A2A adenosine receptors which when activated positively influences sperm activity, were tested in an experimental testicular ischaemia/reperfusion injury model. Anaesthetized male Sprague-Dawley rats were subjected to testicular torsion-induced ischaemia, followed by reperfusion (TI/R). Immediately after detorsion, randomized animals, including SHAM, received intraperitoneal injections of: (i) vehicle (1 mL/kg 0.9% NaCl solution); (ii) PDRN (8 mg/kg); (iii) DMPX (3,7-dimethyl-1-propargilxanthine, 0.1 mg/kg); or (iv) PDRN (8 mg/kg) + DMPX (0.1 mg/kg). Animals were euthanized at 1, 7 and 30 days following reperfusion. Vascular endothelial growth factor (VEGF) expression is normally associated with adenosine A2A receptor stimulation. After treatment, VEGF mRNA/protein expression quantified by qPCR and Western blot, vascular endothelial growth factor receptor-1 (VEGFR1) and endothelial nitric oxide synthase (eNOS) mRNA measured by qPCR, VEGF and VEGFR1 assessed using immunohistochemical methods, histological staining and spermatogenic activity were all analysed. Testis ischaemia-reperfusion (TI/R) injury caused increases in VEGF mRNA and protein, VEGFR1 and eNOS mRNA, histological damage and reduced spermatogenic activity. Immunostaining showed a lower expression of VEGF in germinal epithelial cells and a strong expression of VEGFR1 in Leydig cells after TI/R. PDRN administration increased significantly VEGF message/protein, VEGFR1 and eNOS message, decreased histological damage and ameliorated spermatogenic activity. PDRN might be useful in the management of testicular torsion., (© 2011 The Authors. International Journal of Andrology © 2011 European Academy of Andrology.)

Purpose: Testicular torsion is a medical emergency that requires immediate diagnosis and treatment to avoid subsequent testicular injury and infertility. PPARs are a family of nuclear hormone receptors belonging to the steroid receptor superfamily. Three PPAR isotypes (alpha, beta/delta and gamma) encoded by separate genes and showing different tissue distribution patterns have been identified. PPARbeta/delta is expressed in testis and its role is largely unknown. We tested whether pharmacological activation of PPARbeta/delta might protect the testis from ischemia and reperfusion injury., Materials and Methods: Adult male Sprague-Dawley rats were subjected to 1-hour testicular ischemia, followed by 24 hours of reperfusion. Sham testicular ischemia-reperfusion rats served as controls. The animals were randomized to receive immediately after detorsion 1) L-165,041 (4 mg/kg intraperitoneally), a potent agonist of PPARbeta/delta, 2) GW9662 (Calbiochem(R)) (4 mg/kg intraperitoneally), an antagonist of PPAR, 3) L-165,041 (4 mg/kg intraperitoneally) plus GW9662 (4 mg/kg intraperitoneally) concomitantly or 4) vehicle (1 ml/kg 10% dimethyl sulfoxide/NaCl solution). We evaluated testicular extracellular signal regulated kinase, tumor necrosis factor-alpha and interleukin-6 by Western blot. We also investigated PPARbeta/delta activation by Western blot, mRNA expression and organ damage., Results: Testicular ischemia-reperfusion injury caused a significant increase in extracellular signal regulated kinase, tumor necrosis factor-alpha and interleukin-6 expression in each testis. Furthermore, histological examination revealed marked damage. L-165,041 administration increased the PPARbeta/delta message and protein, inhibited extracellular signal regulated kinase, tumor necrosis factor-alpha and interleukin-6 expression, and decreased histological damage. Concomitant administration of GW9662 reversed the protection exerted by PPARbeta/delta agonist., Conclusions: These findings indicate that PPARbeta/delta agonists might be an attractive therapeutic candidate for managing testicular torsion.

Nuclear factor kappa-B (NF-kappaB), mitogen-activated protein kinase3/MAPK1 and MAPK8 are involved in testicular ischemia reperfusion injury (testicular-I/R). NF-kappaB knock-out mice (KO) subjected to testicular-I/R have a reduced testicular damage, blunted MAPK8 activation and enhanced MAPK3/MAPK1 activity. To better understand the role of MAPK3/MAPK1 up-regulation during testicular-I/R, we investigated the effects of PD98059, an inhibitor of MAPK3/MAPK1, in KO mice during testicular-I/R. KO and wild-type (WT) animals underwent 1 h testicular ischemia followed by 24 h reperfusion or a sham testicular-I/R. Animals received either PD98059 (5 mg/kg/ip) or its vehicle. MAPK3/MAPK1, BAX, caspase-3 and -9 and TNF-alpha expression were assessed along with histological examination and an immunostaining for protein of apoptosis. Testicular-I/R caused a greater increase in MAPK3/MAPK1 in KO than in WT animals in both testes. KO mice had a lower expression of the apoptotic proteins and TNF-alpha as well as reduced histological damage compared to WT. Immunostaining confirmed the lower expression of BAX in the Leydig cells of KO mice. Administration of PD98059, abrogated MAPK3/MAPK1 expression and slightly reduced TNF-alpha but did not improve or reverse the histological damage in KO. PD98059 significantly reduced the histological damage in WT mice and markedly reduced the apoptotic proteins in KO and WT mice. These results suggest that testicular-I/R triggers also a pathway of organ damage involving MAPK3/MAPK1, TNF-alpha, BAX, caspase-3 and -9 that activates an apoptotic machinery in an NF-kappaB independent manner. These findings should contribute to better understand testicular torsion-induced damage.