Re-Protective Effects of Pre- and Post-Laparoscopy Conditioning, Zinc, Pentoxifylline, and N-acetylcysteine in an Animal Model of Laparoscopy-Induced Ischemia/Reperfusion Injury of the Kidney

Zn2+ improves sepsis-induced acute kidney injury by upregulating SIRT7-mediated Parkin acetylation

Zn2+ levels are reported to be correlated with kidney function. We explored the significance of Zn2+ in sepsis-induced acute kidney injury (SI-AKI) through the regulation of sirtuin 7 (SIRT7) activity. The sepsis rat model was established by cecal ligation and perforation (CLP) and intraperitoneally injected with ZnSO4 or SIRT7 inhibitor 97491 (SIRT7i), with renal tubular injury assessed by hematoxylin and eosin staining. In vitro, human renal tubular epithelial cells (HK-2) were induced with lipopolysaccharide to obtain a renal injury cell model, followed by ZnSO4 or SIRT7i and autophagy inhibitor (3-methyladenine) treatment. Interleukin (IL)-1β, IL-18, reactive oxygen species (ROS), Parkin acetylation level, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) expression levels were determined. The renal tubule injury, inflammation condition, and pyroptosis-related and autophagy-related protein levels were assessed. The pyroptosis in kidney tissues and autophagosome formation were observed by transmission electron microscopy. Zn2+ alleviated renal injury in CLP rats and inhibited pyroptosis and its related protein levels by inhibiting SIRT7 activity in septic rat renal tissues. In vitro, Zn2+ increased HK-2 cell viability and reduced KIM-1, NGAL, IL-1β, IL-18, NLRP3 inflammasome, cleaved caspase-1, gasdermin D-N levels, and pyroptotic cell number. Zn2+ increased autophagosome number and LC3BII/LC3BI ratio and decreased TOM20, TIM23, P62, and mitochondrial ROS levels. Zn2+ increased Parkin acetylation by repressing SIRT7 activity. Inhibiting mitophagy partially averted Zn2+-inhibited NLRP3 inflammasome activation and apoptosis in HK-2 cells. Zn2+ upregulated Parkin acetylation by repressing SIRT7 activity to promote mitophagy and inhibit NLRP3 inflammasome activation and pyroptosis, thus improving SI-AKI.NEW & NOTEWORTHY Zn2+ upregulated Parkin acetylation by repressing sirtuin 7 activity to promote mitophagy and inhibit NLRP3 inflammasome activation and pyroptosis, thus improving sepsis-induced acute kidney injury.

Renoprotective effects of zinc sulfate against transient liver ischemia/reperfusion injury in rats

Objectives

Liver ischemia/reperfusion damage frequently occurs in setting of hepatic resection and liver transplantation. It leads to disturbance in remote organs such as heart, lung and kidneys. This study explored the consequences of hepatic ischemia/reperfusion on the oxidative stress parameters, biochemical factors, and histopathological alterations in the kidney's rats, as well as evaluated the role of zinc sulfate on above-mentioned parameters.

Materials and methods

Twenty-eight male Wistar rats were accidently assigned into four groups (n = 7). They were Sham, ischemia/reperfusion, zinc sulfate pretreatment, and zinc sulfate pretreatment + ischemia/reperfusion groups. Sham group: obtained normal saline (2 ml/day, seven consecutive days), intraperitoneally, zinc sulfate pretreatment group: obtained zinc sulfate (5 mg/kg, seven consecutive days, intraperitoneally). Ischemia/reperfusion group: obtained normal saline as mentioned previous, then rats experienced the partial ischemia (%70) for 45 min followed by 60 min reperfusion. Zinc sulfate pretreatment group: obtained zinc sulfate as mentioned previous, then rats experience the partial ischemia/reperfusion as presented earlier. At the end of investigation, blood was withdrawn, liver and renal tissues were removed. Then, biochemical and oxidative stress parameters, and histological changes were evaluated in the mentioned tissues.

Results

The findings of this experiment indicated that zinc sulfate markedly reduced the serum levels of liver and kidney function tests in relative to ischemia/reperfusion group. Also, antioxidant enzymes activity, ferric reducing antioxidant power, and nitric oxide significantly increased, while malondialdehyde level declined in the renal tissue of zinc sulfate + ischemia/reperfusion group compared to ischemia/reperfusion rats. Furthermore, zinc sulfate alleviated the liver and kidneys histopathological alterations following ischemia/reperfusion.

Conclusion

Zinc sulfate ameliorated liver and kidney function, and improved oxidant-antioxidant balance in favor of antioxidants. It is suggested that zinc sulfate may be beneficial effects on hepato-renal injury after ischemia/reperfusion.

Mediators of Regional Kidney Perfusion during Surgical Pneumo-Peritoneum Creation and the Risk of Acute Kidney Injury—A Review of Basic Physiology

Acute kidney injury (AKI), especially if recurring, represents a risk factor for future chronic kidney disease. In intensive care units, increased intra-abdominal pressure is well-recognized as a significant contributor to AKI. However, the importance of transiently increased intra-abdominal pressures procedures is less commonly appreciated during laparoscopic surgery, the use of which has rapidly increased over the last few decades. Unlike the well-known autoregulation of the renal cortical circulation, medulla perfusion is modulated via partially independent regulatory mechanisms and strongly impacted by changes in venous and lymphatic pressures. In our review paper, we will provide a comprehensive overview of this evolving topic, covering a broad range from basic pathophysiology up to and including current clinical relevance and examples. Key regulators of oxidative stress such as ischemia-reperfusion injury, the activation of inflammatory response and humoral changes interacting with procedural pneumo-peritoneum formation and AKI risk will be recounted. Moreover, we present an in-depth review of the interaction of pneumo-peritoneum formation with general anesthetic agents and animal models of congestive heart failure. A better understanding of the relationship between pneumo-peritoneum formation and renal perfusion will support basic and clinical research, leading to improved clinical care and collaboration among specialists.

Role of Zinc Supplementation on Ischemia/Reperfusion Injury in Various Organs

Ischemia-reperfusion (I/R) injury is a serious condition which is associated with myocardial infarction, stroke, acute kidney injury, trauma, circulatory arrest, sickle cell disease, and sleep apnea and can lead to high morbidity and mortality. Salts of zinc (Zn) are commonly used by humans and have protective effects against gastric, renal, hepatic, muscle, myocardial, or neuronal ischemic injury. The present review evaluates molecular mechanisms underlying the protective effects of Zn supplement against I/R injury. Data of this review have been collected from the scientific articles published in databases such as Science Direct, Scopus, PubMed, and Scientific Information Database from 1991 to 2019. Zn supplementation increased the decreased parameters including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione (GSH), metallothionein (MT), protein sulfhydryl (P-SH), and nuclear factor-erythroid 2-related factor-2 (Nrf2) expression and decreased the increased elements such as endoplasmic reticulum (ER) stress, mitochondrial permeability transition pore (mPTP) opening, malondialdehyde (MDA), serum level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and microRNAs-(122 and 34a), apoptotic factors, and histopathological changes. Zn also increases phosphatidylinositol 3-kinase (PI3K)/Akt and glycogen synthase kinase-3β (GSK-3β) phosphorylation and preserves protein kinase C isoforms. It is suggested that Zn can be administered before elective surgeries for prevention of side effects of I/R injury.

The effect of laparoscopy on mast cell degranulation and mesothelium thickness in rats

Background

Laparoscopy induces adhesion due to ischemia-reperfusion injury. However, the detail pathomechanism is poorly understood. This study aimed to investigate the impact of laparoscopy on mast cell and mesothelium morphological changes in the rat.

Methods

Forty-nine males of Sprague-Dawley Rattus norvegicus were divided into four groups: a) control and b) intervention groups P1, P2, and P3 that underwent 60 min laparoscopic using carbon dioxide (CO₂) insufflation at 8, 10, and 12 mmHg groups, respectively. Serum hydrogen peroxide (H₂O₂), catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), and oxidative stress index (OSI) levels were determined 24 h after laparoscopy. Histopathological analyses of mast cell infiltration and degranulation and mesothelium thickness in the liver, greater omentum, mesenterium, small intestine, and peritoneum were performed 7 days after the procedure.

Results

H₂O₂, MDA, and OSI levels were significantly increased in the intervention groups compared with the control (p<0.05), while the SOD and CAT levels were decreased in the intervention groups compared with the control (p<0.05). Mast cell infiltration and degranulation were higher in the intervention groups than in control (p<0.05), while the mesothelium thickness was significantly lower in the laparoscopic groups than in control (p<0.05). Interestingly, the decrease in mesothelium thickness was strongly associated with the increase in mast cell infiltration and degranulation (p<0.01).

Conclusions

Our study shows that laparoscopy in rats increases mast cell infiltration and degranulation, which also results in and correlates with a decrease in mesothelial thickness.

Protective effects of postconditioning in transvaginally created pneumoperitoneum

There are reports of ischemic complications in clinical practice after laparoscopy using pneumoperitoneum. Conditioning has a beneficial effect for various ischemic diseases. This experimental study was designed to evaluate the effects of postconditioning in transvaginally created pneumoperitoneum. Sixty adult female rats, weighing 300±50 g were divided into four equal groups. Pneumoperitoneum was created by CO₂ insufflation under a pressure of 10 mmHg. Rats in the first group (sham) were subjected to only sham-operation or gas insufflation. The second group (TV/PP) was subjected to pneumoperitoneum for 60 min followed by 30 min of desufflation. The third group (post-5) was subjected to pneumoperitoneum for 60 min followed by 5 min of desufflation, 5 min of insufflation and again followed by 30 min of desufflation. The fourth group (post-2.5) was subjected to pneumoperitoneum for 60 min followed by 2.5 min of desufflation and 2.5 min of insufflation-repeated in two cycles- and then followed by 30 min of desufflation. The rats were sacrificed, and blood was collected after 30 min, 2 and 6 h from the last desufflation. Levels of oxidative stress markers, malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione (GSH), sulfhydryl groups (SH) and inflammatory cytokine TNF-α, were analyzed. Levels of MDA in the post-5 group were significantly reduced compared to the TV/PP and post-2.5 groups. The level of GSH in TV/PP animals was markedly reduced compared to the Sham, Post-5 and Post-2.5 groups. In addition, levels of SH were increased in the Post-5 group in comparison to the Sham, TV/PP and Post-2.5 groups. No difference in the activity of SOD between the groups was found, and the concentration of TNF-α in TV/PP animals was significantly higher than that in the Sham and postconditioning groups. Overall, the results of the present study indicate that postconditioning can reduce pneumoperitoneum-induced oxidative injury.

Protective Effect of Zinc Supplementation on Renal Ischemia/Reperfusion Injury in Rat: Gender-related Difference

Background:

Zinc (Zn) knows as essential microelement which prevents oxidative stress. The effect of Zn supplement on renal function parameters in rats subjected to renal ischemia-reperfusion (IR) injury was investigated.

Methods:

Male and female rats were subjected to renal IR with and without Zn sulfate (10 mg/kg/day for 5 days) supplementation. The kidney function markers and histology findings in Zn-treated group were compared with sham and control groups.

Results:

The serum levels of blood urea nitrogen and creatinine (Cr) and kidney tissue damage score were increased significantly after renal injury (P < 0.05) gender dependently, but no alterations were observed for these markers in Zn-treated animals after renal IR injury. Cr clearance was significantly different between genders (P < 0.05); however, Zn supplementation increased the Cr clearance and kidney nitrite level significantly in male rats (P < 0.05). Zn also increased urine flow in female (P < 0.05), but it did not alter urine load of Na (U_NaV) and percentage of Na excretion (E_Na%).

Conclusions:

Zn may improve renal function after IR injury gender dependently.

The Effect of Zinc Sulfate on miR-122, miR-34a, Atioxidants, Biochemical and Histopathological Parameters Following Hepatic Ischemia/Reperfusion Injury in Rats

Liver ischemia-reperfusion (IR) injury is a situation which occurs in various conditions such as pringle maneuver and liver transplantation. The regulatory effect of zinc sulfate (ZnSO4) is an important trace element on several liver disorders well known, but its effects on microRNA_S (miR-122 and miR-34a) have not been evaluated. The goal of this study was to identify the protective effects of ZnSO4 on IR-induced liver injury, in particular, microRNA_S in rats. Thirty-two male Wistar rats were randomly assigned into four groups (eight each group): sham, IR, ZnSO4 pretreatment, and ZnSO4 + IR groups. In sham and ZnSO4 pretreatment groups, animals received normal saline (N/S, 2 ml/kg) and ZnSO4 (5 mg/kg) for 7 consecutive days intraperitoneally (ip), then only laparotomy was performed. In IR and ZnSO4 + IR groups, N/S and ZnSO4, respectively, were given with the same dose, time, and route, before induction of ischemia for 45 min followed by reperfusion for 60 min. Blood sample was taken for biochemical and microRNAs analysis. Tissue specimens also were obtained for the measurements of antioxidant activities and histopathological evaluations. Our results showed that ZnSO4 pretreatment ameliorated histopathological changes decreased the increased serum levels of liver enzymes, miR-122 and miR-34a, and enhanced the decreased activity of antioxidant enzymes following hepatic IR injury. The present study indicated that ZnSO4 had potential hepatoprotective action against IR-induced injury. Therefore, it has been suggested that it can be administered as an anti-miR before elective hepatic surgeries for prevention of this complication.

Effects of propofol on the inflammatory response during robot-assisted laparoscopic radical prostatectomy: a prospective randomized controlled study

Robot-assisted laparoscopic radical prostatectomy (RALRP) is a minimally invasive procedure; however, some amount of surgical trauma that can trigger systemic inflammation remains. Moreover, pneumoperitoneum during RALRP induces ischemia–reperfusion injury (IRI). Propofol, an anesthetic, is known to have anti-inflammatory and antioxidant properties. In the present study, we compared the effects of propofol with those of desflurane on inflammation and IRI during RALRP via measurements of different biomarkers and evaluation of perioperative renal function. Fifty patients were randomized to receive either desflurane (n = 25) or propofol (n = 25) with remifentanil during RALRP. Serum levels of interleukin (IL)-6 (IL-6), tumor necrosis factor alpha, C-reactive protein, and nitric oxide were measured 10 min after anesthesia induction (T1), 100 min after carbon dioxide (CO₂) insufflation (T2), and 10 min after CO₂ deflation (T3). Perioperative urine outputs and the serum creatinine level at 24 h after surgery were also recorded. We found that IL-6 levels at T2 and T3 were higher than those at T1 in both groups, although the increases were significant attenuated only in the propofol group. The other parameters showed no differences among the three time points in both groups. The intraoperative urine output was significantly higher in the propofol group than in the desflurane group, while the creatinine level showed no significant changes in either group. Our findings suggest that propofol can not only attenuate the inflammatory response during and after pneumoperitoneum in patients undergoing RALRP but also prevent oliguria during pneumoperitoneum.

High-pressure carbon dioxide pneumoperitoneum induces oxidative stress and mitochondria-associated apoptotic pathway in rabbit kidneys with severe hydronephrosis

The primary aim of the present study was to investigate the potential effect of high‑pressure carbon dioxide (CO2) pneumoperitoneum on kidneys with severe hydronephrosis and to investigate the possible underlying mechanism. A total of 18 rabbits underwent a surgical procedure inducing severe hydronephrosis. Rabbits were then divided at random into three groups (n=6 each) and subjected to intraabdominal pressure of 0, 8 or 18 mmHg, respectively. CO2 inflation lasted for 90 min in the pneumoperitoneum groups. Oxidative stress was assessed by measurements of reactive oxygen species (ROS). Activation of apoptosis was analyzed by western blot analysis of B‑cell lymphoma 2 (Bcl‑2), Bcl‑2‑associated x protein (Bax), cytochrome c (Cyt c), caspase‑3 and caspase‑9 levels. In addition, TUNEL assay, hematoxylin and eosin (H&E) staining, measurement of mitochondrial membrane potential (MMP) and detection of changes to kidney ultramicrostructure were performed. In the 0 and 8 mmHg groups, all results were normal and similar. However, in the 18 mmHg group, the kidneys suffered oxidative damage and mitochondrial injuries, and increased ROS levels, lower MMP and mitochondrial vacuolization were observed. Furthermore, the mitochondrial/caspase‑dependent pathway of apoptosis was activated, as indicated by the apoptotic index, and the expression levels and translocation of Bax, Bcl‑2, Cyt c, caspase‑3 and caspase‑9. Therefore, it is concluded that high‑pressure CO2 pneumoperitoneum induces oxidative damage and apoptosis in rabbit kidneys with severe hydronephrosis, which is associated with the mitochondrial apoptotic pathway.

Zinc mitigates renal ischemia-reperfusion injury in rats by modulating oxidative stress, endoplasmic reticulum stress, and autophagy

Oxidative stress is a major factor involved in the pathogenesis of renal ischemia/reperfusion (I/R). Exogenous zinc (Zn) was suggested as a potent antioxidant; however, the mechanism by which it strengthens the organ resistance against the effects of reactive oxygen species (ROS) is not yet investigated. The present study aims to determine whether acute zinc chloride (ZnCl₂ ) administration could attenuate endoplasmic reticulum (ER) stress, autophagy, and inflammation after renal I/R. Rats were subjected to either sham operation (Sham group, n = 6), or 1 hr of bilateral ischemia followed by 2 hr of reperfusion (I/R groups, n = 6), or they received ZnCl₂ orally 24 hr and 30 min before ischemia (ZnCl₂ group, n = 6). Rats were subjected to 1 hr of bilateral renal ischemia followed by 2 hr of reperfusion (I/R group, n = 6). Our results showed that ZnCl₂ enhances renal function and reduces cytolysis (p < 0,05). In addition, it increased significantly the activities of antioxidant enzymes (SOD, CAT, and GPX) and the level of GSH in comparison to I/R (p < 0,05). Interestingly, ZnCl₂ treatment resulted in significant decreased ER stress, as reflected by GRP78, ATF-6,p-eIF-2α, XPB-1, and CHOP downregulaion. Rats undergoing ZnCl₂ treatment demonstrated a low expression of autophagy parameters (Beclin-1 and LAMP-2), which was correlated with low induction of apoptosis (caspase-9, caspase-3, and p-JNK), and reduction of inflammation (IL-1ß, IL-6, and MCP-1) (p < 0,05). In conclusion, we demonstrated the potential effect of Zn supplementation to modulate ER pathway and autophagic process after I/R.

Effects of dexpanthenol and N-acetylcysteine pretreatment in rats before renal ischemia/reperfusion injury

BACKGROUND

We investigated the anti-inflammatory and protective effects of concomitant use of dexpanthenol (DXP) and N-acetylcysteine (NAC) induced ischemia/reperfusion (I/R) injury of kidney.

METHODS

Forty rats were randomly divided into 5 groups. In all groups except for Group 1(Sham), renal arteries bilaterally occluded with vascular clamp for IR injury. Group 1(Sham), received a single dose of 10 mL/kg isotonic saline daily by intraperitoneal (IP) injection for three days. Group 2(IR), received a single dose of 10 mL/kg isotonic saline daily by IP injection for three days. Group 3(IR + NAC), received 300 mg/kg NAC daily by IP injection for three days. Group 4(IR + DXP), received 500 mg/kg DXP daily by IP injection for three days. Group 5(IR + NAC + DXP), received 500 mg/kg DXP and 300 mg/kg NAC daily by IP injection for three days. Serum urea (BUN), creatinine (Cr) and neutrophil gelatinase-associated lipocalin (NGAL, lipocalin 2, siderocalin) levels were measured as kidney function tests. TNF-α levels were measured as inflammatory marker. Tissue sections were evaluated histopathologically under light microscopy.

RESULTS

IR + NAC + DXP group received both NAC and DXP before induction of renal I/R and as the biochemical and histopathological data revealed the results of the IR + NAC + DXP group and sham group were similar. Biochemically and histopathologically, combined use of NAC and DXP has better results when each of them used alone.

CONCLUSION

We concluded that concomitant use of DXP and NAC plays a major role against I/R injury and may be useful in acute treatment of I/R induced renal failure.

The effect of dexmedetomidine on oxidative stress during pneumoperitoneum

Purpose. This study was intended to investigate the effect of dexmedetomidine on oxidative stress response in pneumoperitoneum established in rats. Methods. Animals were randomized into three groups, group S: with no pneumoperitoneum, group P: with pneumoperitoneum established, and group D: given 100 mcg intraperitoneal dexmedetomidine 30 min before establishment of pneumoperitoneum. Plasma total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) activity were measured 30 min after conclusion of pneumoperitoneum. Results. The mean TOS level was significantly higher in group P than in the other two groups, and the TOS level was significantly higher in group D than in group S (P < 0.05). Plasma TAS level was found to be lower in group P than in the other two groups, and the TAS level was lower in group D than in group S (P < 0.05). Consequently, the OSI was significantly higher in group P than in groups D and S (P < 0.05). Conclusions. Ischemia-reperfusion phenomenon that occurs during pneumoperitoneum causes oxidative stress and consumption of plasma antioxidants. Dexmedetomidine decreases oxidative stress caused by pneumoperitoneum and strengthens the antioxidant defense system.

Protective effects of dexmedetomidine in pneumoperitoneum-related ischaemia-reperfusion injury in rat ovarian tissue

OBJECTIVES

To determine the effects of dexmedetomidine on pneuomoperitoneum-related ischaemia-reperfusion (I/R) injury in rat ovarian tissue.

STUDY DESIGN

Animals were randomized into three groups: Group S (n=8), no pneumoperitoneum; Group C (n=8), pneumoperitoneum; and Group D (n=8), 100μg intraperitoneal dexmedetomidine 30min before pneumoperitoneum. Ovarian tissue was collected from all rats 30min after desufflation, and fresh frozen for histological and biochemical evaluation.

RESULTS

Body weight was similar in all three groups (202.62±28.86, 211.00±14.45 and 212.87±15.71g in Groups S, D and C, respectively). The mean malondialdehyde level was higher in Group C than the other groups (p<0.03). When the histological samples of ovarian tissue were compared, vascular congestion, haemorrhage, follicular cell degeneration and infiltrative cell infiltration scores were higher in Group C compared with the other groups (p<0.05). Significantly lower scores for the histological parameters were found in Group D compared with Group C (p<0.05). Similar scores for follicular cell degeneration and inflammatory cell infiltration were found in Group D and Group S (p>0.05). Although vascular congestion and haemorrhage scores were significantly lower compared with Group C, higher scores were found for Group D compared with Group S (p<0.05).

CONCLUSION

Pneumoperitoneum caused oxidative injury in rat ovarian tissue. Dexmedetomidine reduced oxidative stress and histological injury related to I/R.

Pharmacological modulation of oxidative stress response in minimally invasive surgery: systematic review

This systematic review aims to synthesize the data on the effectiveness of pharmacological modulation of stress response in minimally invasive surgery. Eligible trials were clinical trials randomized or not or experimental trials that investigated the effect of pharmacological agents on modulation of surgical stress response to minimally invasive surgery. No clinical trials were identified. Eight experimental trials met the inclusion criteria and were obtained in full text. Experimental models were rats or rabbits subjected to pneumoperitoneum, or pneumoretroperitoneum, not to a whole operation. Pharmacological modulation of surgical stress response was attempted with erythromycin, melatonin, mesna, verapamil, pentoxifylline, N-acetylcysteine, and zinc. All the pharmacological agents, except pentoxifylline, seemed to reduce oxidative stress markers. However, only mesna pretreatment prevented oxidative stress, because oxidative stress markers remained in the sham levels. Contrasting data were obtained for pentoxyphilline. In conclusion, available data suggest that pharmacological modulation of surgical stress response to minimally invasive surgery might be feasible.

Pretreatment with pentoxifylline and N-acetylcysteine in liver ischemia reperfusion-induced renal injury

BACKGROUND AND AIMS

Acute hepatic injury causes systematic inflammatory responses which may finally lead to functional disturbances in remote organs. In this study, the effects of an inhibitor of inflammatory cytokines (pentoxifylline, PTX) and a well-known antioxidant, N-acetylcysteine (NAC), were evaluated on renal damage and oxidative stress following liver ischemia reperfusion (IR).

METHOD

Five groups of six male rats were used. Group 1 was sham operated. In group 2, 90 min liver partial ischemia was induced by a clamp around both hepatic artery and portal vein and then followed by 4 h of reperfusion. In groups 3 and 4, PTX or NAC was injected intraperitoneally before the ischemia, while in group 5 both drugs were co-administered. The levels of alanine amino-transferase (ALT), aspartate amino-transferase (AST), blood urea nitrogen (BUN), and creatinine in serum as well as malonyldialdehyde (MDA) and glutathione (GSH) levels and morphological changes in renal tissues were assessed.

RESULTS

Significant increase in the serum levels of ALT and AST in IR group is indicative of liver functional damages. Elevated BUN and renal tissue MDA, decreased GSH levels, and morphological damages in IR group demonstrate a significant kidney injury and oxidative stress comparing to sham group. Administration of PTX alone and PTX + NAC prevented the IR-induced increase in renal MDA levels. Administration of both drugs and their co-administration prevented the reduction in renal GSH levels and morphological changes.

CONCLUSION

Pretreatment with PTX and NAC before liver IR may be useful to ameliorate renal oxidative damage by preservation of cellular GSH concentration and a reduction in MDA levels.

N-acetylcysteine (NAC) protects against acute kidney injury (AKI) following prolonged pneumoperitoneum in the rat

BACKGROUND

Acute kidney injury (AKI) following prolonged laparoscopy is a documented phenomenon. Carbon dioxide pneumoperitoneum induces oxidative stress. Previous experimental studies have shown that the antioxidant, N-acetylcysteine, protects the rat from AKI following ischemia-reperfusion. The aim of this study was to evaluate the effects of N-acetylcysteine (NAC) on rat renal function after prolonged pneumoperitoneum.

METHODS

Normal rats treated or not with NAC were submitted to abdominal CO(2) insufflation of 10 mmHg, at short and long periods of time of 1 and 3 h, respectively, and evaluated at 24, 72 h, and 1 wk after deinsufflation. Glomerular filtration rate (GFR) was measured by inulin clearance and oxidative stress was evaluated by serum thiobarbituric acid reactive substances (TBARS) RESULTS: No significant alterations in GFR were observed in normal animals submitted to the pneumoperitoneum of 1 h and evaluated after 24 h desufflation. With 3 h of pneumoperitoneum, a significant and progressive decrease in GFR occurred 24 and 72 h after desufflation with an increase in serum TBARS. GFR returned to normal levels a week later. In the NAC-treated rats, a complete protection against GFR drops was observed 24 and 72 h following 3 h of pneumoperitoneum associated with a decrease in TBARS.

CONCLUSION

These results suggest that NAC protects against acute kidney injury following prolonged pneumoperitoneum. These findings have significant clinical implications.

Warming and humidification have no effect on oxidative stress during pneumoperitoneum in rats

Pneumoperitoneum is reported to induce oxidative stress due to the desiccative effect of cold, dry gas insufflation. The aim of this study is to compare the effect of warmed, humidified insufflation to standard gas, by measuring oxidative stress markers in a physiologically relevant animal model. Twenty male Wistar rats (330?650 g) were alternately assigned to the Warm Humidified group (WH, n = 10) and Control group (n = 10). All rats underwent pneumoperitoneum at 5 mmHg and a controlled flow rate for 110 min. The WH group received warmed (37?C) and humidified (98% Relative Humidity (RH)) gas and the control group received standard gas at room temperature (19?C) and 0% RH. At the end of pneumoperitoneum, samples of liver, kidney, pancreas, jejunum, and lung were excised. Levels of plasma and tissue malondialdehyde (MDA) and protein carbonyls (PC) were measured. Organ light microscopy was performed. There were no differences between groups for MDA or PC concentrations in plasma, liver, kidney, jejunum, or lung tissue. There were no differences in histological score between groups. Warming and humidification of pneumoperitoneum insufflation gas have no effect on measures of oxidative stress compared to non-warmed, non-humidified controls.