Stress In Renal Tissues Research Articles

The oxidative effect of prolonged CO2 pneumoperitoneum on renal tissue of rats

Despite its advantages, laparoscopic donor nephrectomy is associated with prolonged operation time, which could potentially increase oxidative stress in the graft. We performed the first experimental, randomized, controlled study with blind assessment of outcome to address this possibility. Wistar-Albino rats were randomized into three groups. The animals in the control group were subjected to a sham operation under anesthesia; the animals in the other two groups were subjected to CO(2) pneumoperitoneum (Pp) for 120 and 240 min, respectively. The kidneys were removed at the end of each experiment. The concentrations of protein carbonyl and sulfhydryl (SH) groups and the activities of superoxide dismutase (SOD) were measured in renal tissue samples as markers of oxidative stress. Renal tissue samples were also evaluated histopathologically using light microscopy. Exposure to 120 min of Pp significantly increased the finding of oxidative stress in renal tissue samples, with an increase in protein carbonyl content and a decrease in protein sulfhydryls and tissue (SOD) activities. When exposure to Pp was prolonged from 120 min to 240 min, Pp associated oxidative stress was found to be increased. These changes occurred in the absence of light microscopical evidence of overt tissue damage. In an experimental model resembling laparoscopic donor nephrectomy, we found that exposure of pneumoperitoneum prolonged from 120 min to 240 min acts as an additive factor with respect to causing increased oxidative stress in renal tissue. Because these effects imply subtle tissue injury that may contribute to the chronic demise of renal grafts obtained laparoscopically, avoiding the use of Pp if possible and keeping operation time less than 120 min during laparoscopic donor nephrectomy appear to be advisable.

The effect of verapamil on the prevention of ischemia/reperfusion injury in the experimental retroperitoneoscopic donor nephrectomy model.

This study investigated the effect of intravenous administration of verapamil in prevention of the injury caused by free oxygen radicals generated in a rabbit retroperitoneoscopic donor nephrectomy model. Twenty-four adult New Zealand rabbits were divided into four groups. In group I, balloon dissection of the left retroperitoneal space was performed. In group II, CO2 at 10 mmHg was applied for 3 hours after the balloon dissection. In group III, laparotomy was performed, the left renal pedicle was clamped for 3 min, and the clamp was removed 5 min before nephrectomy. In group IV, 2 min before the attempt 0.2 mg/kg verapamil was given intravenously, and the same procedure was employed as in group III. Nephrectomy was performed after each experiment. The concentrations of malonyl dialdehyde (MDA), reduced glutathione (GSH), and protein carbonyl content were measured in renal tissue samples as markers of oxidative stress. Pneumoretroperitoneum (Prp) promoted oxidative stress in renal tissues, with an increase of MDA and protein carbonyl content. The verapamil- pretreated group (group IV) showed statistical significantly lower values of MDA and protein carbonyl content when compared with group II and III (p < 0.05), whereas tissue GSH concentrations were unchanged in all groups. Our study showed that Prp causes increased oxidative stress in renal tissue. Warm ischemia lasting 3 min did not exert an additive effect on Prp-associated oxidative stress. Verapamil reduces the oxidative stress markers caused by Prp.

Changes in tissue-oxidative stress markers in an experimental model of laparoscopic donor nephrectomy.

Laparoscopic donor nephrectomy (LDN) is associated with prolonged warm ischemia, which could potentially increase oxidative stress in the graft. Because pneumoperitoneum (Pp) used to facilitate LDN impairs renal perfusion, it could augment the effects of warm ischemia. Our experimental, randomized, controlled study with blind outcome assessment is the first to address this possibility. Wistar-Albino rats were randomized to 4 groups. Controls were subjected to a sham operation; the remainder were subjected to Pp with or without warm ischemia of differing durations. The kidneys were removed at the end of each experiment. The concentrations of malondialdehyde (MDA), protein carbonyl, and sulfhydryl groups and the activities of superoxide dismutase (SOD) and catalase were measured in renal samples as markers of oxidative stress. Renal samples were also evaluated histopathologically using light microscopy. Pp promoted oxidative stress in renal tissues, with an increase of MDA and protein carbonyls and a decrease in protein sulfhydryls and SOD activity. Warm ischemia exerted an additive effect on Pp-associated oxidative stress only when sustained for 10 minutes. These changes occurred in the absence of light-microscopic evidence of overt tissue damage. In an experimental model resembling LDN, Pp and 10 minutes of warm ischemia emerged as additive factors with respect to causing increased oxidative stress in the kidney. Because these effects imply subtle injury not only in the harvested kidneys of live donors but also in the kidneys the donors retain, avoiding Pp and warm ischemia above 5 minutes during LDN appears advisable.

Changes in tissue-oxidative stress markers in an experimental model of laparoscopic donor nephrectomy

Background. Laparoscopic donor nephrectomy (LDN) is associated with prolonged warm ischemia, which could potentially increase oxidative stress in the graft. Because pneumoperitoneum (Pp) used to facilitate LDN impairs renal perfusion, it could augment the effects of warm ischemia. Our experimental, randomized, controlled study with blind outcome assessment is the first to address this possibility. Methods. Wistar-Albino rats were randomized to 4 groups. Controls were subjected to a sham operation; the remainder were subjected to Pp with or without warm ischemia of differing durations. The kidneys were removed at the end of each experiment. The concentrations of malondialdehyde (MDA), protein carbonyl, and sulfhydryl groups and the activities of superoxide dismutase (SOD) and catalase were measured in renal samples as markers of oxidative stress. Renal samples were also evaluated histopathologically using light microscopy. Results. Pp promoted oxidative stress in renal tissues, with an increase of MDA and protein carbonyls and a decrease in protein sulfhydryls and SOD activity. Warm ischemia exerted an additive effect on Pp-associated oxidative stress only when sustained for 10 minutes. These changes occurred in the absence of light-microscopic evidence of overt tissue damage. Conclusion. In an experimental model resembling LDN, Pp and 10 minutes of warm ischemia emerged as additive factors with respect to causing increased oxidative stress in the kidney. Because these effects imply subtle injury not only in the harvested kidneys of live donors but also in the kidneys the donors retain, avoiding Pp and warm ischemia above 5 minutes during LDN appears advisable.