Effects of melatonin on lipid peroxidation and antioxidant enzymes in streptozotocin-induced diabetic rat testis

Aim： To examine the effects of melatonin treatment on lipid peroxidation （LPO） and the activities of antioxidant enzymes in the testicular tissue of streptozotocin （STZ）-induced diabetic rats. Methods： Twenty-six male rats were randomly divided into three groups as follows： group Ⅰ, control, non-diabetic rats （n = 9）; group Ⅱ, STZ-induced, untreated diabetic rats （n = 8）; group Ⅲ, STZ-induced, melatonin-treated （dose of 10 mg/kg·day） diabetic rats （n = 9）. Following 8-week melatonin treatment, all rats were anaesthetized and then were killed to remove testes from the scrotum. Results： As compared to group Ⅰ, in rat testicular tissues of grouap Ⅱ, increased levels of malondialdehyde （MDA） （P 〈 0.01） and superoxide dismutase （SOD） （P 〈 0.01） as well as, decreased levels of catalase （CAT） （P 〈 0.01） and glutathione peroxidase （GSH-Px） （P 〉 0.05） were found. In contrast, as compared to group Ⅱ, in rat testicular tissues of group Ⅲ, levels of MDA decreased （but this decrease was not significant, P 〉 0.05） and SOD （P 〈 0.01） as well as CAT （P 〈 0.05） increased. GSH-Px was not influenced by any of the treatment. Melatonin did not significantly affect the elevated glucose concentration of diabetic group. At the end of the study, there was no significant difference between the melatonin-treated group and the untreated group by means of body and testicular weight. Conclusion： Diabetes mellitus increases oxidative stress and melatonin inhibits lipid peroxidation and might regulate the activities of antioxidant enzymes of diabetic rat testes.

Effects of extra-corporeal shock waves on penile hemodynamics and histopathology in rats

Aim: To study the effect of extra-corporeal shock wave (ESW) on the penile hemodynamics and histopathology in rats. Methods: Adult male Sprague-Dawley rats were divided at random into 3 groups. ESW application was performed with a Siemens Lithostar with the rats under anesthesia lying prone on the balloon probe. Rats in Group Ⅰ received a total of 1000 shocks at 18 kV and immediately underwent hemodynamic evaluation performed by direct electrostimulation of the cavernous nerve and measurement of intracavernous pressure (ICP). Rats in Group Ⅱ received 3 times 1000 shocks at 18 kV at weekly intervals and hemodynamic evaluation was performed 1 month after the last ESW application. Group Ⅲ served as the control. Histopathological examinations of penile tissues were done on Masson's trichrome and hematoxylin and eosin stained sections. Results: Penile hemodynamic evaluation showed a trend toward a diminished mean maximal ICP, duration of erection, ICP during the plateau phase and maximal ICP/blood pressure ratio in Group Ⅰ, although there was no significant significance. The mean latency period in Groups Ⅰ and Ⅱ was prolonged. Petechial bleeding within tunical layers and small loci of hemorrhage within the corpora cavernosa were observed in Group Ⅰ. However, histopathological examination failed to reveal any significant differences between the groups in terms of smooth muscle content, tunical thickness, organization of collagen bundles and elastic fiber-lattice framework. Conclusion: ESW has certain damaging effects on the penis. (Asian J Androl 2002 Dec; 4: 249-253)

Multi-center evaluation of oxidation-reduction potential by the MiOXSYS in males with abnormal semen

According to the World Health Organization(WHO),oxidative stress(OS)is a significant contributor to male infertility.SeminalOS can be measured by a number of assays,all of which are either costly or time sensitive and/or require large semen volume andcomplex instrumentation.One less expensive alternative is to quantify the oxidation-reduction potential(ORP)with the MiOXSYS.In this international multi-center study,we assessed whether ORP levels measured by the MiOXSYS could distinguish semensamples that fall within the 2010 WHO normal reference values from those that do not.Semen samples were collected from 2092patients in 9 countries;ORP was normalized to sperm concentration(mV/10^6 sperm/ml).Only those samples with a concentration>1×10^6 sperm ml1 were in eluded.The results showed that 199 samples fell within the WHO no rmal refere nee range while theremaining 1893 samples did not meet one or more of the criteria.ORP was negatively correlated with all semen parameters(P <0.01)except volume.The area under the curve for ORP was 0.765.The ORP cut-off value(1.34 mV/10^6 sperm/ml)was able todifferentiate specimens with abnormal semen parameters with 98.1%sensitivity,40.6%specificity,94.7%positive predictivevalue(PPV)and 66.6%negative predictive value(NPV).When used as an adjunct to traditional semen analysis,ORP levels mayhelp identify altered functional status of spermatozoa caused by OS in cases of idiopathic male infertility and in male partners ofcouples sufferi ng recurre nt pregna ncy loss,and thereby directi ng these men to relevant medical therapies and lifestyle modificati ons.