Zinc Supplementation and Ischemia Pre-conditioning in Renal Ischemia/ Reperfusion Injury

@#Backgrounds: Renal ischemia/reperfusion (RIR) is a major cause of kidney dysfunction in clinic. The main objective of this study was to investigate the effect of pre-conditioning ischemia (IPC) and zinc (Zn) supplementation on renal RIR injury. Methods: A total of 63 unilateral nephrectomised male and female Wistar rats were divided into five groups. Group 1 (ShOPR): Rats as sham-operated group were subjected to surgical procedure without RIR. Group 2 (Isch): Rats underwent RIR (left kidney ischemia for 30 min followed by 48 h reperfusion). Group 3 (Zn+Isch): Rats were treated as group 2 but they received Zn sulphate (30 mg/kg) 1 h before induction of RIR. Group 4 (IPC+Isch): Rats were treated as group 2 but they underwent 1 min of ischemia followed by 3 min reperfusion as IPC, which was repeated for three times before induction of RIR. Group 5 (Zn+IPC+Isch): Rats were subjected to receive both Zn sulphate and IPC before induction of RIR. Urine samples were collected in the last 6 h of reperfusion, and finally biochemical and histological measurements were performed. Results: The serum level of creatinine (Cr), normalised kidney weight (KW) and kidney tissue damage score (KTDS) increased by RIR alone significantly (P < 0.05). These parameters were attenuated statistically by Zn supplementation (P < 0.05). However, IPC alone or cotreatment of Zn and IPC did not improve the biochemical and histological markers altered by RIR injury. Conclusion: Zn supplementation had a protective role against RIR while such protective effect was not observed by IPC alone or by co-treatment of Zn and IPC.

Role of angiotensin type 2 receptor on nitric oxide production response to angiotensin II administration in ovariectomised rats treated with estradiol

Renin-angiotensin system activity is gender related. The vasodilatory response of angiotensin II [AngII] angiotensin type 2 receptor [AT2R] may involve nitric oxide [NO] production. We attempted to find the role of AT2R on NO formation response to AngII administration in ovariectomised rats treated with estradiol [OVE]. A total of 33 female Wistar rats were divided into 3 groups; intact animals, ovariectomised treated with placebo [OVX] and OVE. At 2 weeks later, all animals were subjected to anesthetize and catheterize and each group was divided into two subgroups that received AT2R antagonist [PD123319] or vehicle. Each animal was subjected to 1 h continuous infusion of AngII [20 miceog/kg/h] and the level of NO metabolite [nitrite] was measured before and after AngII infusion. At the presence of AT2R, the serum level of nitrite in response to AngII administration in OVE groups increased significantly [P < 0.05]. However, this increase was abolished by AT2R antagonist. It seems that AT2R involves nitrite production response to AngII in OVE

Ameliorative effect of melatonin against contrast media induced renal tubular cell injury

Reactive oxygen species [ROS] is a mediator of renal damage. Melatonin is a potent-free radical scavenger. Our objective was to test whether melatonin would protect against the nephrotoxicity of contrast media. In an experimental study 40 adult male Wistar rats were randomly divided into four equal groups including: 1] Control group [No drug], 2] Contrast media group [10 ml/kg iodixanol i.v. single dose], 3] Contrast media and melatonin [first 10 ml/kg iodixanol then 10 ml/kg/day melatonin by i.p. injection on days 3, 4 and 5] and 4] Contrast media and melatonin pretreatment group [melatonin 10 ml/ kg/day by i.p. injection on 1, 2 and 3 days, then 10 ml/kg iodixanol by i.v. injection on third day. The blood creatinine and BUN as well as the histological changes were evaluated for severity of renal injury [degeneration, vacuolization of tubular renal cells, dilatation of tubular lumen and presence of debris in the lumens], by scoring from one to four. Contrast media significantly increased the creatinine and BUN and renal injury [p < 0.05]. Melatonin prevented and reversed the injury induced by contrast media [P < 0.05]. Pretreatment with melatonin reduced the renal injury induced by contrast media [P < 0.05]. Melatonin is an effective drug to prevent contrast-induced renal injury. Therefore its usage [especially pretreatment] might be beneficial in patients who are planning to use contrast media agents

Lack of nephroprotective efficacy of althaea officinalis flower extract against gentamicin renal toxicity in male rats

Gentamicin [GM] is used as antibiotic for Gram-negative infections, but its administration is limited due to a side-effect of nephrotoxicity. It was attempted to investigate the effect of Althaea officinalisflower extract [AOFE] against nephrotoxicity induced by GM in male rats. 30-year-old male Wistar rats were divided into five groups. Group 1 as a negative control group received AOFE 250 mg/kg/day. Groups 2-5 received saline, AOFE 50 mg/kg/day, AOFE 250 mg/kg/day, and AOFE 500 mg/kg/day for 9 days, respectively, and GM [100 mg/kg/day] was added from the 3rd day on. At the end of the experiment, blood samples were obtained, animals were sacrificed, and the kidneys were removed immediately. Gentamicin [in group 2] significantly increased serum levels of blood urea nitrogen and creatinine as well as the pathological damage score [P < 0.05] when compared with group 1. Low dose of AOFE did not decrease the nephrotoxicity induced by GM while the high dose of AOFE aggravated renal toxicity [P < 0.05]. Although AOFE acts as an antioxidant, at the doses used in the current study did not ameliorate nephrotoxicity induced by GM

Pomegranate flower extract does not prevent cisplatin-induced nephrotoxicity in female rats

Nephrotoxicity is the major side-effect of cisplatin [CDDP], and it is reported to be gender-related. We evaluated the effects of pomegranate flower extract [PFE] as an antioxidant on CDDP-induced nephrotoxicity in female rats. Twenty-three adult female rats in four groups treated as following. Groups 1 and 2 received PFE at doses of 25 and 50 [mg/kg/day], respectively, for 9 days, and from day 3 on, they also received cisplatin [CDDP] [2.5 mg/kg] daily. Group 3 was treated as group 1 expects saline instead of PFE, and group 4 received PFE [25 mg/kg/day] alone. Cisplatin alone increased the serum levels of blood urea nitrogen, creatinine, and nitrite; and kidney tissue damage score and kidney weight. However, PFE not only did not ameliorate the induced nephrotoxicity, but also aggravated renal tissue damage. Pomegranate extract as an antioxidant did not ameliorate CDDP-induced nephrotoxicity in female rats

Co-administration of silymarin and deferoxamine against kidney, liver and heart iron deposition in male iron overload rat model

Tissue iron deposition may disturb functions of the organs. In many diseases like thalassemia, the patients suffer from iron deposition in kidney and heart tissues. Deferoxamine [DF] is a synthetic iron chelator and silymarin [SM] is an antioxidant and also a candidate for iron chelating. This study was designed to investigate the effect of DF and SM combination against kidney and heart iron deposition in an iron overload rat model. Male Wistar rats were randomly assigned to 5 groups. The iron overloading was performed by iron dextran 100 mg/kg/day every other day during 2 weeks and in the 3[rd] week, iron dextran was discontinued and the animals were treated daily with combination of SM [200 mg/kg/day, i.p.] and DF [50 mg/kg/day, i.p.] [group 1], SM [group 2], DF [group 3] and saline [group 4]. Group 5 received saline during the experiment. Finally, blood samples were obtained and kidney, heart and liver were immediately removed and prepared for histopathological procedures. The results indicated no significant difference in kidney function and endothelial function biomarkers between the groups. However, combination of SM and DF did not attenuate the iron deposition in the kidney, liver and heart. DF alone, rather than DF and SM combination, significantly reduced the serum level of malondialdehyde [P < 0.05]. Co-administration of SM and DF significantly increased the serum level of ferritin [P <0.05]. DF and SM may be potentially considered as iron chelators. However, combination of these two agents did not provide a protective effect against kidney, liver and heart iron deposition

Protective role of recombinant human erythropoietin in kidney and lung injury following renal bilateral ischemia-reperfusion in rat model

Acute kidney injury [AKI] has been recognized as one of the most complex clinical complications in modern medicine, and ischemia/reperfusion [I/R] injury is well-known as a main reason of AKI. In addition, AKI leads to important systemic consequences such as acute lung injury. This study was designed to investigate the role of erythropoietin [EPO] on kidney function makers and tissue damage; and lung endothelial permeability and lung water content [LWC] in bilateral renal I/R injury model in rats. Male Wistar rats were randomly divided into three groups of sham, I/R, and I/R treated with EPO [I/R + EPO] groups. The I/R and I/R + EPO groups were subjected to bilateral renal I/R injury; however, only the I/R + EPO group received EPO [500 IU/kg, i.p.] 2 h before ischemia surgery, and the same dose was continued once a day for 3 days after ischemia. The sham group underwent a surgical procedure without ischemia process. The blood urea nitrogen [BUN] and serum creatinine [Cr] levels, kidney tissue damage score [KTDS], and kidney weight [KW] per 100 g body weight significantly increased in I/R group [P < 0.05]. EPO administration decreased levels of BUN and Cr significantly [P < 0.05], and KTDS and KW insignificantly [P = 0.1]. No significant differences in kidney and serum levels of malondialdehyde, and lung vascular permeability and LWC were observed between the groups. The serum and kidney levels of nitrite were not significantly different between I/R and sham groups; however, administration of EPO increased the renal level of nitrite [P < 0.05]. EPO protected the kidney against I/R injury; however, it may not protect the lung tissue from the damage induced by renal I/R injury in rats

N-acetylcysteine prevents kidney and lung disturbances in renal ischemia/ reperfusion injury in rat

One of the most common causes of acute kidney injury [AKI] is kidney ischemia/reperfusion injury [IRI]. The distant organ injury such as acute lung injury is one of the side effects of AKI or kidney IRI. In this study, we performed bilateral renal IRI in rats and the protective role of N acetylcysteine [NAC] in kidney and lung was investigated. Rats [n = 30] were randomly assigned to four experiment groups. The group 1 was assigned as sham operated group. Before kidney IRI performance, the others groups were treated with saline [group 2], 150 mg/kg [group 3] or 500 mg/kg [group 4] of NAC, and the treatment were continued daily after IRI for next 3 days. At day 3, the all groups' animals were subjected for the measurements. The serum level of blood urea nitrogen [BUN] and creatinine [Cr] in the control group increased significantly [P < 0.05], and administration of NAC [150 mg/kg] decreased the serum levels of Cr and BUN. However, only the serum level of Cr decreased significantly [P < 0.05]. NAC did not improve kidney weight and damage; however, its low dose [150 mg/kg] attenuated the lung injury score [P < 0.05] when compared with the control group. No significant differences were observed in lung water content and endothelial permeability, serum levels of malondialdehyde and nitrite between the groups. Low dose of NAC as a protectant agent may protect the kidney function and lung tissue damage after kidney IRI

Efficacy of co-administration of garlic extract and metformin for prevention of gentamycine-renal toxicity in wistar rats: a biochemical study

Gentamicin [GM] nephrotoxicity has been related to oxidative stress. Garlic and metformin [MF] have anti-oxadant activity and therefore, this study was aimed to evaluate the preventive and curative effects of garlic, MF and their combination on GM indeced tubular toxicity in Wistar rats. In a pre-clinical study, 70 male Wistar rats were randomly designated into 7 groups of 10 and treated as follows: Group 1: Received saline for 20 days. Group 2: Were injected 100 mg/kg/d of GM intraperitoneally [ip], for 10 days and saline for 10 more days. Group 3: Received GM for 10 days then 20 mg/kg garlic ip for the next 10 days. Group 4: Received GM for 10 days and MF [100 mg/kg] orally for the next 10 days. Group 5: Received GM for 10 days and a combination of MF and garlic for the next 10 days [100 and 20 mg/kg, respectively]. Group 6: The same as group 5but with half-doses of MF and Garlic. Group 7: Received GM for 10 days together with a combination ofMF and garlic. On 20th day of the experiment the serum blood urea nitrogen [BUN] and creatinine [Cr] were measured and compared in different groups. GM injection significantly increased the serum BUN and Cr [P < 0.05]. Administration of MF, garlic or their combination with or after injection of GM [high doses] could atenuate BUN and Cr. The results indicate that MF and garlic or their combination have curative and protective activity against GM nephrotoxicity

Protective role of silymarin and deferoxamine against iron dextran-induced renal iron deposition in male rats

Kidney iron deposition [KID] is caused by iron overload that is observed in kidney diseases and anemia. The protective effects of deferoxamine [DF] and silymarin [SM] were studied against iron overload-induced KID in rat model. Rats received iron dextran [200 mg/kg] for a period of 4 weeks every other day, but at the beginning of week 3, they also were subjected to a 2-week [every other day] treatment with vehicle [group 2, positive control], SM [200 mg/kg; group 3], DF [50 mg/kg; group 4], SM [400 mg/kg; group 5], and combination of SM and DF [200 and 50 mg/kg, respectively; group 6]. Group 1, as the negative control, received saline alone during the study. The levels of serum creatinine [Cr], blood urea nitrogen [BUN], iron, ferritin, and nitrite were determined, and the kidney was removed for histopathological investigations. Before treatment, the serum levels of iron and ferritin in all iron dextran receiver groups were significantly higher than those of the negative control group [P < 0.05]. However, the serum levels of BUN, Cr, and nitrite were not different between the groups. No statistical differences were detected in kidney weight and the serum levels of BUN, Cr, iron, ferritin, and nitrite after 2 weeks of treatment with SM, DF, or combination of both. The SM and DF treatments reduced the intensity of the KID, but only in the SM [200 mg/kg] group, a significant reduction in KID was observed [P < 0.05]. It seems that SM is a nephroprotectant agent against KID in acute iron overload animal models

Angiotensin 1-7 receptor and angiotensin II receptor 2 blockades prevent the increased serum and kidney nitric oxide levels in response to angiotensin II administration: Ggender-related difference

The angiotensin II [Ang II] receptor 2 [AT2R] and angiotensin 1-7 receptor [masR] expression in the kidney are gender-related. We attempted to compare the response of nitric oxide [NO] production to Ang II administration, with and without AT2R and masR blockades, using A-779 and PD123319 in male and female rats. Anesthetized and catheterized male and female Wistar rats were subjected to one-hour continuous infusion of Ang II [tilde20 microg/kg/hour], with and without masR and AT2R blockades. The level of the NO metabolite [nitrite] was measured before and after the experiment in rat serum and in the homogenized kidney tissue. The basal data indicated that no sex difference in the serum level of nitrite could be detected before Ang II infusion. However, administration of Ang II in male and female rats caused a gender difference in the nitrite level, which resulted in the serum level of the nitrite significantly increasing in males [P < 0.05] when compared with the females. In addition, masR blockade or co-blockade of masR and AT2R in male rats abolished the gender difference related to the effect of Ang II on nitrite production. In the presence of masR and AT2R, or when masR alone was blocked, the level of nitrite in the kidney, in response to the Ang II infusion was not significantly different between the two sexes. On the contrary, masR and AT2R co-blockades significantly decreased the kidney nitrite concentration response to Ang II administration in both male and female rats [P < 0.05], but no sex difference was detected. The renal vasculature of male rats may provide more response to Ang II administration-induced NO, which is dependent on masR and AT2R. During dual masR + AT2R blockades, the kidney NO formation wasreduced in a non-gender related manner

Preventive and curative effects of ginger extract against histopathologic changes of gentamicin-induced tubular toxicity in rats

Gentamicin [GM] is a commonly used aminoglycoside, however, renal toxicity has limited its usage. This study was designed to evaluate the curative and protective effects of Zingiber officinale [ginger] against gentamicin tubular toxicity in rats. The phenolic and flavonoid components and antioxidant activity of ginger were also evaluated. In a preclinical study, 50 male Wistar rats were designated into 5 groups of 10 and treated as follows: Group I: vehicle. Group II: 200 mg/kg/d of ginger for 3 days then, GM [80 mg/kg] for 7 days. Group III: 200 mg/kg ginger orally for 3 days, then ginger plus GM for 7 days. Group IV: GM for 7 days. Group V: GM for 10 days. Group VI: GM for 7 days, then 200 mg/kg ginger orally for 10 days. At the end of the study, the animals were sacrificed and their kidneys were histologically evaluated. Ginger could prevent degeneration of the renal cells and reduce the severity of tubular damage caused by gentamicin. However, it could not regenerate the GM degeneration. The results indicate that ginger is effective as a prophylaxis agent, but has not curative effect

Serum and peritoneal fluid levels of vascular endothelial growth factor in women with endometriosis

Endometriosis is known as one of the most common disease in women of reproductive age. Due to important role of vascular endothelial growth factor [VEGF] in neo-vascularization for the implantation of endometrial cell, and also presence of different studies reported VEGF level in the serum and peritoneal fluid [PF] in endometriosis patients, this study was designed to determine the serum and PF levels of VEGF in endometriosis patients, and to compare with normal subjects. In this descriptive study, 179 women subjected to laparoscopy for the evaluation of infertility or pelvic pain were allocated into the following two groups: group I: different types of endometriosis patients [n=90] and group II: non-endometriosis patients [n=89]. The PF from pelvis and venous blood samples were obtained. The VEGF concentration of the serum and PF were measured using enzyme immunoassay kit and were compared using t test. The level of VEGF in serum was significantly less than that in PF in both groups [p=0.00]. However, endometriosis patients had significantly higher level of VEGF in peritoneal fluid than non-endometriosis patients [p=0.043]. According to our findings, endometriosis is not associated with change in the level of circulating VEGF

C-reactive protein of serum and peritoneal fluid in endometriosis

Endometriosis is defined as the existence of endometrial-like tissue outside the uterus. Diagnosis of endometriosis is a challenging theme. Despite the broad search for innovative laboratory tests and advances in imaging technologies, there are still no easy, non-invasive diagnostic tests available. Due to inflammatory process of endometriosis, still C-reactive protein [CRP] level may be the target of initial screening. The aim of this study was to investigate CRP levels as a marker of inflammatory process in serum and peritoneal fluid of patients with endometriosis. In a case control study, 179 patients with endometriosis [N = 90] and without endometriosis [N = 89] were evaluated. The venous blood samples were obtained from all patients before laparoscopy and the peritoneal fluid samples were collected from pelvis before any manipulation. Student's t-test was applied to compare the parameters between two groups. There was no significant difference between the CRP serum level in patients with endometriosis and infertile women without endometriosis. There was a significant difference in peritoneal level of CRP between case and control groups [p < 0.05]. The findings suggested that measurement of this marker in patients' serum or plasma cannot be used to diagnose endometriosis. It is further recommended that a combination of different markers might be helpful in this regard that could be studied in future

role of magnesium supplementation in cisplatin-induced nephrotoxicity in a rat model: no nephroprotectant effect

Cisplatin [CP] is used as the commonest drug to treat solid tumors. It is accompanied by a nephrotoxicity side effect. The main objective of this study is to investigate the protective role of magnesium [Mg] supplementation in CP-induced nephrotoxicity in a rat model. Twenty-nine Wistar rats were randomly assigned to four groups [1-4]. Groups 1-3 received 20, 80, and 200 mg/kg magnesium sulfate respectively, for 10 days, but on day 3, a single dose of CP [7 mg/kg, i.p.] was also injected. Group 4 [positive control group] received the same regimen of Groups 1-3 except saline instead magnesium sulfate. One week after CP administration, blood samples were obtained and all animals were killed for kidney histopathological investigations. All CP-treated animals lost weight, and the percentage of weight loss in Group 1 [low dose Mg sulfate treated] was significantly higher compared with the positive control group [Group 4, P < 0.05]. The increase in blood urea nitrogen [BUN] and creatinine [Cr] levels in serum in Group 1 were more than those in other groups [P < 0.05]. No statistical differences were observed in serum magnesium, nitrite, and total protein levels among the groups. The kidney tissue damage in Groups 1-3 was not significantly different when compared with Group 4. Moreover, the kidney and testis weights in Group 1 were significantly greater than those in the positive control group [P < 0.05]. Regarding the BUN and Cr levels in the serum, kidneys weight, and the histopathological study, the low dose of Mg supplementation intensifies kidney toxicity and renal dysfunction in CP-induced nephrotoxicity in the rat model. However, the protective role of Mg with moderate and high doses is not certain

effect of aspirin on serum vascular endothelial growth factor and nitric oxide concentration in high-cholesterol fed rabbits

Hypercholesterolemia is one of the major risk factors for atherosclerosis which is characterized by endothelial dysfunction. This study was designed to investigate the effect of aspirin on serum vascular endothelial growth factor [VEGF] and nitric oxide [NO] concentrations in hypercholesterolemic animals. Sixteen male rabbits were randomly divided into two groups, aspirin-treated and control. Aspirin [10 mg/kg/day] was administered orally using feeding tube. All animals were fed with high-cholesterol diet [1%] during the experiment. After five weeks, blood pressure, serum lipid and lipoprotein profiles, serum VEGF and NO concentrations were measured. Aspirin did not change blood pressure. Aspirin significantly decreased serum LDL [1276 +/- 72.1 vs. 1505 +/- 68.03 mg/dl] and triglyceride [477.5 +/- 8.3 vs. 649.1 +/- 15.2 mg/dl] [P<0.05]. High-cholesterol diet significantly decreased serum VEGF level in both groups [control: 24.59 +/- 0.42 vs. 38.09 +/- 2.49 pg/ml; aspirin: 24.72 +/- 0.84 vs. 42.29 +/- 2.03 pg/ml] [P<0.05] and aspirin did not change serum VEGF level in hypercholesterolemic animals [P>0.05]. Serum NO concentration was also significantly decreased after five weeks of high-cholesterol diet [control: 5.87 +/- 0.33 vs. 8.67 +/- 0.68 ?mol/lit; aspirin: 5.66 +/- 0.33 vs. 8.58 +/- 0.60 ?mol/lit] [P<0.05]. Aspirin did not change serum NO level [P>0.05]. We conclude that under the conditions of this study, aspirin cannot change serum VEGF and NO concentrations in high-cholesterol fed animals

Mathematical model for determination of colloid osmotic pressure: the role of albumin-globulin ratio

Colloid Osmotic Pressure [COP] is an important factor in the fluid balance of body compartments. COP is related to Total Protein [TP] concentration and Albumin: Globulin Ratio [A/G]. The A/G was not included in pervious empirical models, and therefore the main objective of this study was to develop a mathematical model to determine the COP in terms of TP concentration and A/G. Sera with different A/G were prepared in-vitro, and COP was measured directly using colloid osmometer. The relationship between COP, TP concentration and A/G were determined mathematically. The validity of developed empirical models was confirmed by statistical comparison between measured and calculated COP in 122 serum samples obtained from hospitalized patients and healthy individuals. By non-linear regression, the following relationships were found between COP, TP concentration and A/G. All coefficients were statistically significant [p<0.05]: COP = [4.0814 A/G TP]/[A/G + 0.0153 TP]; r[2] = 0. 91272. COP = [5.3192 A/G -2.2252 [A/G]2 + 0.2939 [A/G]3] TP; r[2] = 0.94737 No significant differences were indicated between measured COP and calculated one in clinical data. The variation of A/G may be the most effective factor for the differences between calculated and measured COP. This parameter must be considered when the direct measurement of COP is unavailable

effect of estrogen on endothelial permeability of aorta and the level of serum nitrite concentration in cholesterol-fed ovariectomized rabbit

Estrogen Replacement Therapy [ERT] in postmenopausal women may decrease the risk of Coronary Artery Diseases [CAD]. We hypothesized that Nitric Oxide [NO] releasing due to ERT may be the essential factor by which endothelial permeability decreases. Four groups of ovariectomized rabbits were under investigation for five weeks. Groups 1 and 4 received high cholesterol diet and other two groups [2 and 3] had normal diet. Estradiol valerate [5 mg] was injected weekly in groups 1 and 2. Blood samples were taken before and after the experiment. Finally, the animals were sacrificed for endothelial permeability determination and pathological investigation of aortae. After five weeks, the total cholesterol, triglycerides, HDL and LDL were significantly different between high cholesterol fed and normal diet groups [P<0.05]. In cholesterol-fed groups, triglycerides concentration was also different significantly [P<0.05]. Nitrite concentration was increased significantly in group 1, and it was different from other groups [P<0.05]. A considerable decrease of aorta permeability was obtained in group 1 but it was not significantly different from group 4 [P<0.1]. The considerable existence of fatty streaks was observed in the animals aortae of group 4, and it was significantly different from group 1 [P<0.05]. It suggests that prevention of intimal collection of foam cells and fatty streak in aorta by estrogen may be exerted by NO production