Effect of hyperhomocysteinemia on erythrocyte function and its impact on erythropoiesis in experimental rats

The current work was conducted to study the possible effect of hyperhomocysteinemia [HHcy] on some erythrocytic functions as a cause of anemia and its impact on erythropoietin [EPO] release in experimental rats. Forty adult male albino rats were divided into two main groups, the control group [Group I] and the hyperhomocysteinemic group [HHcy] [Group II]. Hyperhomocysteinemia was induced by subcutaneous injection of DL- homocysteine at a dose of 100 mg/kg/day for 4 weeks. At the end of the fourth week each main group was subdivided into two subgroups, [Ia] control, [Ib] Hypoxic-control [IIa] and HHcy, [IIb] Hypoxic-HHcy. Hypoxia was induced by a single intra-peritoneal injection of desferrioxamine [200 mg/kg] 22 hours before decapitation. Whole blood was used for determination of erythrocytic fragility, hematological parameters, reticulocyte percentage. Homocysteine, erythropoietin [EPO], urea and creatinine were estimated in plasma. Erythrocytes were used for estimation of lipid peroxidation, G6PDH activity and membrane separation for deten-nination of Na[+] K[+] ATPase enzymatic activity. Homocysteine, EPO and creatinine plasma levels, and reticulocyte% and erythrocytic lysis in addition to erythrocyte lipid peroxidation were all significantly higher, while G6PDH and Na[+] K[+]- ATPase enzymatic activities were significantly lower in the HHcy group as compared to the control group. A significant positive correlation was found between total Hcy plasma levels and erythrocyte lipid peroxidation. EPO plasma levels showed a significant increase in response to hypoxic stimulation in the control group, while blunted response was observed in the HHcy group. It could be concluded that disturbance in erythrocyte membrane and enzymatic functions in HHcy increases the susceptibility of RBCs to hemolysis and reduces its life span. Hyperhomocysteinemia also impacts EPO release to hypoxic stimulation which may be due to damaging effect of HHcy on renal cells

protective effect of antioxidants on renal ischemia-reperfusion injury in the rat

Renal ischemia-reperfusion [I/R] is of clinical interest because of its role in renal failure and also in renal graft rejection. There is increasing evidence to suggest that reactive oxygen species [ROS] play a role in the pathogenesis of I/R injury in the kidney. This study was designed to investigate the protective effect of some dietary antioxidants [garlic, vitamin E or vitamin A + Se [+2]] against the damage inflicted by [ROS] during renal I/R. Five groups of male albino rats were used in this study each composed of 10 rats. Group I: Sham-operated control group. Group II: I/R group [not treated] unilaterally nephrectomized after subjection of the left renal pedicle to 60 minutes of nontraumatic occlusion followed by 24 hours of reperfusion. Group III: the same procedure as group II but animals were preconditioned by adding garlic powder to their diet 80 mg kg[-1] daily for one month. Group IV: like group III but vitamin E [6.5 mg kg[-1]/d for one month] was supplemented to diet. Group V: like the two previous groups III and IV but vitamin A [7.9 mg/kg[-1]] and Se[+2] [50 microg/kg[-1]] were added daily to the rats' diet for one month. At the end of the reperfusion period, the rats were sacrificed. Malondialdehyde [MDA], Reduced glutathione [GSH] concentrations, superoxide dismutase [SOD], glutathione reductase and glutathione peroxidase enzymatic activities were determined in plasma and kidney homogenates of all groups. Serum creatinine and blood urea concentrations, were measured, for the evaluation of renal function. Also Na[+]-K[+]-ATPase was determined in kidney homogenates. Ischemic reperfused [l/R] animals demonstrated severe detonation of renal function and a significant renal oxidative stress. Pretreatment of animals with garlic, vitamin E or vitamin A + Se [2+] markedly attenuated renal dysfunction and oxidative stress as manifested by reducing blood urea, serum creatinine, MDA and restored depleted renal antioxidant enzymes. Na[+]-K[+]-ATPase activity, which was decreased in the I/R group, increased in the animals preconditioned with vitamins E and A + Se[2+]. From this it can be concluded that ROS play a causal role in I/R induced renal injury and supplementing the animals with garlic and/or other dietary antioxidants exerts protective effects. Therefore, it is recommended to supply patients expected to suffer from I/R renal injury with these antioxidants

Functional significance of lipid changes under the effect of inhalational anesthetics

Small concentrations of inhaled anesthetics can induce type II pneumocytes dysfunction and affect surfactant production and exacerbate oxidant mediated lung injury. The aim of the present work was to study the interrelationship between alveolar surfactant lipid composition and that of the lung tissue aiming to understand the sequence of events in the pathogenesis and pathophysiology of acute lung injury [ALI] after inhalation anesthesia. 60 albino rats were used in this study. Lipids were extracted from the lung tissue and alveolar surfactant obtained by bronchoalveolar lavage from rats which were subjected to 1-2% halothane or nitrous oxide anesthetics. The following parameters were determined on the extracted lipids: total lipids [TL], triglycerides [TG], total cholesterol [T-ch], total free fatty acids [FFA], total phospholipids [TPL], phospholipids fractions, lecithin [phosphatidyl cholin Pc], lysolecithin, cephalin [phosphatidyl ethanol amine PI] and sphingomyelin. I- Effect of halothane In the surfactant: Halothane decreased all parameters studied with the exception of FFA and sphingomyelin which was increased compared to controls. Cephalin did not change. However, in the lung FFA, lecithin and lysolecithin increased while all other parameters decreased. II- Effect of nitrous oxide [N[2]O]: In the surfactant: All parameters also decreased except lysolecithin, cephalin and sphingomyelin, which were increased. However, FFA did not change significantly from controls. In the lung: Lecithin, lysolecithin and FFA increased whereas the other parameters decreased. Halothane and N[2]O differ as regards their effect on the lipid profile of the surfactant or lung tissue. The functional significance of the alteration was discussed

Effect of swimming exercise on lipid peroxidation, leptin-insulin axis and brain Na+-K+-ATPase enzymatic activity in rats

Several authors suggest that the leptin-insulin axis functions as the afferent limb of a negative feed-back loop that provides sensory input to the hypothalamus about energy balance and body weight. Aim: The objective of this work was to study the effect of acute swimming exercise versus chronic swimming exercise program on blood glucose, adiposity and insulin resistance indices, and lipid peroxides levels as an important effect of exercise is the production of lipid peroxides which can modulate insulin and leptin action. Also, brain sodium-potassium-adenosine triphosphatase [Na[+]-K[+]-ATPase] was determined as it is an important modulator of leptin and insulin action in the hypothalamus. 36 adult rats were used in this study divided into 3 groups, each of 12 rats. Group I is the control sedentary group, group II acute swimming rats and group III chronic swimming rats. Mean serum glucose, insulin and leptin levels, insulin resistance and adiposity indices were significantly decreased while serum lipid peroxides was significantly elevated in group Ill compared to both groups I and II. Brain Na[+]-K[+]-ATPase enzymatic activity was significantly decreased in both groups II and III. Insulin was positively correlated with insulin resistance index in both groups [I and II] and leptin in group III. chronic swimming exercise training exerted beneficial effects by reducing body fat index, blood glucose and leptin, improving insulin sensitivity, brain Na[+]-K[+]-ATPase enzymatic activity and hence cognitive function. On the other hand, short strenuous exercise increased serum lipid peroxides [MDA], Serum glucose, thereby inducing oxidative stress

Expression of interleukin[il]-18and il-6 in gastric cancer :diagnostic and prognostic role

Gastric cancer is the second most common cancer worldwide. The purpose of this study was to compare the recently identified interleukin [IL]-18, as well as IL-6 values in patients with gastric ulcer and gastric cancer to assess their diagnostic and prognostic values in patients with gastric cancer. The study comprised 40 patients attended for diagnostic upper gastrointestinal [GIT] endoscopy; 14 with histopathologically proven gastric cancer [Group I], 16 patients with gastric ulcer [Group II] and 10 patients with normal upper GIT endoscopy who served as controls [Group III]. All involved individuals were subjected to clinical examination, liver and renal function tests, complete blood picture, ESR, C-reactive protein, plain chest X-ray, abdominal ultrasound, urease test and gram staining of mucosal biopsies for Helicobacter pylori detection. Additionally chest,abdominal CT and bone scanning for group I gastric cancer were done to detect any metastasis. IL-18 and IL-6 gastric muscosal mRNA expression was assessed by quantitative real time-PCR [QRT-PCR] and their serum levels were estimated by ELISA. Gastric mucosal mRNA expression in parallel to serum values of IL-18 and IL-6 showed significant highly in-creased values in gastric cancer group compared to gastric ulcer and control groups [P<0.001] with elevated values in gastric ulcer group than those in controls. In gastric ulcer group, a positive relation was found between the studied cytokines and the histologically graded precancerous gastric lesions; gastric glandular atrophy grade was correlated with ser-um IL-18 [r=0.77; P < 0.001], gastric mRNA expression of IL-18 [ r= 0.603;P < 0.01] and IL-6 [r = 0.457;P <0.05], also intestinal metaplasia was positively related to IL-18 serum [t=-2.977; P < 0.01] and gastric mRNA expression [t =-2.365; P < 0.05] values. Higher cytokine values were related to H pylori infection in gastric ulcer [P < 0.01] not in gastric cancer group. In gastric cancer group a significant positive correlation was found between the cellular differentiation grade and IL-18 serum [r = 0.712; P <0.01] and gastric mRNA expression [ r = 0.658;P < 0.01] values, while IL-6 serum [r = 0.817; P <0.01] and gastric mRNA expression [r=0.844; P <0.01] values were positively correlated with the gastric cancer stage. Also patients with distant metastasis showed significantly higher IL-6 serum[t=-6.218 ; p < 0.001] and gastric mRNA expression [t = -2.47; P < 0.01]values compared to those without metastasis

In conclusion: IL-18 as a recently identified cytokine as well as IL-6 suggested to be vitally involved in gastric cancer pathogenesis. Serum IL-18 and IL-6 may be useful diagnostic markers for patients with gastriccancer. IL-18 may be used as a predictive marker of tumor grade and serum IL-6 could be used as a tumor marker for advanced gastric cancerstage and metastasis

Effect of hemodialysis on hexose monophosphate pathway of red blood cells in end stage renal disease patients

To evaluate the role of hemodialysis [HD] on the correction of hexose monophosphate pathway [HMP] in chronic hemodialyzed patients. Ten end stage renal disease [ESRD] patients on chronic hemodialysis were selected from the nephrology unit of Medical Research Institute. All patients were on maintenance HD. [Three times per week for more than one year]. Hemoglobin [Hb] concentration, lipid peroxides as malonyldialdehyde [MDA], glutathione reductase [GR], glutathione peroxidase [GPX], glucose 6-phosphate dehydrogenase [G6PD], oxidized glutathione [GSSG] and reduced glutathione content [GSH] were estimated in erythrocytes. In addition, plasma creatinine was determined. All these parameters were estimated before and after haemodialysis session. Mean plasma creatinine was significantly decreased after haemodialysis. Mean erythrocyte lipid peroxides and GR were significantly increased after haemodialysis while GPX enzymatic activity was significantly decreased after haemodialysis. The above changes may indicate that HD enhances the oxidative-antioxidant defense system, but with no improvement of the anemia or correction of HMP pathway. The use of vitamin E coated membranes in the haemodialyzers and administration of antioxidants to hemodialyzed patients is recommended

Significance of toll-like receptors 2 and 4 mRNA expression in chronic hepatitis C virus infection

Hepatitis C virus [HCV] induces inflammatory signals leading to progressive liver damage. The mechanism of HCV involvement in the host's innate immune responses has not been well characterized and little is known about the molecular mechanisms by which immune cells recognize HCV. In this work we studied Toll-like receptor [TLR] 2 and TLR4, in chronic HCV infection, as recently identified important components of the innate immunity in humans as microbial recognition receptors. The study involved 30 HCV patients; 15 with chronic hepatitis [group I] and 15 with liver cirrhosis [group II], in addition to 10 healthy controls [group III]. mRNA expression of TLR2 and TLR4 in peripheral blood mononuclear cells [PBMCs] was examined using reverse transcriptase PCR. This in relation to quantitative analysis of HCV-RNA by Real time-PCR and serum tumor necrosis factor-alpha [TNF-alpha] estimation by ELISA. Significant correlation was found, in HCV patients, between the viral load and TLR2 [r=0.704; p<0.01 in group I and r =0.629; p <0.05 in group II] and TLR4 [r=0.549; p <0.05 in group I and r =0.596: p <0.05 in group II] and between TLR2 and TLR4 [r=0.814: p< 0.001 in group I and r =699 p< 0.01 in group II]. Overexpress ion of TLR2 and TLR4 was detected in chronic hepatitis patients as compared to controls [p< 0.001]. In cirrhotic patients down regulation of TLR4 mRNA expression was found as compared to group I chronic hepatitis [p< 0.00 1], while TLR2 showed a steady overexpression. A positive correlation was also detected between TLR2 expression and TNF-alpha in HCV patients [r=0.571; p <0.05 in group I and r = 0.723: p< 0.01 in group II], while a weak relationship was found between TLR4 and TNF-alpha in cirrhotic patients. [r =0.359; P> 0.05]. TLR2 correlated significantly with the hepatic necroinflammatory activity grade [r = 0.629; P <0.05 in group I and r 0.502; p < 0.05 in group II], while TLR4 correlated with the fibrosis stage [r =0.682; P < 0.01]. On the other hand no correlation could be detected between TLR2 and TLR4 and the child's grade in cirrhotic patients. It is concluded that TLR2 and TLR4 may play a vital role in HCV recognition and suggested to be involved in the initiation and progression of HCV induced liver diseases. Advanced molecular reseaches modulating TLRs in HCV infection were recommended, that may be of hopeful protective as well as therapeutic values

Pathophysiological effects of mobile phone radiations on the brain: an experimental study

The increased use of mobile phone worldwide has focused interest on the possible effects of radiofrequency fields on health. However, until now no satisfactory mechanism has been proposed to explain the biological effects of these radiations. Thus this study was undertaken in order to investigate the effect of radiations emitted from mobile phone on: Malonyldialdehyde [MDA], as a lipid peroxidation product, and serotonin concentrations, as well as the activities of acetylcholinesterase [AChE] and sodium-potassium ATP-ase [Na[+] K[+] ATP-ase] enzymes in the different parts of rats brain. The study was conducted on twenty adult male albino rats. Ten were exposed to radiations emitted from cellular phone [the experimental group] and ten rats were in the same exposure conditions but the mobile phone was turned off [the control group]. Na[+] K[+] ATP-ase enzymatic activity was significantly lower while MDA and serotonin concentrations were significantly higher in all studied brain parts of the experimental group. AChE was found to be significantly lower only in the cerebellum of the experimental group. These results support the interaction of radiofrequency fields of mobile phones with biological systems. Oxidative stress and diminished Na[+] K[+] P-ase enzymatic activity in addition to disturbance in serotonergic neurons and possibly cholinergic neurons, all may play a role in the mechanism of adverse effects of electromagnetic radiations. Further studies are needed so as to find the threshold level for exposure to electromagnetic field [EMF] that is not adverse to human health

Dysfunctional nitric oxide and 8-epi-prostaglandin F2alpha synthesis in healthy smokers

Background: Cigarette smoking, a major cardiovascular risk factor, has been shown to be associated with impaired endothelium- dependent vasodilatation [EDV]. Nitric Oxide [NO] being a primary vasodilator produced by endothelial cells, its production is probably affected by cigarette smoking. Cigarette smoke contains superoxide anions and a great number of other reactive oxygen species [ROS], the accumulation of which brings about oxidative damage of endothelial cells. A free radical catalyzed isomers of arachidonic acid [8-epi- PGF2infinity] is a potent vasoconstrictor and serves as a marker of oxidative stress

Objective: To evaluate the level of serum [NO] and urinary 8-epi- PGF2infinity in mild, moderate, and heavy smokers and to correlate their levels with urinary cotinine which is considered a sensitive markers of exposure to nicotine of tobacco smoke

Subjects: 20 heavy smokers, 20 moderate smokers, 20 mild smokers, and 20 controls were the material of the present study

Results: The present study revealed significant increase in urinary 8-epi- PGF2infinity in smokers compared to control subjects. Also significant increase was found in urinary 8-epi- PGF2infinity in heavy compared with moderate smokers. However, there was a significant decrease in serum [NO] in the same two groups as compared to controls. Positive correlation for urinary 8-epi- PGF2infinity and negative correlation for serum [NO] as compared to urinary cotinine were detected. It may be concluded that concentration of 8-epi- PGF2infinity and cotinine in the urine as well as NO in the sera of smokers might give more accurate information about ROS which play an important role in the pathogenesis of many diseases affecting the physiological functions of body systems

Association between serum OPG/s rankl system and leptin with aging in male rats

Increasing evidences have suggested the association between serum leptin and bone formation. Osteoprotegerin [OPG], an osteoblast derived regulator of bone resorption and formation binds with soluble receptor activator of nuclear factor Kappa beta ligand [sRANKL] on osteoclast surface -which binds to its cognate receptor RANK on the osteoclast precursor. Thus, OPG/RANKL/RANK system controls the balance in bone formation and resorption. This study is designed to evaluate whether the OPG/sRANKL system and leptin levels are modified with aging and how they are related to bone and aortic changes. Three groups of rats were selected according to age, 4 months old [Group I], 12 months old [Group II] and 24 months old [Group III]. Serum levels of OPG, sRANKL, leptin, calcium and phosphorus [in sera and aortic extracts] were determined. Histopathological examination of rat femur and aorta from each group was also done. ANOVA test revealed significant difference between the three groups. The aged group [Group III] had higher calcium levels in sera and aortic extracts, serum phosphorus, serum sRANKL, leptin with increased sRANKL/OPG ratio. However OPG was significantly decreased in the same group in comparison to the other 2 groups. A significant negative correlation between serum OPG and sRANKL/OPG ratio [r = -0.879, p < 0.001] and body weight [r = -0.763, p < 0.01] and positive correlation between leptin and sRANKL/OPG ratio [r = 0.734, p < 0.01] and Ca aortic extract [r = 0.844, p < 0.01]. The disruption of OPG/sRANKL system and leptin with old age due to deficient OPG, high serum sRANKL and leptin resistance would represent a link between arterial calcification and bone resorption that are mostly present in the elderly

Effect of dietary garlic supplementation on lipid profile, oxidant-antioxidant status and aortic mechanical properties in experimental atherosclerosis

Experimental atherosclerosis was induced in a group of chicken [1 day old] by feeding a standard chicken diet supplemented with 1% cholesterol for twelve weeks. Another group was given the same diet supplemented with garlic [80 mg/kg body weight/day] for twelve weeks. The third group received standard poultry diet and served as controls. The alterations of lipids, lipid peroxidation products and antioxidant parameters of plasma and liver as well as the changes in the mechanical properties of the arterial walls were investigated. Hypercholesterolemia, a significant increase in low density lipoprotein cholesterol [LDL-C], triglycerides [TG] and phosphatidylcholine phospholipid fraction [PC] together with the significant decrease in high density lipoprotein cholesterol [HDL-C], very low density lipoprotein cholesterol [VLDL-C], total phospholipids and lysophosphatidylcholine [LPC] percent, induced by cholesterol feeding, were almost corrected by garlic administration. Lipid peroxidation products concentrations were significantly higher in atherosclerotic chicken and returned to almost control values by dietary garlic supplementation. In a corollary fashion, pronounced effect of garlic on antioxidants including liver glutathione [GSH], glutathione peroxidase [GPx], glucose-6-phosphate dehydrogenase [G6PDH], superoxide dismutase [SOD] and plasma antioxidant activity, expressed as D[max] was clearly noticed through restoration of their levels towards normal values after impairment under hypercholesterolaemia. As regards the mechanical properties, ultimate strain [U.S] of the thoracic aorta was significantly increased in the atherosclerotic group of chicken while the tensile strength [T.S] decreased significantly. The inner diameter of both thoracic and abdominal aortae decreased significantly in atherosclerotic group of chicken. These changes were returned to almost control values by addition of garlic powder to diet. These results suggest that garlic supplemented diet corrected not only pathological, lipids and antioxidant parameters but also the mechanical properties of the aortae