Effects of moderate intensity training and lithium on spatial learning and memory in a rat model: The role of SIRT3 and PGC1-α expression levels and brain-derived neurotropic factor

In this study we investigated the potential synergistic effects of moderate interval training (MIT) and lithium on spatial learning and memory. Forty-two male Wistar males were classified into six groups including I: Control, II: 10 mg/kg/day IP lithium (Li10), III: MIT, IV: Li10 + MIT, V: 40 mg/kg/day IP lithium (Li40), and VI: Li40 + MIT. Then, the rats underwent Morris Water Maze (MWM) test to assess their spatial memory and learning ability. Brain-derived neurotrophic factor (BDNF) density was measured by enzyme-linked immunosorbent assay (ELISA), and the expression of PGC1 and SIRT3 were assessed via qRT-PCR. The results show that MIT improves both memory and spatial learning; but lithium alone, does not cause this. Additionally, those exposed to a combination of exercise and lithium also had improved spatial learning and memory. Finally, we observed a positive role of BDNF protein, and PGC1 gene on the effects of exercise and lithium.

Anesthesia and analgesia for common research models of adult mice

Anesthesia and analgesia are major components of many interventional studies on laboratory animals. However, various studies have shown improper reporting or use of anesthetics/analgesics in research proposals and published articles. In many cases, it seems "anesthesia" and "analgesia" are used interchangeably, while they are referring to two different concepts. Not only this is an unethical practice, but also it may be one of the reasons for the proven suboptimal quality of many animal researches. This is a widespread problem among investigations on various species of animals. However, it could be imagined that it may be more prevalent for the most common species of laboratory animals, such as the laboratory mice. In this review, proper anesthetic/analgesic methods for routine procedures on laboratory mice are discussed. We considered the available literature and critically reviewed their anesthetic/analgesic methods. Detailed dosing and pharmacological information for the relevant drugs are provided and some of the drugs' side effects are discussed. This paper provides the necessary data for an informed choice of anesthetic/analgesic methods in some routine procedures on laboratory mice.

Eugenol Administration Improves Liver Damage Induced by a Fructose-Rich Diet

Backgrounds:

The prevalence of metabolic syndrome (MetS) is increasing in developing countries that affects the liver in a variety of ways. This study was designed to investigate the protective role of eugenol on liver damage caused by fructose-induced MetS.

Materials and Methods:

Thirty male Wistar rats were randomly divided into five groups: 1: tap water (control), 2: fructose, 3: fructose + eugenol solvent, 4: fructose + eugenol 50 mg/kg, and 5: fructose + eugenol 100 mg/kg. At the end of the experiment, blood samples were taken for measurement fast blood glucose (FBG), serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic pyruvate transaminase (SGPT), low-density lipoprotein, high-density lipoprotein, cholesterol, and triglyceride.

Results:

FBG significantly increased in Group 2 compared to Group 1 (P < 0.001); however, it significantly decreased in Groups 4 and 5 compared to Group 2 (P < 0.05). SGOT and SGPT levels significantly increased in Group 2 compared to the control group (P < 0.001). However, SGOT and SGPT levels significantly decreased in Groups 4 and 5. Malondialdehyde (MDA) and liver tissue damage score (LTDS) significantly increased in Group 2 compared with the control group (P < 0.01), whereas MDA and LTDS decreased in Groups 4 and 5 compared to Group 2 (P < 0.05).

Conclusion:

Eugenol may ameliorate liver damage in a rat model of fructose-induced MetS, and these protective effects may in part be mediated by improving antioxidant status and reducing oxidative stress and lipid peroxidation. It may also reduce hepatic inflammation and fat accumulation as well as fibrosis of liver cells.

The Effect of Influenza Vaccination on COVID-19 Morbidity, Severity and Mortality: Systematic Review and Meta-Analysis

Coronavirus disease 2019 (COVID-19) pandemic is rapidly developing worldwide with a high mortality rate. In this meta-analysis study, the effect of influenza vaccination on the prevention of COVID-19 and its consequences in patients were investigated. The systematic search for this study was performed from November 2019 to 25 November 2020, in the databases of Medline, PubMed, Scopus, Web of Science, Embase, Ebsco, Cochrane and medRxiv. Search terms used included COVID-19, coronavirus, SARS-CoV-2, covid, influenza, flu, grippe and vaccine. The present study examined the association between influenza vaccination and COVID-19 including COVID-19 infection, mortality, hospitalisation and intensive care unit (ICU) admission. Finally, the pooled estimates for different outcomes were calculated by the software for statistics and data science (STATA) version 15 and I2 was used to determine the heterogeneity. By analysing the data of articles, the pooled estimates of these data indicated that influenza vaccination could lower probability of COVID-19 infection up to 24% (OR = 0.77; 95% CI: 0.65, 0.91), of death up to 32% (OR = 0.68; 95% CI: 0.42, 1.11), of the hospitalisation up to 25% (OR = 0.75; 95% CI: 0.46; 1.23) and of admission to ICU up to 29% (OR = 0.71; 95% CI: 0.40, 1.27). Influenza vaccination can help decrease the COVID-19 infection and reduce hospitalisation and the need for ICU and mortality rates.

Gastrointestinal and renal complications in SARS-CoV-2-infected patients: Role of immune system

The recent severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) disease has been accompanied by various gastrointestinal (GI) and renal manifestations in significant portion of infected patients. Beside studies on the respiratory complications of coronavirus infection, understanding the essential immunological processes underlying the different clinical manifestations of virus infection is crucial for the identification and development of effective therapies. In addition to the respiratory tract, the digestive and urinary systems are the major sources of virus transmission. Thus, knowledge about the invasion mechanisms of SARS‐CoV‐2 in these systems and the immune system responses is important for implementing the infection prevention strategies. This article presents an overview of the gut and renal complications in SARS‐CoV‐2 infection. We focus on how SARS‐CoV‐2 interacts with the immune system and the consequent contribution of immune system, gut, and renal dysfunctions in the development of disease.

The protective effects of eugenol on metabolic-syndrome, renal damages

Introduction: Metabolic syndrome consists of a group of abnormities which is involved with chronic kidney disease and nephropathy. Eugenol is an important phenolic component, which is present in many plants’ essential oils such as cloves oil with antioxidant effects. Objectives: Our study planned to demonstrate eugenol’s effects over nephrotoxicity derived from metabolic syndrome. Materials and Methods: Thirty-five male Wistar rats were picked accidentally and then divided into five groups including 1) tap water; 2) water with fructose10%; 3) water with fructose + sweet almond oil and administered intraperitoneally; 4) water with fructose+ eugenol 50 mg/kg/d and administered intraperitoneally; 5) water with fructose+ eugenol 100 mg/kg/d administered intraperitoneally. This regime lasted for 60 days, and at the beginning of day 31st, injections started for 30 days. Assessment of serum, urine and renal parameters (in homogenized kidney tissue) were conducted in the last step. Results: The results argued that the induction of metabolic syndrome following renal injury has significantly increased serum blood urea nitrogen (BUN) and creatinine (Cr) levels in the fructose group. Consumption of eugenol resulted in a significant reduction in the level of these two biochemical factors (P < 0.05). The renal level of malondialdehyde (MDA) increased in the fructose group while treatment with a dose of 50 eugenol decreasing its level (P < 0.05). Proteinuria and kidney tissue damage score (KTDS) increased in the fructose group compared with the tap water group (P < 0.001). It is noteworthy that treatment with eugenol did not affect the level of proteinuria and KTDS with any of the used doses. Conclusion: Our results indicated the improvement of renal functioning and decrease in lipid peroxidation, although eugenol doses used in this study did not reduce proteinuria and KTDS.

Angiotensin-converting Enzyme 2 roles in the Pathogenesis of COVID-19

The new pandemic Coronavirus Disease 2019 (COVID-19) causes a wide range of clinical consequences, from asymptomatic infection to acute respiratory failure and it is very heterogeneous. The renin-angiotensin system (RAS) is well recognized as a key regulating system in circulatory homeostasis that play prominent roles in pathophysiological processes in abnormal activation for instance renal and cardiovascular diseases, obesity, and stroke. Angiotensin converting enzyme 2(ACE2) as a component of the RAS system. However, unlike the ACE, its activity is not inhibited by the ACE inhibitors. The major product of ACE2 is Ang1-7, known as a vasodilator peptide and part of the depressant arm of the RAS. There are two form of ACE2. Coronavirus cover with some proteins in order to help viral attachment to the cell membrane ACE2 as a receptor and then fuse and enter the cells. ACE2 was expressed in oral Cavity, salivary glands of the mouth, esophagus, myocardial cells, kidney, and enterocytes, along all the respiratory tract, intestine, and blood vessels. In this article, we explain the renin-angiotensin system and its components. Also, we shortly explain the organs involved in COVID-19 disease and we will talk about the possible causes of damage to these organs. We also reviewed the probable mechanism of using ACE2 in viral attachment and the probable treatment processes will also be discussed based on the surface proteins of the virus and ACE2. In addition, we briefly discuss the anti-angiotensin drugs and why patients with chronic disease are more susceptible to COVID-19 infection and show worse progression.

Gastrointestinal and kidney manifestations in SARS-CoV and SARS-CoV-2 infections: role of angiotensin-converting enzyme 2

The emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in 2020, which has a substantial structural similarity to severe acute respiratory syndrome coronavirus (SARS-CoV) that caused the outbreak in 2003, is currently a threat to global health. Lung involvement is the principal clinical feature in infected patients but extra-pulmonary clinical presentations are also common. The reasons for the extensive involvement of other organs are not yet clear. Angiotensin-converting enzyme 2 (ACE2), the key peptide of renin–angiotensin system (RAS), has recently identified as a major receptor for the both SARS-CoV and SARS-CoV-2 that might be a main target of coronavirus infection. ACE2 is mainly expressed in the pulmonary pneumocytes, the small intestine enterocytes as well as the proximal tubule epithelial cells of the kidneys. In addition to the respiratory tract infection symptoms, the noticeable prevalence of gastrointestinal symptoms as well as kidney impairment in hospitalized infected patients highlights other routes of infection/transmission. In present review, we discussed the role of RAS with emphasis on ACE2 in the pathogenesis of SARS-CoV and SARS-CoV-2, particularly in gastrointestinal and kidney manifestations of the diseases.

Does exercise training attenuate cisplatin nephrotoxicity?

Cisplatin (CP), a medication originating from the platinum has been used for solid cancers’ treatment in the last decade. CP is associated with numerous side effects as well. One of the side effects is nephrotoxicity. There are some types of procedure which can attenuate harmful effects of the drug, and the effectiveness of physical activity has been a controversial topic. It is well established that physical activity has positive effects on chronic kidney disease (CKD). The exercise training can modulate CP induced muscle wasting both in males and females. Although exercise training may have protective effect on renal function and the related risk factors, it cannot attenuate the renal injury resulted from CP therapy in females. The exercise training may improve interleukin 6 and heme oxygenase-1, reduces the production of CD4+T cell cytokines from the kidney, which play a major role in adaptive immune response. The present mini-review considered the effect of exercise training accompanied by the CP treatment.

Simultaneous use of oxalate-degrading bacteria and herbal extract to reduce the urinary oxalate in a rat model: A new strategy

Objective:

Urinary stones with oxalate composition can cause kidney failure. Recent findings evidenced that probiotics are effective in reducing oxalate absorption in these subjects based on their high colonic absorption levels at baseline. The purpose of this study was to evaluate the effect of the simultaneous use of oxalate-degrading bacteria, Urtica dioica and T. terrestris extract in reducing urinary oxalate.

Materials and Methods:

Anti-urolithiatic activity of Urtica dioica and T. terrestris extract and probiotic by using ethylene glycol induced rat model. In this study, 4 strains of Lactobacillus and 2 strains of Bifidobacterium and also 2 strains of L. paracasei (that showed high power in oxalate degrading in culture media) were used. Male Wistar rats were divided into four groups (n=6). The rats of group-I received normal diet (positive control group) and groups-II (negative control group), III, IV rats received diet containing ethylene glycol (3%) for 30 days. Groups III rats received Urtica dioica and T. terrestris extract. Groups IV rats received extracts + probiotic for 30 days.

Findings:

The results show that the use of herbal extracts (Urtica dioica and T. terrestris) reduced the level of urinary oxalate and other parameters of urine and serum. Also, the accumulation of calcium oxalate crystals in the kidney tissue was significantly reduced.

Conclusion:

Considering that the formation of calcium oxalate crystals can cause inflammation and tissue damage in the kidney, the use of herbal extracts with oxalate degrading bacteria can be a new therapeutic approach to preventing the formation of kidney stones.

Interaction of Sex Hormones and the Renin-Angiotensin System in Ovariectomized Rats Subjected to Ischemia-Reperfusion Induction

Backgrounds:

Ischemia-reperfusion (IR) injuries occur in a variety of clinical conditions, which lead to kidney damage. Most of the tissue damages after IR are due to the activation of the renin–angiotensin system (RAS). Hence, in this study, the interaction of sex hormones and RAS in ovariectomized (OV) rats subjected to IR induction has been studied.

Materials and Methods:

The animals were divided into different groups. Groups 1 (OV + E, OV rat + estradiol) and 2 (OV rat) each one consisted of three separate IR-induced subgroups treated with losartan, angiotensin 1–7 (Ang 1–7), and their combination, Group 3, as control and Group 4, as sham. Next, 72 h after IR, blood samples were collected, the right kidneys were homogenized, and left kidneys were fixed in 10% formalin.

Results:

Findings show that serum blood urea nitrogen, creatinine, and kidney tissue damage score levels increased significantly with induction of IR (P < 0.05). Mean serum levels of these factors in OV + E groups are higher than those of the OV. The presence or absence of estradiol did not affect the levels of antioxidants in the different groups receiving Los, Ang 1–7, and their combination. Los, Ang 1–7, and their combination reduced serum and kidney malondialdehyde levels in both OV and OV + E groups.

Conclusion:

Estrogen not only fails to improve renal functioning but it can also exacerbate it. While the treatments used in this study, in the absence of estradiol, it had a better effect on kidney damages and improved its functions.

The effect of angiotensin 1-7 and losartan on renal ischemic/reperfusion injury in male rats

Ischemia/reperfusion (I/R) is a major cause of acute kidney injury. Several studies have shown that renin angiotensin (Ang) system and activation of Ang II type 1 receptor (AT1) are involved in various forms of kidney diseases. Likewise, Ang 1-7 as a physiologic antagonist of AT1 and losartan could possibly protect the kidney against I/R damage. Therefore, we investigated renal injury by administering the drugs before and after I/R. Fifty-four male Wistar rats were randomly assigned to five groups as follows. 1, Sham operated; 2, saline group (as a control group); 3, losartan group; 4, Ang 1-7group; and 5, Ang 1-7 + losartan simultaneously. It should be noted that groups 2-5 consisted of two separate I/R-induced subgroups both receiving medication where the first groups received the treatment 15 min before induction of I/R while the medications were given to the second groups immediately after induction of I/R. Twenty four h after I/R, blood samples were collected, and then levels of serum urea nitrogen (BUN), creatinine (Cr), nitrite, malondialdehyde (MDA), lactate dehydrogenase (LDH) and total antioxidant capacity (TAC) were measured. Likewise, nitrite, MDA and TAC were measured in the homogenized kidney tissues. After the induction of I/R, the BUN, Cr, LDH, and kidney tissue damage score increased. Administration of Ang 1-7 alone or simultaneously with losartan decreased the levels of aforementioned factors. Also, kidney MDA and nitrate levels significantly increased after I/R induction (P < 0.05). According to the results of this study, it can be claimed that the effect of losartan in the presence of Mas receptor is statistically significant and kidney damage dramatically decreases.

Effects of Eugenol on Pain Response to the Formalin Test and Plasma Antioxidant Activity in High Fructose Drinking Water in Male Rats

Background:

Increased consumption of fructose in recent years has increased the risk of developing metabolic syndrome. In this syndrome, induction of oxidative stress, cellular dysfunction, and decrease of antioxidant capacity can change response to pain. Therefore, this study aims to investigate the antinociceptive and antioxidant effects of eugenol on metabolic syndrome induced by a fructose-rich diet in rats.

Methods:

The rats were randomly assigned to five groups, to be under experiment for eight weeks. The first, control group, the second fructose 10% plus tween 0.5% (Fr + veh), the third fructose 10% (Fr), and the fourth fructose 10% plus a single dose of eugenol 100 mg/kg (Fr + EoS). However, the fifth obtained fructose 10% plus a continuous dose of eugenol 20 mg/kg/day (Fr + EoC) for the last 10 days of the experiment. After formalin test, blood samples were taken from the animals’ hearts followed by analysis for biochemical factors.

Results:

This study shows that fructose administration does not change any pain response and there are not any changes in pain response between Fr group and control group. However, treatment with single and continuous dose of eugenol in Fr + EoS and Fr + EoC groups significantly decreases response to pain in the first and second phase of formalin test in comparison with Fr group (P<0.05). Continuous does of eugenol improved serum malondialdehyde and total antioxidant capacity levels in Fr + Eoc group in comparison with Fr group.

Conclusions:

In the present work, new findings suggest the beneficial effects of eugenol in pain relief, improved serum glucose, insulin levels, and improved antioxidant activity in metabolic syndrome.

Sex Difference in Gentamicin-induced Nephrotoxicity: Influence of L-arginine in Rat Model

Background:

L-arginine is an important precursor for the formation of nitric oxide (NO). According to previous studies, NO function is related to gender. Likewise, chronic renal diseases have lower prevalence in female. Gentamicin (GM) is an aminoglycoside antibiotic. According to some studies, males are more sensitive to GM renal nephrotoxicity. This study attempts to find protective effects of L-arginine on GM nephrotoxicity in male and female rats.

Methods:

Male and female rats were divided into eight groups: Rats were randomly assigned to 8 groups each including both male and female rats. The first and second groups received vehicle (saline), the third and fourth groups received gentamicin (80 mg/kg), the fifth and sixth groups received L-arginine (150 mg/kg), and finally, seventh and eighth groups received gentamicin+ L- arginine. Next, 9 days after administering drugs, blood samples were collected from the heart. After making sacrifices, the level of blood urea, creatinine (Cr), nitrite, and malondialdehyde (MDA) was measured in serums. Likewise, nitrite and MDA were measured in the homogenized kidney tissue.

Results:

GM significantly increased serum level of urea and Cr in male and female rats (P < 0.05). However, co-administration of GM + L-arginine significantly did not decrease urea and Cr level in male rats, whereas, in female rats, they significantly reduced (P < 0.05). In response to GM, renal MDA level increased in male and female rats (P < 0.05), and in the presence of GM + L-arginine, the level of MDA significantly decreased in both genders (P < 0.05).

Conclusions:

L-arginine demonstrated some protective effects in female rats but did not protect against GM nephrotoxicity in male rats for unknown reasons, probably related to the effects of sex hormones which needs further studies to be confirmed.

Losartan and magnesium sulfate administration reduce gentamicin-induced nephrotoxicity in rat model

Background: Nephrotoxicity is the most known side effect of gentamicin. In addition, renin angiotensin system (RAS) plays an important role in the pathogenesis of renal injury and nephrotoxicity. Hypomagnesaemia is other complication of gentamicin. Previous studies reported that magnesium plays an important role in cell enzymatic functions, reducing lipid peroxidation. Objectives: We investigated the role of losartan and magnesium sulfate (MgSO4 ) on gentamicin nephrotoxicity. Materials and Methods: In this study, rats randomly assigned to five groups. The first group, received saline, the second group received gentamicin 80 mg/kg/d, intraperitoneally (ip), and the third group, received a regular dose of losartan, 10 mg/kg/d + gentamicin 80 mg/kg/d. The fourth group received MgSO4 , 80 mg/kg/d + gentamicin 80 mg/kg/d. The fifth group obtained a continuous dose of gentamicin 80 mg/kg/d + losartan 10 mg/kg/d + MgSO4 80 mg/kg/d simultaneously. Nine days after administration of drugs, blood samples were collected from the heart. The level of urea, creatinine (Cr), malondialdehyde (MDA) and nitrite were measured in the animal serum and homogenized kidney tissue. Results: Gentamicin increased serum urea and Cr levels. The administration of losartan and MgSO4 lonely and combination of them, significantly reduced the levels of serum urea and Cr. Losartan alone and combination of losartan and MgSO4 compared with gentamicin, significantly decreased kidney MDA level too. Decrease of kidney nitrite level by gentamicin was compensated by the administration of losartan, MgSO4 alone or their combination. Additionally, losartan and MgSO4 alone and their combination together significantly reduced renal damage. Conclusions: The results of this study indicated that administration of losartan and MgSO4 individually and their combination decreased kidney nephrotoxicity and improved renal function. This effect is probably related to the improvement of antioxidant status and renal blood flow.

Cisplatin-Induced Nephrotoxicity; Protective Supplements and Gender Differences

Cisplatin (CDDP) has been widely used as a chemotherapeutic agent for solid tumors. The most common side effect of CDDP is nephrotoxicity, and many efforts have been made in the laboratory and the clinic to employ candidate adjuvants to CDDP to minimize this adverse influence. Many synthetic and herbal antioxidants as well as trace elements have been investigated for this purpose in recent years and a variety of positive and negative results have been yielded. However, no definitive supplement has so far been proposed to prevent CDDP-induced nephrotoxicity; however, this condition is gender related and the sex hormone estrogen may protect the kidney against CDDP damage. In this review, the results of research related to the effect of different synthetic and herbal antioxidants supplements are presented and discussed with suggestions included for future work.

Role of Angiotensin Type 2 Receptor on Nitric Oxide Production Response to Angiotensin II Administration in Ovariectomised Rats Treated with Estradiol

BACKGROUND

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).

METHODS

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 μg/kg/h) and the level of NO metabolite (nitrite) was measured before and after AngII infusion.

RESULTS

At the presence of AT2R, the serum level of nitrite in response to AngII administration in OVE groups increased significantly (P < 0.05).

CONCLUSIONS

However, this increase was abolished by AT2R antagonist. It seems that AT2R involves nitrite production response to AngII in OVE.

Sex differences in protective effect of recombinant human erythropoietin against cisplatin-induced nephrotoxicity in rats

INTRODUCTION

The protective role of recombinant human erythropoietin (RHE) against cisplatin-induced nephrotoxicity has been reported, but the role of sex differences is not clearly known. The aim of this study was to determine the sex-based difference in the protective effect of RHE against cisplatin-induced nephrotoxicity.

MATERIALS AND METHODS

Thirty-three Wistar rats were divided into 6 groups. According to protocol l, male and female rats were treated with RHE (100 IU/kg/d) for 3 days and then received a single dose of cisplatin (7 mg/kg). According to protocol 2, the rats received the same single dose of cisplatin and then were treated with RHE for 7 days. Two other groups of male and female rats received a similar regimen of protocol 2 except for saline instead of RHE. All the animals were sacrificed 1 week after cisplatin administration.

RESULTS

All of the experimental animals experienced weight loss. The percentage change of weight in male rats with protocol 1 was significantly less than that in male rats in protocol 2 and control groups. However, in female groups, the percentage of change in weights was slightly higher with protocol 2 than with protocol 1 and control treatment. Administration of RHE significantly decreased changes in serum creatinine, BUN, and malondialdehyde levels in male rats, but not in females. No significant difference was observed in serum nitrite level, kidney weight, and kidney damage score between the groups.

CONCLUSIONS

This study suggested that erythropoietin may lead to different responses against cisplatin-induced nephrotoxicity in male and female rats.

The effects of unripe grape extract on systemic blood pressure, nitric oxide production, and response to angiotensin II administration

Background:

Hypertension is the most common disease in the world. In Iranian folk medicine, unripe grape juice has been used as antihypertention remedy, but no data is documented for this popular belief. This study was designed to determine the effect of unripe grape extract (UGE) on blood pressure and the response to angiotensin II in rat.

Materials and Methods:

Unripe grape was collected, air dried, and extracted and concentrated. Four groups of Wistar rats received single doses of 125, 250, and 500 mg/kg of UGE or saline, respectively. The direct blood pressure and the serum nitrite level were measured one hour post UGE administration. The animals also were subjected to the infusion of various angiotensin II concentrations (100, 300, and 1000 μg/kg/min), and blood pressure was determined.

Results:

Mean arterial, systolic, and diastolic pressures (MAP, SP, and DP) in all UGE treated groups were less than the control group, but only at the dose of 125 mg/kg (Group 1) they were significantly different (P < 0.05). The level of nitrite in groups 1-3 were significantly greater than the control group (P < 0.05). No significant differences were detected for the MAP, SP, and DP to different concentrations of angiotensin II among these groups.

Conclusion:

UGE potentially attenuate MAP, SP, and DP via vasodilatation induced by nitric oxide production.

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: Gender-Related Difference

BACKGROUND

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.

METHODS

Anesthetized and catheterized male and female Wistar rats were subjected to one-hour continuous infusion of Ang II (~20 μg/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.

RESULTS

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.

CONCLUSIONS

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.

Protective Role of Silymarin and Deferoxamine Against Iron Dextran-induced Renal Iron Deposition in Male Rats

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSION

It seems that SM is a nephroprotectant agent against KID in acute iron overload animal models.

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

BACKGROUND

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.

MATERIALS AND METHODS

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.

RESULTS

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).

CONCLUSION

According to our findings, endometriosis is not associated with change in the level of circulating VEGF.

Evidence against protective role of sex hormone estrogen in Cisplatin-induced nephrotoxicity in ovarectomized rat model

BACKGROUND

Cisplatin (CP) is an effective drug in cancer therapy to treat the solid tumors, but it is accompanied with nephrotoxicity. The protective effect of estrogen in cardiovascular diseases is well-documented; but its nephron-protective effect against CP-induced nephrotoxicity is not completely understood.

MATERIALS AND METHODS

Thirty ovarectomized Wistar rats were divided in to five groups. Groups 1-3 received different doses of estradiol valerate (0.5, 2.5 and 10 mg/kg/week) in sesame oil for 4 weeks, and at the end of week 3, a single dose of CP (7 mg/kg, intraperitoneal [IP]) was administrated. Group 4 (positive control) received the same regimen as group 1-3 without estradiol without vehicle. The negative control group (Group 5) received sesame oil during the study. The animals were sacrificed 1 week after CP injection for histopathological studies.

RESULTS

The serum level of blood urea nitrogen and creatinine, kidney tissue damage score (KTDS), kidney weight and percentage of body weight change in CP-treated groups significantly increased (P < 0.05), however, there were no significant differences detected between the estrogen-treated groups (Groups 1-3) and the positive control group (Group 4). Although, estradiol administration enhanced the serum level of nitrite, it was not affected by CP. Finally, significant correlation between KTDS and kidney weight was detected (r (2) = 0.63, P < 0.01).

CONCLUSION

Estrogen is not nephron-protective against CP-induced nephrotoxicity. Moreover, it seems that the mechanism may be related to estrogen-induced oxidative stress in the kidney, which may promote the nephrotoxicity.

Estrogen Abolishes Protective Effect of Erythropoietin against Cisplatin-Induced Nephrotoxicity in Ovariectomized Rats

Introduction. Nephrotoxicity is one the side effect of cisplatin therapy and erythropoietin has been candidate as a nephroprotectant agent. However, its nephroprotective effect when it is accompained with estrogen has not been studied in female. Methods. 27 ovariectomized female Wistar rats divided into five groups. Groups 1 & 2 received estradiol valerate (0.5 mg/kg/week) for four weeks, and single dose of cisplatin (7 mg/kg, ip) was administrated at the end of week 3. Then the group 1 was treated with erythropoietin (100 U/kg/day), and the group 2 received vehicle during week 4. Groups 3 and 4 were treated similar to group 1 and 2, except for placebo instead estradiol valerate. Group5 (negative control) received placebo during the study. Animals were killed at the end of week 4. Results. In non-erythropoietin treated rats, cisplatin significantly increased the serum levels of blood urea nitrogen and creatinine (P < 0.05). However, these biomarkers significantly decreased by erythropoietin (P < 0.05). The weight loss, kidney weight, and kidney tissue damage score in rats treated with cisplatin but without estradiol were significantly less than the values in similar group when estradiol was present (P < 0.05). Conclusion. It seems that erythropoietin could protect the kidney against cisplatin-induced nephrotoxicity. This protective effect was not observed when estrogen was present.

Sex differences in the renal vascular response to angiotensin II involves the Mas receptor

AIM

The renin-angiotensin system (RAS) depressor arm, particularly renal angiotensin type 2 receptor (AT(2) R) and Mas receptor (masR) expression, is enhanced in females, which may contribute to renal and cardiovascular protection. We examined the hypotheses that masR activation increases renal blood flow (RBF) at rest and attenuates the reduction in RBF in response to angiotensin II (AngII) infusion in female rats. Furthermore, we postulated that combined activation of the AT(2) R and masR would produce a greater response than masR activation alone.

METHODS

In anaesthetized male and female Wistar rats, mean arterial pressure (MAP) and RBF responses during graded AngII infusion (30-1000 ng kg(-1)  min(-1) i.v.) were assessed following pre-treatment with vehicle, the masR antagonist A779, or A779 plus the AT(2) R antagonist PD123319.

RESULTS

Basal MAP was not altered by any pre-treatment. Basal RBF decreased approx. 20% in female (P < 0.05), but not male rats in response to A779. However, basal RBF was not altered by A779 + PD123319. AngII infusion reduced RBF in a dose-related fashion (P(dose)  < 0.0001) and masR blockade did not alter the RBF response to AngII infusion in male or female rats. However, A779 + PD123319 attenuated the reduction in RBF response to AngII in females (P(group)  < 0.005), but not males.

CONCLUSION

The impact of the masR on renal haemodynamics appears to be sexually dimorphic, with greater effects in female than male rats. However, the paradoxical effects of dual AT(2) R and masR blockade suggest that a greater understanding of the complex interactions between RAS components is required before the therapeutic opportunities of AT(2) R and/or masR stimulation can be advanced.

The Role of Magnesium Supplementation in Cisplatin-induced Nephrotoxicity in a Rat Model: No Nephroprotectant Effect

OBJECTIVES

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

A combination of vitamin C and losartan for cisplatin-induced nephrotoxicity in rats

INTRODUCTION

The nephroprotective effect of co-administration of vitamin C and losartan as prophylaxis against cisplatin-induced nephrotoxicity (CIN) was evaluated.

MATERIALS AND METHODS

Co-administration of vitamin C and losartan was compared with losartan (10 mg/kg), vitamin C (250 mg/kg), and placebo in 4 groups of rats with CIN. The prophylactic agents were injected daily for a period of 4 days, and on day 3, a single dose (6 mg/kg) of cisplatin was administrated. The animals were sacrificed 7 days later for pathological examination of the kidneys.

RESULTS

Cisplatin prevented the animals' weight gain. The serum levels of creatinine and blood urea nitrogen increased within the groups with CIN, but no significant difference was observed between the groups. The prophylaxis has no effect on serum osmolality, total protein, or nitrite concentrations. The kidney tissue damage was scored, and losartan provided a lower damage score than vitamin C and a combination of vitamin C and losartan.

CONCLUSIONS

We concluded that co-administration of vitamin C and losartan was not more effective than the administration of vitamin C or losartan alone.

The protective role of endogenous nitric oxide donor (L-arginine) in cisplatin-induced nephrotoxicity: Gender related differences in rat model

BACKGROUND

Cisplatin (CP) as a potential drug for solid tumors produces nephrotoxicity and disturbs endothelial function. CP induced nephrotoxicity may be gender related. Nitric oxide plays a pivotal role in endothelial function and L-arginine as endogenous NO donor promotes endothelial function. The role of L-arginine in CP induced nephrotoxicity model and its gender related was investigated in this study.

METHODS

Thirty three Wistar rats were randomly assigned to four groups. The groups 1 (male, n = 6) and 2 (female, n = 11) received a single dose of L-arginine (300 mg/kg, ip), and the day after, they received a single dose of CP (7 mg/kg). The group 3 (male, n = 9) and 4 (female, n = 7) were assigned to the same regimen except for saline instead of L-arginine. All animals were sacrificed one week after CP administration. The levels of blood urea nitrogen (BUN), creatinine and nitrite were measured. The kidneys were also removed for pathological investigations.

RESULTS

Five animals died. All CP treated animals lost weight. The normalized weigh loss was significantly different between male and female in CP+L-arginine treated animals (p < 0.05). BUN and creatinine were increased significantly in male treated with CP and in female treated with CP+L-arginine (p < 0.05). L-arginine reduced BUN in male (not in female) when compared with control groups (p < 0.05). The level of nitrite was increased significantly in L-arginine treated animals. Kidney tissue damage score and normalized kidney weight were greater in females treated with CP+ L-arginine than female received CP alone (p < 0.05).

CONCLUSIONS

L-arginine may protect against CP induced nephrotoxicity in male, but it promotes the induced damage in female. The exact mechanism need to be defined.