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

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

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

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

Testicular testosterone/oestradiol ratio in experimental hyperprolactinemia

To determine the effect of experimentally induced hyperprolactinemia in adult male rats on the testicular testosterone / oestradial ratio. Ten rats -were administered a D[2]-dopamine receptor antagonist [metoclopramide] I.P [2.2 mg/kg] over 14 days to induce hyperprolactinemia. Ten control rats were given NaCl I.P for the same duration. Prolactin hormone was assayed in the serum. Testosterone and oestradial hormones were assayed in both serum and testicular homogenates. Testicular testosterone / oestradiol ratio was estimated. Serum testosterone, serum oestradiol, testicular testosterone and testicular testosterone/oestradiol ratio were significantly decreased in the hyperprolactinemic group. A significant positive correlation was detected between serum and testicular testosterone in both studied groups. The disturbed testicular testosterone/oestradiol ratio may be a possible mechanism underlying antifertility effect of hyperprolactinemia

Plasma homocysteine as an indicator of folate and vitamin B[12] status in children with acute lymphoblastic leukemia

Folate and vitamin B[12] are important in ensuring proper DNA replication and normal cell division. Their depletion might enhance carcinogenesis. The sulphur containing amino acid homocysteine gained considerable interest as a useful marker of impaired function of folate and vitamin B[12]. The present work aimed to evaluate plasma homocysteine level as a more sensitive indicator of folate and vitamin B[12] status in children with acute lymphoblastic leukemia. This study included fifteen children with newly diagnosed acute lymphoblastic leukemia attending pediatric department of Shatby Hospital, Alexandria University. The control group included fifteen normal healthy volunteers matched for age and sex. In patients, blood samples were collected at the time of diagnosis before any treatment. RBC's folate, plasma folate and vitamin B[12] were estimated using RIA kit. Plasma homocysteine was determined using EIA kit. RBC's folate, plasma folate and vitamin B[12] were significantly lower while plasma homocysteine was significantly elevated in the patient group when compared to the control group. Plasma homocysteine correlated negatively with RBC's folate in both studied groups. This study showed a strong association between folate deficiency, hyperhomocysteinemia and ALL in children. Prospective studies are necessary to further define whether alterations in plasma tHcy and RBC's folate levels can be considered as risk markers or are a consequence of progression of acute lymphoblastic leukemia

Subclinical hypothyroidism and dyslipidemia in pre- eclampsia

Aim: To investigate the thyroid function and lipid profile in pre-eclamptic patients and to assess the possible association between subclinical thyroid alterations and dyslipidemia in the pathophysiology of pre-eclampsia. Subjects and Thirty pre-eclamptic patients were selected from the Shatby Hospital [15 with severe pre-eclampsia [group I], and 15 with mild disease [group II]]. Twenty five healthy normotensive volunteer women were enrolled as controls [15 pregnant [group III] and 10 non-pregnant [group IV]]. The following parameters were estimated in serum: thyroid stimulating hormone [TSH], free thyroxine [FT4], and the lipid profile [TC, TG, HDL-C]. LDL-C, VLDL-C and TC/HDL-C ratio were calculated. In addition, serum thyroid peroxidase auto-antibodies [TPO-ABs] were detected. Mean serum TSH was significantly elevated, while FT4 was significantly decreased in group I and II. The frequency of TPO-ABs positivity was [16.7%] in pre-eclamptic cases. TC was significantly elevated in both group I and II. TG was also elevated in them reaching significant levels in group II, while HDL-C was significantly decreased in group I. TSH was significantly negatively correlated with FT4 and positively with both TC and TG in pre-eclamptic cases. Conclusions: The disruption of thyroid hormone homeostasis during pregnancy due to subclinical alterations in thyroid function and the associated hyperlipidemia may play a role in the pathophysiology of pre-eclampsia