The effects of walnut supplementation on hippocampal NMDA receptor subunits NR2A and NR2B of rats.

OBJECTIVES: Walnuts contain numerous selected dietary factors that have an impact on brain functions, especially learning and memory formation in the hippocampus. Hippocampal N-methyl d-aspartate receptors (NMDARs) are involved in the formation of cognitive functions. In this study, we aimed to investigate the molecular effects of walnut supplementation on the hippocampal expressions of NMDARs involved in cognitive functions and lipid peroxidation levels in rats. METHODS: The male Sprague-Dawley rats (6 months old, n = 24) were fed with a walnut-supplemented diet (6% walnut diet, n = 12) and a control diet (rat food, n = 12) as ad libitum for 8 weeks. At the end of this period, NMDAR subunits NR2A and NR2B in the hippocampi were assayed by western blotting. Lipid peroxidation levels were measured using the thiobarbituric acid. RESULTS: The expression of NR2A and NR2B was elevated in the walnut-supplemented rats compared with the control group (P < 0.05). In addition, the levels of lipid peroxidation in the walnut-supplemented group were significantly decreased compared with the control group. DISCUSSION: We suggested that walnut supplementation may have protective effects against the decline of cognitive functions by regulating NMDAR and lipid peroxidation levels in the hippocampus. The study provides evidence that selected dietary factors (polyunsaturated fatty acids, melatonin, vitamin E, and flavonoids) within walnut may help to trigger hippocampal neuronal signal transduction for the formation of learning and memory.

Evaluation of Cardiac Markers in Children Undergoing Hematopoietic Stem Cell Transplantation.

BACKGROUND: Early life-threatening cardiotoxicity and cardiac death have been reported after hematopoietic stem cell transplantation (HSCT). The purpose of the current study was to evaluate cardiac toxicity of conventional chemotherapy followed by HSCT with cardiac markers: heart-type fatty acid binding protein (H-FABP), glycogen phosphorylase BB (GPBB), high sensitive C reactive protein (hsCRP) cardiac troponin I, (cTnI), creatine kinase MB (CK-MB mass) and myoglobin. METHODS: A total of 20 children who underwent HSCT for malignant and non-malignant diseases were included in this study. Blood samples were collected from all patients in 0th, 7th and 21st day for evaluating these cardiac biomarkers. The patients' echocardiography was assessment before and after one-month of HSCT. RESULTS: Serum 21st H-FABP level was significantly higher when compared with the 0th day H-FABP level (P < 0.05) . 7th day hsCRP level was significantly higher than 0th and 21st day levels (P < 0.05). Interestingly, 7th day GPBB level was significantly lower than 0th and 21st day levels (P < 0.05). Myoglobin, CK-MB mass and cTnI biomarkers remained within the reference range in all patients. CONCLUSIONS: This study showed that H-FABP and hsCRP both seem to be promising markers for evaluation of cardiotoxicity in HSCT process and probably superior to GPBB, cTnI, CK-MB mass and myoglobin.

The correlation of serum levels of leptin, leptin receptor and NO x (NO 2 (-) and NO 3 (-)) in patients with obstructive sleep apnea syndrome.

The aim of this study was to investigate the relations between nitric oxide (NO) and leptin levels in a cohort of untreated adult Obstructive sleep apnea syndrome (OSAS) patients. Between June 1, 2012, and January 1, 2013, we evaluated a total of 58 subjects including 36 OSAS patients and 22 healthy controls, both polysomnographically confirmed. Following the completion of polysomnographic evaluation, serum samples were taken at 08:00. Leptin, leptin receptor, NO2 (-) and NO3 (-) levels were analyzed by commercial ELISA kits. Data analysis was performed using the Statistical Package for the Social Sciences (SPSS) version 16.0 (SPSS Inc., Chicago, IL, USA). There was no statistically significant difference between the OSAS patients and control groups with relation to the demographic parameters and body mass index (p > 0.05). Significantly higher serum leptin and plasma NO levels were found in OSAS patients compared to the controls (p < 0.001). In this study, higher leptin levels which were positively correlated with NO levels in OSAS group may indicate a possible link with increased incidence of airway pathologies in these patients.

Effect of atorvastatin on atherosclerotic plaque formation and platelet activation in hypercholesterolemic rats.

We aimed to investigate whether atorvastatin influenced the CD40-CD40L pathway in atherosclerosis formation in rats fed a high cholesterol diet. Thirty-six male Wistar rats were divided among 4 groups as follows: control (C), statin (S), 5% cholesterol fed (HC), and statin-administered hypercholesterolemic (HCS). Serum levels of lipids, soluble CD40L, platelet factor 4, and interleukin-6 were assayed with commercial kits. The number of platelets expressing surface P-selectin, CD40, and CD40L were determined by flow cytometry. Aortas were examined for fatty streaks. In the HC group, we observed a significant increase in serum lipid levels and platelet activation markers compared with the control group. Rats in the HCS group had a significant decrease in lipid levels and downregulation in the number of platelets expressing surface P-selectin, CD40, and CD40L compared with the HC group. We observed decreased fatty streak formations in aortas in HCS rats. A positive correlation was found for platelet activation markers and atherosclerotic fatty streak formations. Regression analysis revealed that the predictor of atherosclerosis was CD40L. Our study suggests that in a rat hypercholesterolemic model, statin treatment may influence the CD40-CD40L dyad, and that this effect is parallelled by a suppression of progression of atherosclerotic plaque formation.

Effects of lisinopril on NMDA receptor subunits 2A and 2B levels in the hippocampus of rats with L-NAME-induced hypertension.

Hypertension is major risk factor leading to cerebrovascular pathologies. N-methyl D-aspartate receptors (NMDARs) and renin-angiotensin system are involved in neuronal plasticity, as well as cognitive functions in the hippocampus. In this study, we examined the effects of lisinopril, an ACE inhibitor, on the levels of hippocampal NMDAR subunits; NR2A and NR2B in L-NAME (N(ε)-nitro-L-arginine Methyl Ester)-induced hypertensive rats. In addition, malondialdehyde (MDA) levels were measured as a marker for lipid peroxidation. Compared with the control group, the MDA level was significantly increased after 8 weeks in the L-NAME-treated group. Rats treated with lisinopril and L-NAME plus lisinopril were found to have significantly decreased hippocampal MDA levels. Regarding the hippocampal concentrations of NR2A and NR2B, there were no statistically significant differences between groups. We demonstrated that lisinopril treatment has no direct regulatory effect on the levels of NR2A and NR2B in the rat hippocampus. Our results showed that Lisinopril could act as an antioxidant agent against hypertension-induced oxidative stress in rat hippocampus. The findings support that the use of lisinopril may offer a good alternative in the treatment of hypertension by reducing not only blood pressure but also prevent hypertensive complications in the brain.

Serum vitronectin levels in patients with Behçet's disease.

BACKGROUND/AIMS: To determine serum vitronectin levels in Behçet patients with and without ocular involvement, and to evaluate the relationship between vitronectin concentrations and clinical manifestations of Behçet's disease (BD). METHODS: Sixty-five patients with BD and 21 control subjects were included. All patients were queried for the clinical manifestations of BD. Serum vitronectin concentrations were determined by using in vitro enzyme immunoassay kits. RESULTS: Serum vitronectin levels between the patients and the control subjects were not different. There was no statistically significant difference between vitronectin levels in Behçet patients with and without ocular involvement. No correlation was found between vitronectin concentrations and clinical manifestations. CONCLUSION: This is the first study evaluating vitronectin levels in Behçet patients. Further studies involving larger numbers of subjects would be useful to improve our understanding of the functions of vitronectin in BD.

Effects of chronic scopolamine administration on spatial working memory and hippocampal receptors related to learning.

Scopolamine has been used in neuropsychopharmacology as a standard drug that leads to symptoms mimicking cognitive deficits seen during the aging process in healthy humans and animals. Scopolamine is known to be a nonselective muscarinic receptor blocker, but its chronic effect on the expression of certain hippocampal receptors is not clear. The aim of the present study was to determine the effect of chronic scopolamine administration on hippocampal receptor expression and spatial working memory in two different learning tasks, the water maze and the eight-arm radial maze. Male rats (8-12 months) were trained in both tasks. Subsequently, different groups received physiological saline or 0.1, 0.8, or 2 mg/kg scopolamine hydrobromide, respectively, for 15 days. After drug administration, the rats were retested for both tasks, and hippocampal expressions of NR2A, NR2B, nAChRα7, and mAChRM1 receptors were assessed by western blotting analysis. In both tasks, the spatial working memory was decreased dose dependently in all groups compared with the control group. In terms of receptor expressions, 0.8 and 2 mg/kg scopolamine administration significantly decreased NR2A protein expression, which corroborates suggestions of an interaction between cholinergic and glutamatergic receptors in the hippocampus.

The protective effect of adrenomedullin on renal injury, in a model of abdominal aorta cross-clamping.

Renal injury induced by aortic ischemia-reperfusion (IR) is an important factor in the development of postoperative acute renal failure following abdominal aortic surgery. The aim of this study was to examine the effect of adrenomedullin (AM) on kidney injury induced by infrarenal abdominal aortic IR in rats. Thirty-two Wistar Albino rats were randomized into four groups (eight per group) as follows: Control group, IR group (120-minute ischemia and 120-minute reperfusion), IR + AM group (a bolus intravenously of 0.05 µg/kg/min AM), and control + AM group. At the end of the experiment, blood and kidney tissue specimens were obtained for biochemical analysis. Immunohistological evaluation of the rat kidney tissues was also done. IR significantly increased (p < 0.05 vs control group) and AM significantly decreased (p < 0.05 vs. IR group) all of the biochemical parameters. Immunohistological evaluation showed that AM attenuated morphological changes as apoptosis associated with kidney injury. The results of this study indicate that AM attenuates both biochemically and immunohistopathologically kidney injury induced by aortic IR in rats.

The effect of cadmium toxicity on renal nitric oxide synthase isoenzymes.

The aim of this study was to assess the cadmium (Cd) toxicity on renal nitric oxide synthase (NOS) isoenzymes. The study was carried out on 18 inbred male (Cd group: 10 and control group: 8) Wistar rats. Cd group received drinking water containing 15 mg/L Cd for 30 days; and at the end of the 30 days, plasma Cd was analysed. One kidney was snap frozen to assess the endothelial NOS (eNOS), inducible NOS (iNOS) and neuronal NOS (nNOS) expressions by Western blot analyses, and the other kidney was preserved for histopathological examination. Plasma Cd levels were significantly elevated in the Cd group. The Western blot analyses found higher levels of eNOS, iNOS and nNOS in the Cd group but only eNOS and nNOS levels were statistically significant. There was no difference in pathological assessment of the renal tissues. Cd toxicity increases NOS isoenzyme levels and may affect renal physiology.

Calorie restriction modulates hippocampal NMDA receptors in diet-induced obese rats.

Calorie restriction (CR) has attracted increased interest since CR enhances lifespan and alters age-related decline in hippocampal-dependent cognitive functions. Obesity is associated with poor neurocognitive outcome including impaired hippocampal synaptic plasticity and cognitive abilities such as learning and memory. N-Methyl-D-aspartate receptors (NMDARs) are linked to hippocampal-dependent learning and memory, which may be stabilized by CR. In the present study, we aimed to establish the effects of CR on NMDARs in CA1 region of hippocampus in obese and non-obese rats. In addition, malondialdehyde (MDA) levels were determined as a marker for lipid peroxidation (LPO) in hippocampus. Four groups were constituted as control group (C, n = 9), obese group (OB, n = 10), obese calorie-restricted group (OCR, n = 9), and non-obese calorie-restricted group (NCR, n = 10). OCR and NCR were fed with a 60% CR diet for 10 weeks. After 10 weeks of CR, the MDA levels significantly decreased in the calorie-restricted groups. Obesity caused significant decreases in NR2A and NR2B subunit expressions in the hippocampus. The hippocampal NR2A and NR2B levels significantly increased in the OCR group compared with the OB group (P < 0.05). In contrast, the hippocampal NR2A and NR2B levels significantly decreased in the NCR group compared with the C group (P < 0.05). Oxidative stress can be prevented by CR, and these data may provide a molecular and cellular mechanism by which CR may regulate NMDAR-mediated response against obesity-induced changes in the hippocampus.

Effects of ammonia and allopurinol on rat hippocampal NMDA receptors.

Ammonia is considered to be the main agent responsible for hepatic encephalopathy which progressively leads to altered mental status. N-methyl-D-aspartate (NMDA) is an ionotropic glutamate receptor, which is involved in synaptogenesis, memory and neurotoxicity. The aim of this study was to investigate the effects of ammonia intoxication and allopurinol, a xanthine oxidase (XO) inhibitor, on NMDA receptor subunits, NR2A and NR2B, in the hippocampus of rats. Thirty-six male rats were divided into three groups (n = 12/group) as follows: (1)control group (phosphate buffered saline (PBS) solution); (2)ammonia group (ammonium acetate, 2.5 mmol/kg), (3)ammonia + allopurinol group (ammonium acetate, 2.5 mmol/kg, allopurinol, 50 mg/kg). Each rat received intraperitoneal injection for 28 days. Western Blotting technique was used for detecting NR2A and NR2B expressions. Both NR2A and NR2B subunit expressions decreased 27 and 11%, respectively, in ammonia group with respect to the control group. Ammonium acetate decreased significantly in NR2A subunit expressions in the hippocampus (p < 0.01). Administration of ammonia + allopurinol caused statistically significant increases in NR2A subunit expressions compared to the ammonia group (p < 0.001). The down-regulation of NMDA receptors caused by ammonium acetate suggest that these receptors may play role in the process of hepatic encephalopathy and using allopurinol may have some protective effects in ammonia toxicity.

New volatile anesthetic, desflurane, reduces vitamin E level in blood of operative patients via oxidative stress.

It has been well known that some volatile anesthetic agents produce oxidative stress. Desflurane as a new volatile agent might have limited oxidative toxic effect because it is relatively a new short-acting anesthetic characterized by a short duration of action and a quick postanesthetic recovery. We investigated effect of desflurane on serum glutathione peroxidase (GSH-Px), lipid peroxidation (LP), vitamin E, and erythrocyte superoxide dismutase (SOD) values in patients. Fifteen adult patients are scheduled for elective surgery, ASA I or II physical status. Tidal volume and ventilation frequency were kept unchanged during the operation. Baseline values in venous blood samples were preoperatively taken and blood was also taken postoperatively at the 1st and the 12th hours of desflurane exposure. LP levels were significantly (p < 0.05) higher postoperatively at 1st hour than in preoperative values while alpha-tocopherol concentration was significantly (p < 0.001) lower in postoperative period at 1st hour than in preoperative period. Erythrocyte SOD and serum GSH-Px activities did not differ between pre- and postoperative periods. In conclusion, we observed that desflurane produced oxidative stress by decreasing alpha-tocopherol levels. Use of vitamin E may be possible to reduce the oxidative effect of desflurane.

Recurrent implantation failure is associated with increased levels of fetuin-A/alpha2-Heremans-Schmid-glycoprotein.

OBJECTIVE: Recurrent implantation failure is defined as the absence of implantation, after two or three consecutive cycles of in-vitro fertilization (IVF), intracytoplasmic sperm injection or frozen embryo replacement. Human fetuin-A/alpha2-Heremans-Schmid-glycoprotein is a plasma protein secreted by the liver that modulates insulin action in adipocytes. Increased fetuin-A promotes adipocyte dysfunction which results in decreased adiponectin and increased fatty acids and inflammatory cytokines. Fatty acids and inflammatory cytokines were previously reported in implantation failure. Also, fetuin-A inhibits receptor tyrosine kinase activity in trophoblast growth factors which decrease trophoblast viability and invasion. In this study, we aimed to find the association between fetuin-A and implantation failure. STUDY DESIGN: A total of 78 women were included in this case-control study. Serum fetuin-A concentrations were measured in 42 women with recurrent IVF failure and 36 healthy women with regular cycles. RESULTS: The mean serum fetuin-A levels of implantation failure and control women were 257.77 ± 32.18 and 219.59 ± 48.86 respectively with a p-value <0.001 (independent samples t-test). Our results showed a statistically significant difference between serum fetuin-A levels of implantation failure women and controls. CONCLUSION: So far reasons for implantation failure are only partially understood. The current study reveals the association between implantation failure and fetuin-A. Further studies with large population sizes are needed to investigate whether fetuin-A can be used as a marker before controlled ovarian stimulation began or regulation of fetuin-A levels with treatment or lifestyle interventions can improve implantation success.

Lipid peroxidation level and antioxidant enzyme activities in the blood of patients with acute and chronic fascioliasis.

OBJECTIVE: In this study, we investigated the relationship between fascioliasis and serum malondialdehyde (MDA) levels, superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx) activities. We also investigated whether there are significant differences in MDA levels and antioxidant enzymatic activities between acute and chronic fascioliasis. METHODS: Forty fascioliasis patients who were diagnosed by ES-ELISA positivity were included in this study. The patients were classified as 18 with acute and 22 with chronic fascioliasis. RESULTS: In patients with fascioliasis, levels of MDA were statistically higher and erythrocyte SOD and GPx activities were statistically lower than in healthy controls. MDA levels were found to be higher in patients with acute fascioliasis than in patients with chronic fascioliasis although MDA levels were significantly higher in patients with chronic fascioliasis than in controls. There was no statistically significant difference between the two groups for the antioxidant enzyme activities. CONCLUSION: The results of this study may indicate that fascioliasis produces specific effects on the antioxidant defense mechanisms due to its inflammatory character. Our results also allow us to suggest that oxidative stress has an important role in the pathogenesis of fascioliasis and the persistence of this oxidative stress can be one of the underlying factors in the pathogenesis of the chronic disease.

Protective effects of erdosteine and vitamins C and E combination on ischemia-reperfusion-induced lung oxidative stress and plasma copper and zinc levels in a rat hind limb model.

The aim of this study was to investigate the protective effects of erdosteine and vitamins C and E (VCE) on the lungs after performing hind limb ischemia-reperfusion (I/R) by assessing oxidative stress, plasma copper (Cu), and zinc (Zn) analysis. The animals were divided randomly into four groups as nine rats each as follows: control, I/R, I/R plus erdosteine, and I/R plus VCE combination. I/R period for 60 min was performed on the both hind limbs of all the rats in the groups of I/R, erdosteine with I/R, VCE with I/R allowing 120 min of reperfusion. The animals received orally erdosteine one time in a day and 3 days before I/R in the erdosteine group. In the VCE group, the animals VCE combination received one time in a day and 3 days before I/R, although placebo was given to control and I/R group animals. Lung lipid peroxidation (malondialdehyde [MDA]) level, superoxide dismutase (SOD), and catalase activities were increased, although lung glutathione (GSH) and plasma Zn levels decreased in I/R group in lung tissue compared with the control group. Serum MDA level, creatine kinase, and lactate dehydrogenase activities were increased in I/R group compared with the control. Lung MDA and plasma Zn levels and lung SOD activity were decreased by erdosteine administration, whereas lung GSH levels after I/R increased. The plasma Zn levels and lung SOD activity were decreased by VCE administration, although the plasma Cu and lung GSH levels increased after I/R. In conclusion, erdosteine has an antioxidant role on the values in the rat model, and it has more protective affect than in VCE in attenuating I/R-induced lung injury in rats.

[The relationship between viral load and malondialdehyde and antioxidant enzymes in patients with hepatitis C virus infection]. / Hepatit C virus enfeksiyonu olan hastalarda viral yük ile malondialdehid ve antioksidan enzimlerin iliskisi.

Oxidative stress is known to participate in the pathogenesis of HCV infection. The aim of this study was to investigate the relationship between antioxidant defence state, malondialdehyde (MDA) and viral load in patients with hepatitis C virus (HCV) infection. Fifty patients who were positive for serological and molecular markers of HCV infection, and 40 healthy volunteers as control group were included in the study. The patients were classified according to their viral loads, and the catalase, superoxide dismutase (SOD) and glutathione peroxidase (GP) activities of erythrocytes and MDA in sera of all groups were measured. These substances were detected by using the methods described by Aebi, Woolliams et al, Paglia and Valentine, Draper and Hadley, respectively. As a result, decrease in SOD and GP levels and increase in MDA and catalase levels have been detected in HCV infected patients when compared with healthy controls, and these differences were statistically significant (p<0.05, t=19.3),except for catalase. However, there were no statistically significant difference among groups classified according to viral load (p>0.05, t=1.6). Although our data in HCV infected patients demonstrate a significant decrease in antioxidant enzyme levels and a significant increase in MDA levels, a marker of oxidative stress, it could not possible to make a correlation between these differences and the viral loads of patients.

Greater Efficiency Observed 12 Months Post-Implementation of an Automatic Tube Sorting and Registration System in a Core Laboratory.

BACKGROUND: Sample classification and registration have been recognized as important and time-consuming processes in laboratories. There is increasing pressure on laboratories to automate processes due to intense workload and reduce manual procedures and errors. The aim of the present study was to evaluate the positive effects of an automatic tube registration and sorting system on specimen processing. METHODS: An automatic tube registration and sorting system (HCTS2000 MK2, m-u-t AG, Wedel, Germany) was evaluated. Turnaround time (TAT), rate of sample rejection and unrealized tests were examined 12 months pre- and post-implementation of the automatic tube sorting and registration system. RESULTS: The mean TAT of routine chemistry immunoassay, complete blood cell count (CBC) and coagulation samples were significantly improved (P<0.001). The number of rejected samples and unrealized tests was insignificantly decreased post-implementation of the system (0.4% to 0.2% and 4.5% to 1.4%, respectively) (P>0.05). CONCLUSIONS: By reducing delays and errors in the preanalytical processing and sorting of samples, significant improvements in specimen processing were observed after implementation of the system. These results suggest that an automatic tube registration and sorting system may also be used to improve specimen processing in a higher-volume core laboratory.

Vascular wall damage in rats induced by organophosphorus insecticide methidathion.

We have examined the effect of subchronic methidathion (MD) administration on vascular wall damage. The experimental groups were: control group and rats treated with 5 mg/kg MD. The MD group was given MD by gavage for 5 days a week for 4 weeks at a dose level of 5 mg/kg per day by using corn oil as the vehicle. The levels of malondialdehyde (MDA) were determined in the vascular tissue. Histopathological examination was examined in the thoracic aortic tissue. The levels of MDA were increased in the MD group compared with the control group (P < 0.01). In the MD group, subchronic MD administration led to the irregulation, prominent breaks and fragmentation of the elastic fibers were located in the media of aortic wall. In conclusion, it is likely that subchronic MD administration caused vascular wall damage and, in addition, lipid peroxidation may be one of the molecular mechanisms involved in MD-induced vascular toxicity.

Nitric oxide level in the nasal and sinus mucosa after exposure to electromagnetic field.

OBJECTIVE: The purpose of this study was to examine the changes in nitric oxide (NO) level in the nasal and paranasal sinus mucosa after exposure radiofrequency electromagnetic fields (EMF). STUDY DESIGN AND SETTING: Thirty male Sprague-Dawley rats were randomly grouped as follows: EMF group (group I; n, 10), EMF group in which melatonin received (group II; n, 10) and the control (sham operated) group (group III; n, 10). Groups I and II were exposed to a 900 MHz. Oral melatonin was given in group II. Control rats (group III) were also placed in the tube as the exposure groups, but without exposure to EMF. At the end of 2 weeks, the rats were sacrificed, and the nasal and paranasal sinus mucosa dissected. NO was measured in nasal and paranasal mucosa. RESULTS: The nasal and paranasal sinus mucosa NO levels of group I were significantly higher than those of the control group (group III) ( P < 0.05). However, there was no statistically significant difference between group II and the control group (group III) regarding NO output ( P > 0.05). CONCLUSION: Exposure to EMF released by mobile phones (900 MHz) increase NO levels in the sinus and nasal mucosa. SIGNIFICANCE: Increased NO levels may act as a defense mechanism and presumably related to tissue damage. In addition, melatonin may have beneficial effect to prevent these changes in the mucosa.

Biological and morphological effects on the reproductive organ of rats after exposure to electromagnetic field.

OBJECTIVE: The biological effect of electromagnetic field (EMF) emitted from mobile phones is a current debate and still a controversial issue. Therefore, little is known on the possible adverse effects on reproduction as mobile phone bio-effects are only a very recent concern. The aim of this experimental study was to determine the biological and morphological effects of 900 MHz radiofrequency (RF) EMF on rat testes. METHODS: The study was performed in the Physiology and Histology Research Laboratories of Süleyman Demirel University, Faculty of Medicine, Isparta, Turkey in May 2004. Twenty adult male Sprague-Dawley rats weighing 270-320 gm were randomized into 2 groups of 10 animals: Group I (control group) was not exposed to EMF and Group II (EMF group) was exposed to 30 minutes per day, 5 days a week for 4 weeks to 900 MHz EMF. Testes tissues were submitted for histologic and morphologic examination. Testicular biopsy score count and the percentage of interstitial tissue to the entire testicular tissue were registered. Serum testosterone, plasma luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels were assayed biochemically. RESULTS: The weight of testes, testicular biopsy score count and the percentage of interstitial tissue to the entire testicular tissue were not significantly different in EMF group compared to the control group. However, the diameter of the seminiferous tubules and the mean height of the germinal epithelium were significantly decreased in EMF group (p<0.05). There was a significant decrease in serum total testosterone level in EMF group (p<0.05). Therefore, there was an insignificant decrease in plasma LH and FSH levels in EMF group compared to the control group (p>0.05). CONCLUSION: The biological and morphological effects resulting from 900 MHz RF EMF exposure lends no support to suggestions of adverse effect on spermatogenesis, and on germinal epithelium. Therefore, testicular morphologic alterations may possibly be due to hormonal changes.