Injury In Rat Testis Research Articles

The therapeutic effect of cerium oxide nanoparticle on ischaemia/reperfusion injury in rat testis

Testicular torsion is a dangerous urogenital disorder which is caused by twisting of spermatic cord, and unless immediate treatments happen at a proper time, oxidative stress, occurred during ischaemia reperfusion, finally leads to irreversible disintegration of testicular tissue. One of the first preventive lines is to administrate antioxidant factors. In the present study, we investigate the therapeutic effect of cerium oxide nanoparticle on the injury. We divided 45 rats into nine groups, subjected eight groups to testicular torsion-detorsion, injected different doses of cerium oxide nanoparticle into the peritoneum of six groups and analysed all the groups regarding spermatogenetic indices including sperm count, sperm viability and Johnson mean. Our results showed that cerium oxide nanoparticle can alleviate oxidative stress in testis, and this alleviation promotes the reproductive indices as the concentration of cerium oxide nanoparticles increases. The catalase-mimetic and superoxide dismutase-mimetic activities of cerium oxide nanoparticle are the most probable theories to explain the antioxidant effect of the nanoparticle.

Protective effect of MOTILIPERM in varicocele-induced oxidative injury in rat testis by activating phosphorylated inositol requiring kinase 1α (p-IRE1α) and phosphorylated c-Jun N-terminal kinase (p-JNK) pathways

Context: MOTILIPERM was prepared as a mixture of extracts of three medicinal herbs [roots of Morinda officinalis How (Rubiaceae), outer scales of Allium cepa L. (Liliaceae) and seeds of Cuscuta chinensis Lamark (Convolvulaceae)].Objective: To investigate the role of reactive oxygen species (ROS)-based endoplasmic reticulum (ER) stress in a rat model of varicocele and the therapeutic efficacy of MOTILIPERM in this model.Materials and methods: Sixty male rats were divided into five experimental groups: a normal control group (CTR + vehicle), a control group administered MOTILIPERM 200 mg/kg (CTR + M 200), a varicocele-induced control group (VC + vehicle) and two varicocele-induced groups administered MOTILIPERM 100 (VC + M 100) or 200 (VC + M 200) mg/kg for 4 weeks. Testis weights were recorded and serums were assayed for hormone concentrations. Tissues were subjected to semen analysis, histopathology, analyses of ER response protein expression levels and oxidative stress were assessed by measuring ROS, reactive nitrogen species (RNS), malondialdehyde (MDA) level and ratios of total glutathione (GSH)/oxidized GSH (GSSG).Results: MOTILIPERM treatment of varicocele-induced groups significantly increased left testis weight, testosterone level, sperm motility, count and spermatogenic cell density. ER-response protein expression levels were dose-dependently decreased in VC + M 200 group compared with VC + vehicle group. MOTILIPERM treatment also decreased MDA and ROS/RNS level but increased GSH/GSSG ratio.Discussion and conclusions: This study suggests that ROS-related ER stress may play a major role in varicocele-induced infertility and MOTILIPERM, a novel compound targeting ROS-based ER stress, may be therapeutically useful in treatment of varicocele, or as a supplement for the treatment of infertility.

Effects of platelet-rich plasma against experimental ischemia/reperfusion injury in rat testis

Testicular torsion is a common problem and, to date, there is no agent to preserve testicular function following detorsion. Platelet-rich plasma (PRP), with its rich growth factor composition, has proven beneficial in regenerative therapy. It is believed that PRP has not been studied in testis for ischemia/reperfusion (I/R) injury. This study investigated the effect of PRP in an I/R rat model 1 month after detorsion. Of 24 adult male Sprague-Dawley rats, 18 were randomly assigned into three groups, with six in each: control, I/R and I/R+PRP. The PRP was prepared from the remaining six. Each group underwent right orchiectomy. Ischemia was performed by rotating the left testis 720° and fixing with a nylon suture for 4h. Reperfusion occurred 4h later by removing the suture, and PRP was administered at a dose of 10μl (2000×109/l) into the left testis via the intraparenchymal route. Animals were sacrificed at the fourth week, and testes were taken for malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), myeloperoxidase (MPO), transforming growth factor β (TGF-β), and caspase-3 measurements. Ischemia/reperfusion caused a significant increase in MDA, MPO and caspase-3 activity, and significant decrease in GSH levels and SOD activity. The PRP treatment helped correct the alterations in SOD, caspase-3, and MPO activities and MDA levels. However, the mean MDA level and MPO activity were not totally restored compared with the controls. Serum testosterone levels of the I/R group were significantly lower compared with the control and I/R+PRP groups. TGF-β and caspase-3 protein expressions were significantly higher in the I/R group compared with the control group and were low with PRP administration compared with I/R groups (summary Table). The findings of the present study suggest that PRP, by inhibiting neutrophil infiltration and oxidative stress and increasing antioxidant defense, exerts protective effects on testicular tissues against I/R. This study had some limitations: a scoring system was not used in the assessment of spermatogenesis in the histopathological findings and specific testis cell types were not histologically assessed. In light of the biochemical, histological and, especially, hormonal findings, intraparenchymal PRP injection may have a protective effect in testicular tissue against I/R injury.

The histopathological evaluation of healing effects of vitamin C administered before methotrexate therapy on testicular injury induced by methotrexate.

Methotrexate (MTX) leads to acute toxic side effects in tissues or organs containing rapidly dividing cells such as seminiferous tubules. In this study, we investigated the protective effects of vitamin C against MTX-induced injury in rat testis. A total of 31 rats were divided into 4 groups, including the control group. The study was completed within 4 weeks and the rats received daily doses of 2 mL/kg SF, 100 mg/kg vitamin C and 10 mg/kg/day MTX i.p according to their groups. The mean seminiferous tubular diameter, germinal epithelial cell thickness, and mean testicular biopsy score were determined by histologic examination of each group. The vitamin C + MTX group showed more similarity with the control group. Statistically significant results were achieved between groups as for mean seminiferous tubular diameter, germinal epithelial cell thickness, and mean testicular biopsy score. When compared with the group which received vitamin C after MTX therapy, values for mean seminiferous tubular diameter, germinal epithelial cell thickness, and mean testicular biopsy score were significantly higher in the group which received vitamin C before initiation of MTX therapy. Vitamin C decreased MTX-induced testicular histological injuries, especially when used before MTX therapy.

PD35-12 KDM5A, A HISTONE H3K4 DEMETHYLASE, REGULATES SPERMATOGENESIS VIA ITS ACTION ON GERM CELL

INTRODUCTION AND OBJECTIVES: Cisplatin is a widely used chemotherapeutic agent for the treatment of various genitourinary tumors. Although it is a very effective, its use is limited by its renal and testicular toxicity. Mesenchymal stem cells (MSCs) are pluripotent undifferentiated cells that have the ability to differentiate and divide into another cell types and can self renew. Our aim was to investigate the possible protective role of MSCs against Cisplatin induced testicular apoptosis and damaged oxidant/antioxidant balance in rats. Furthermore, we explored the involvement of apoptotic markers in the pathogenesis of testicular toxicity and their role in monitoring treatment. METHODS: A total of 30 male Sprague Dawley rats were used for the experiment. They were divided into 3 groups: Group 1 served as control group received intraperitoneal (IP) saline, Group 2 (Cisplatin group) received a single IP dose of Cisplatin 7mg/kg and Group 3 (Stem Cells group) received the same IP single dose of Cisplatin and was administered BM-MSCs (2x10 cells) by penile vein injection 24h after the Cisplatin injection. Testicular weight and plasma testosterone level were determined along with testicular malondialdehyde (MDA) and reduced glutathione (GSH) levels as oxidative stress markers. Testicular gene expressions of Caspase-3 and mitogen activated protein kinase (MAPK) were estimated by real time-PCR. Histopathological examination for testicular tissues was also done. RESULTS: Cisplatin induced a significant reduction in testicular weights, plasma testosterone and testicular GSH levels in addition to significant elevation of testicular MDA levels and gene expressions of Caspase-3 and MAPK when compared with control group (p<0.05). Histopathology showed lower tubular diameters and depletion of germ cells, irregular small seminiferous tubules with Sertoli cells only were observed in Cisplatin group. MSCs injection significantly corrected these changes in both biochemical and histopathological parameters. CONCLUSIONS: There is a significant role of oxidative and apoptotic markers in the pathogenesis of Cisplatin induced oxidative injury in rat testis. Cisplatin treatment markedly impaired testicular function in rats through mechanisms that could be significantly salvaged with co-administration of MSCs. To our knowledge, this is the first report in the literature that address the protective role of MSCs in Cisplatin induced testicular toxicity; however, further studies are needed to validate our findings.

Protective effects of propolis on methotrexate-induced testis injury in rat.

Propolis is an adhesive substance which is collected and used by honeybees. Propolis is a potent antioxidant and a free radical scavenger. This study was designed to determine whether propolis could protect against dysfunction and oxidative stress induced by methotrexate-induced injury in rat testis. A total of 40 male Wistar albino rats were divided into four groups: group 1 was the untreated control. On the eighth day of the experiment, groups 2 and 3 received single intraperitoneal injections of methotrexate (MTX) at 20mg/kg. Groups 3 and 4 received 100mg/kg/day propolis (by oral gavage) for 15 days by the first day of the experimental protocol. Then the rats were decapitated under anesthesia, and their testes were removed. The histopathological and biochemical analysis along with apoptosis assessment of testis tissues were compared. Immunohistochemical analysis of Heat shock protein-70 (HSP-70) and Proliferating Cell Nuclear Antigen (PCNA) were performed. The phenolic characterization of propolis was performed by Liquid chromatography-mass spectrometry (LC-MS/MS). Methotrexate caused tended to increase in malondialdehyde level and in the number of apoptotic cells; it also caused a decrease in MSTD and JTBS, PCNA and HSP-70 expression and xanthine oxidase levels in group 2. Propolis prevented the rise in malondialdehyde, xanthine oxidase levels and HSP-70 expression and improved testicular morphology and JTBS. It was found that, methorexate gives rise to serious damage in the testes and propolis is a potent antioxidant agent in preventing testicular injury.

The effect of vitamin E and L-carnitine against methotrexate-induced injury in rat testis

Methotrexate (MTX), used commonly as an antimetabolite drug in cancer therapy, leads to acute toxic side effects in tissues or organs containing rapidly dividing cells, such as bone marrow, gastrointestinal mucosa, and seminiferous tubules. In this study, we investigated the protective effects of vitamin E and L-carnitine against MTX-induced injury in rat testis. Rats were divided into 4 groups, including the control group. The study took 17 days and the animals received daily doses of 0.5 mL/kg saline, 250 mg/kg vitamin E, or 500 mg/kg L-carnitine intraperitoneally. The experimental groups received 20 mg/kg methotrexate intraperitoneally on days 3 and 10. Weight loss, testicular weight loss and marked histological injuries, increased malondialdehyde levels, and decreased superoxide dismutase levels were only observed in the MTX-treated groups. Vitamin E and L-carnitine treatments did not affect MTX-induced weight loss or testicular weight loss, but they inhibited MTX-induced testicular histological injuries. Vitamin E and L-carnitine treatments suppressed the increases in malondialdehyde levels and the decreases in superoxide dismutase levels. Vitamin E and L-carnitine treatments decreased MTX-induced testicular histological injuries, and these results were supported by biochemical measurements.

The short term effects of resveratrol on ischemia–reperfusion injury in rat testis

PurposeThe purpose of this study was to identify changes taking place in the rat testis at the 24th hour of reperfusion following testicular torsion and to evaluate the effects of resveratrol (RSV), a powerful antioxidant, in preventing these changes using novel biochemical parameters and histopathology. MethodsEighteen adult male rats were divided into three groups: Sham-operated (S), torsion/detorsion (T/D), and T/D+RSV groups. In the T/D group, testicular ischemia was achieved by rotating the left testis 720° clockwise for 4h. In the T/D+RSV group, 20mg/kg RSV was administered intraperitoneally 30min before detorsion. All rats were sacrificed 24h after detorsion. Serum and tissue malondialdehyde (MDA) concentrations, ischemia modified albumin (IMA), total oxidative status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), and histopathological damage score were analyzed. ResultsSerum MDA, IMA, TOS, and OSI levels rose significantly in the T/D group. Serum MDA and IMA values were lower in the T/D+RES groups, but not significantly. OSI and TOS values were lower in the T/D+RES group, and the difference was significant. TAS values decreased significantly in the T/D group and rose in the T/D+RSV group, but not significantly. Ipsilateral tissue MDA values were significantly elevated in the T/D group and decreased in the T/D+RSV group, but not significantly. Apoptosis and histopathological damage increased significantly in the T/D group and decreased significantly in the T/D+RSV group. In the contralateral testis, apoptosis increased significantly in the T/D group. It decreased significantly in the T/D+RSV group. ConclusionsOur findings show that RSV had a protective effect against oxidative damage induced with a testicular T/D model, especially at the antiapoptotic and histopathological level. OSI may be a good guide to the clinical status of testicular T/D.

The protective effects of grape seed extract on MDA, AOPP, apoptosis and eNOS expression in testicular torsion: an experimental study

Grape seed proanthocyanidin extract (GSPE) is a potent antioxidant and a free radical scavenger. This study was designed to determine whether GSPE could protect against dysfunction and oxidative stress induced by torsion-detorsion injury in rat testis. A total of 45 male Wistar albino rats were divided into five groups: control group, sham group, torsion-detorsion (T/D) group, T/D + GSPE group, GSPE group. GSPE was administrated 100 mg/kg/day with oral gavage over seven days before torsion. Testicular torsion was performed for 2 h, and afterward, detorsion was performed for 2 h. The rats were decapitated under ketamine anesthesia, and their testes tissues were removed. Tissue malondialdehyde, advanced oxidation protein products levels, eNOS expression, apoptosis and histopathological damage scores were then compared. Testicular torsion-detorsion caused significant increases in malondialdehyde level, apoptosis and eNOS expression level and caused a significant decrease in advanced oxidation protein product levels and testicular spermatogenesis in ipsilateral testes. GSPE prevented the rise in malondialdehyde, apoptosis and eNOS expression and improved testicular morphology and Johnsen's score. As a result, testicular torsion gives rise to serious damage in testes and GSPE is a potent antioxidant agent in preventing testicular injury.

Protective effects of melatonin against oxidative injury in rat testis induced by wireless (2.45 GHz) devices

Wireless devices have become part of everyday life and mostly located near reproductive organs while they are in use. The present study was designed to determine the possible protective effects of melatonin on oxidative stress-dependent testis injury induced by 2.45-GHz electromagnetic radiation (EMR). Thirty-two rats were equally divided into four different groups, namely cage control (A1), sham control (A2), 2.45-GHz EMR (B) and 2.45-GHz EMR+melatonin (C). Group B and C were exposed to 2.45-GHz EMR during 60minday(-1) for 30days. Lipid peroxidation levels were higher in Group B than in Group A1 and A2. Melatonin treatment prevented the increase in the lipid peroxidation induced by EMR. Also reduced glutathione (GSH) and glutathione peroxidase (GSH-Px) levels in Group D were higher than that of exposure group. Vitamin A and E concentrations decreased in exposure group, and melatonin prevented the decrease in vitamin E levels. In conclusion, wireless (2.45 GHz) EMR caused oxidative damage in testis by increasing the levels of lipid peroxidation and decreasing in vitamin A and E levels. Melatonin supplementation prevented oxidative damage induced by EMR and also supported the antioxidant redox system in the testis.

Postconditioning with far-infrared irradiation increases heme oxygenase-1 expression and protects against ischemia/reperfusion injury in rat testis

AimsStudies have shown that heme oxygenase-1 (HO-1) has a protective role in the mechanism underlying hypoxic preconditioning. We used a far-infrared radiation (FIR) heater to investigate the postconditioning protective role of HO-1 against ischemia/reperfusion (I/R) injury in rat testis. Main methodsForty rats were used. Testis ischemia was mimicked by total obstructive clamping of testis vessels for 1, 2, or 4h, and concomitant postconditioning with 30min FIR or heat light during initially 30min reperfusion. HO-1 expression and apoptosis of testis tissues were examined by immunohistochemistry and in situ terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay, respectively. HO-1 protein level and caspase-3 activity were analyzed by Western blotting. Key findingsThere was less apoptotic activity in rat testis after FIR, as determined by TUNEL assay. Higher HO-1 protein expression was observed by immunohistochemistry and Western blotting (p<0.01) in testis cells after FIR postconditioning. In contrast, caspase-3 activity was significantly higher in heat light groups, as compared with FIR groups (p<0.01). SignificanceFIR postconditioning attenuated I/R injury in rat testis by inducing HO-1 expression, which might have a protective role in testis apoptosis after I/R injury.

Honokiol Attenuates Torsion/Detorsion-induced Testicular Injury in Rat Testis by Way of Suppressing Endoplasmic Reticulum Stress-related Apoptosis

To investigate the protective effect of honokiol, a phytochemical used in traditional medicine, on testicular injury after torsion/detorsion (T/D) in a rat model. Testicular torsion is a medical emergency that can cause impairment of semen quality and permanent testicular atrophy or loss. Male Wistar rats were randomized to each time point of each group (n = 6/time point/group). After 2 hours of torsion, the testes were counter-rotated to the natural position. The rats in each group underwent a sham operation, T/D, or T/D with honokiol treatment (5 mg/kg and 10 mg/kg intraperitoneally, immediately before detorsion). Bilateral orchiectomy was performed at 6 and 24 hours and 3 months after detorsion. The testes were examined histologically. Apoptosis and endoplasmic reticulum stress were detected by Western blot. Histologic examination revealed that testicular T/D induced acute injury after 6 and 24 hours, and spermatogenesis was decreased at 3 months of follow-up. At 24 hours after T/D, increases were found in the activation of apoptosis-related molecules [poly (ADP-ribose) polymerase and caspases 3 and 7], and the expression levels of endoplasmic reticulum stress-associated molecules (phosphorylated-eukaryotic translation initiation factor 2 subunit α and CCAAT/enhancer-binding protein homologous protein). These increases were significantly reversed with honokiol treatment. Furthermore, honokiol effectively reversed the inhibition of spermatogenesis in testes treated with T/D for 3 months. The results of our study have shown that the endoplasmic reticulum stress-related apoptotic pathway is involved in testicular injury after testicular T/D. It remains to be determined whether alterations in this pathway would have a protective affect against reperfusion damage.

Ternatin pretreatment attenuates testicular injury induced by torsion/detorsion in Wistar rats

To investigate the possible protective role of the bioflavonoid ternatin (TTN) when administered before induction of ischemia/reperfusion injury in rat testis. Thirty-six Wistar rats were randomly assigned to 3 groups (n=12), divided in 2 subgroups (n=6). Saline 2.0ml (G-1), dimethylsulfoxide (DMSO) 3% solution (G-2) or TTN 12 mg/kg/dose (G-3) was administered ip. to all rats, respectively, 21, 12 and 1 hour before torsion. Anesthetized rats were subjected to ischemia (3 hours) induced by 720º torsion of the spermatic cord. Right testis and arterial blood samples were collected at the end of ischemia (T-0), and 3 hours later (T-3) for assessment of testis malonaldehyde (MDA), reduced glutathione (GSH), and plasma total antioxidant power (TAP). MDA decreased significantly (p<0,001) in G-2 and G-3 in T-0 and T-3 timepoints. Additional decrease in MDA was seen in G-3 after 3 hours of reperfusion (T-3). GSH increased significantly in G-2 (p<0.001) and G-3 (p<0.05) at the end the ischemia (T-0). A significant increase in GSH was seen 3 hours after testis detorsion (T-3) in G-2 rats. TAP values remained unchanged. The data provides in vivo evidence of the antiperoxidative and antioxidative properties of TTN in torted rat testis.

Dimethylsulfoxide attenuates ischemia-reperfusion injury in rat testis

To evaluate the protective role of dimethylsulfoxide (DMSO) in a rat model of testis ischemia/reperfusion (I/R). Twenty-four male Wistar rats were randomized in two equal groups. Control rats (G-1) received saline 2.0 ml intraperitoneally (ip) 21, 9 and 1 h before torsion. Experimental rats (G-2) received ip injections of 3% aqueous solution of DMSO, 0.1ml/10g body weight. Saline was added to complete 2.0ml when necessary. I/R injury was induced in anesthetized rats by torsion of the right testis lasting 3 hours. Testis and blood samples were collected at the end of ischemia (T-0) and 3 hours later (T-3) for assessment of testis malonaldehyde (MDA), reduced glutathione (GSH), and plasma total antioxidant power (TAP). MDA levels decreased significantly in G-2 rats compared with G-1 animals in all time-points. GSH levels increased significantly in T-0 and T-3 time-points in DMSO pretreated rats compared with G-1 rats. GSH levels increased significantly during reperfusion in G-2 rats. TAP was similar in both groups denoting absence of systemic effects in this study. Pretreatment with DMSO reduces testis lipid peroxidation and oxidative stress caused by torsion/detorsion of the testis.

Protective effect of curcumin in cisplatin-induced oxidative injury in rat testis: mitogen-activated protein kinase and nuclear factor-kappa B signaling pathways

The aim of this study was to investigate the cellular/biochemical mechanisms by which cisplatin (CIS) causes testicular toxicity. We evaluated the role of inducible nitric oxide synthase (iNOS) expression, mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-kB) activation in the pathogenesis of testicular damage induced by CIS, and investigated the effects of curcumin (CMN) against CIS-induced testicular injury in rats. Rats were divided into five equal groups: (1) control, (2) CIS, (3) CMN, (4) CIS + CMN and (5) CIS + corn oil. After the treatment, body and testicular weights, and plasma testosterone levels were observed, along with the biochemical, histopathological and immunohistochemical changes in testes. Testicular weight, plasma testosterone levels, activities of glutathione peroxidase (GSH-Px) and glutathione (GSH) levels significantly decreased, whereas the level of malondialdehyde (MDA) and nitric oxide (NO) significantly increased with CIS compared with the controls. A significant increase in plasma testosterone levels, GSH levels and GSH-Px activity, and a decrease in MDA and NO levels in testicular tissue were observed with CIS + CMN compared with that with CIS alone. There was marked staining for iNOS, MAPK/p38 and NF-kB/p65 expression with CIS compared with the control and CIS + CMN groups. CIS caused irregular seminiferous tubules, reduction of seminiferous epithelial layers, significant maturation arrest and perivascular fibrosis. CMN administration to CIS-treated rats significantly prevented these histopathologic changes. MAPK and NF-kB activation have a significant role in CIS-induced testicular toxicity. CMN has a strong potential for use as a therapeutic adjuvant in CIS gonadotoxicity.

The Evaluation Of The Role Of Hyperbaric Oxygen Therapy In Preventing The Ischemia-Reperfusion Injury Following Experimental Testicular Torsion

Testicular torsion is a urologic emergency where the injury is in form of ischemia-reperfusion and methods to lessen the morbidity should be used even after a successful detorsion procedure. In order to test the effect of hyperbaric oxygen therapy (HBO) treatment to reduce the testicular tissue damage and testicular function loss, we used rat testis models and compared the efficacy of a single session HBO treatment with repeated sessions. Young Sprague-Downey rats were used in this study and 4 experimental groups were instituted; 1) Sham: Testicles dissected, 2) Control: 720 degree torsion applied during 4 hours than detorsionned. 3) HBO-1: 4 hour torsion than one session HBO, and 4) HBO-7: 4-hour torsion than 7 sessions HBO. All testicles were removed one week later and germinal changes were evaluated. HBO treatment groups showed significantly high maturation rates when compared to the control group (p<0,05). Germinal epithelial necrosis was seen in all the rats of the control group. The rate of germinal epithelial necrosis was 1/9 in HBO-1 group and 6/9 in HBO-7 group. A decrease in the number of multinuclear bizarre cells and apoptotic cells was found significant only in HBO-1 group. HBO treatment was not found to have affected the number of seminiferous tubules having germinal cells with nuclear vacuolization. Although HBO treatment was found effective in preventing the damage from ischemia-reperfusion injury in rat testis; no significant difference was noted between a single and multiple sessions of HBO treatment.

Protective effect of dl-α-lipoic acid in cyclophosphamide induced oxidative injury in rat testis

The aim of the present study was to evaluate the protective effect of dl-α-lipoic acid on the biochemical changes, tissue peroxidative damage and abnormal antioxidant levels in the rat testis during cyclophosphamide (CP)-induced injury. Adult male Wistar rats were divided into four treatment groups: (I) control, (II) 15 mg/kg CP once a week for 10 weeks by gavage, (III) 35 mg/kg lipoic acid once a week for 10 weeks by intraperitoneal injection, and (IV) CP plus lipoic acid (24 h prior to CP administration). Testicular toxicity, assessed by decreased enzymatic activities of lactate dehydrogenase and glucose-6-phosphate dehydrogenase, was reversed with lipoic acid pretreatment. CP-exposed rats (group II) showed abnormal levels of enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione- S-transferase and glutathione reductase) and antioxidants (reduced glutathione, ascorbate and α-tocopherol) along with high malondialdehyde levels. In contrast, rats pretreated with lipoic acid (group IV) showed normal lipid peroxidation and antioxidant defenses. These findings indicate a cytoprotective role of lipoic acid in this experimental model of testicular toxicity.

Involvement of Lipid Peroxidation to the Early Stage of the Injury in Rat Testis Induced by Cadmium

To investigate when the changes of lipoperoxide contents in early stage of the inflammation are induced in the testis of rats after CdCl2 injection, we measured the lipoperoxide contents in plasma and tissues (liver, kidney and testis) at 1, 3, 5, 10, 15, 24 and 48 h after CdCl2 (5.0 mg/kg) injection. Lipoperoxide value in the testis increased significantly from 15 h after CdCl2 injection. Although no change of lipoperoxide value was observed in the liver through the experimental period, the value in the kidney increased significantly at 10 and 48 h after CdCl2 treatment. Heme protein value which represents the degree of hemorrhage in the testis also increased from 15 h after CdCl2 injection. This suggests that hemorrhage in the testis has a good correlation with an increase in lipid peroxidation in situ. The fact that significant increases in lipoperoxide values and in the degree of hemorrhage were observed from 15 h after CdCl2 injection, reveals the possibility that oxidative reactions occur in the testis of rats nearly 15 h after the treatment. Assay of enzyme activities in serum was performed simultaneously. The activity of β-glucuronidase which is considered to be one of parameters showing the occurrence of an inflammation, increased significantly at an early time (from 1 to 5 h) after CdCl2 treatment. This implies that some biochemical reactions occur in the testis before the time when the increase of lipoperoxide formation occurs. In the liver where no fluctuation of lipoperoxide concentration was observed during the experimental period, the Zn contents increased as the time elapsed after CdCl2 administration. On the contrary, a significant reduction of the Zn content was observed in the testis in which a considerable increase in lipoperoxide concentration was noticed, at 3-5 h after CdCl2 administration. The inflammation of testis by Cd is supposed to be initiated at this time stage. The difference of the Zn contents in these tissues may be considered to be one of factors which induce the difference among tissues in lipoperoxide concentration.

The role of radical oxygen in the mechanism of incidence of injury in rat testis administered CdCl2

It has been studied if radical oxygen involves in the formation of a hemorrhagic inflammation in the testis of rats intoxicated with CdCl2. H2O2 production in rats testis increased significantly at 24 hrs after CdCl2 injection (5.0 mg/kg) and it reached the highest value at 48 hrs. The curve of H2O2 production was very similar to that of heme protein contents in the testis with time course. Enzyme activities of catalase, glutathione peroxidase and glutathione reductase increased simultaneously, whereas superoxide dismutase activity was convertly depressed in the testis of intoxicated rats. On the other hand, in the liver where no inflammatory change manifested in the testis was observed, there was no increase of radical oxygen production and the activity of catalase rather decreased. These results indicate that CdCl2 administration increases the formation of radical oxygen, and it followed by the occurrence of tissue damage (lipid peroxidation and denaturalization of protein) . The difference in the occurrence of radical oxygen between liver and testis may have a significant meaning for interpreting the tissue difference against the injury of CdCl2.