Extremely Low-Frequency Magnetic Field Decreased Calcium,Zinc and Magnesium Levels in Costa of Rat

Electromagnetic field (EMF) can affect cells due to biochemical change followed by a change in level of ions trafficking through membrane. We aimed to investigate possible changes in some elements in costa of rats exposed to long-term extremely low-frequency magnetic field (ELF-MF). Rats were exposed to 100 and 500 μT ELF-MF, which are the safety standards of public and occupational exposure for 2 h/day during 10 months. At the end of the exposure period, the samples of costa were taken from the rats exposed to ELF-MF and sham. The levels of elements were measured by using atomic absorption spectrophotometry (AAS) and ultraviolet (UV) spectrophotometry. Ca levels decreased in the ELF-500 exposure group in comparison to sham group (p < 0.05). Statistically significant decrease was found in Mg levels in the ELF-500 exposure group in comparison to sham and ELF-100 exposure groups (p < 0.05). Zn levels were found to be lower in the ELF-500 exposure group than those in the sham and ELF-100 exposure groups (p < 0.05). No significant differences were determined between groups in terms of the levels of P, Cu and Fe. In conclusion, it can be maintained that long-term ELF-MF exposure can affect the chemical structure and metabolism of bone by changing the levels of some important elements such as Ca, Zn and Mg in rats.     

Effects of Extremely Low-Frequency Magnetic Field on Caspase Activities and Oxidative Stress Values in Rat Brain

This study was aimed to investigate the effect of extremely low-frequency magnetic field (ELF-MF) on apoptosis and oxidative stress values in the brain of rat. Rats were exposed to 100 and 500 µT ELF-MF, which are the safety standards of public and occupational exposure for 2 h/day for 10 months. Brain tissues were immunohistochemically stained for the active (cleaved) caspase-3 in order to measure the apoptotic index by a semi-quantitative scoring system. In addition, the levels of catalase (CAT), malondialdehyde (MDA), myeloperoxidase (MPO), total antioxidative capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) were measured in rat brain. Final score of apoptosis and MPO activity were not significantly different between the groups. CAT activity decreased in both exposure groups (p?<?0.05), while TAC was found to be lower in ELF 500 group than those in ELF-100 and sham groups (p?<?0.05). MDA, TOS, and OSI values were found to be higher in ELF-500 group than those in ELF-100 and sham groups (p?<?0.05). In conclusion, apoptosis was not changed by long-term ELF-MF exposure, while both 100 and 500 µT ELF-MF exposure induced toxic effect in the rat brain by increasing oxidative stress and diminishing antioxidant defense system.     

Alteration of nitric oxide production in rats exposed to a prolonged, extremely low-frequency magnetic field

The purpose of this study is to investigate the possible effect of an extremely low-frequency magnetic field (ELF-MF) on nitric oxide (NO) level. In this study, 27 male Sprague-Dawley rats were used. The rats were divided into three groups: two experimental and one control (sham-exposed). The first and second experimental group (n = 10) were exposed to 100 microT and 500 microT ELF-MF during 10 months, 2 h a day, respectively, and the third (n = 7) group was treated like an experimental group except for ELF-MF exposure in methacrylate boxes. After ELF-MF and sham exposure, serum nitrite levels were measured by Griess reaction. A significant reduction was observed in nitrite levels among the first and second experimental groups of rats and sham-exposed rats after exposure for 10 months, 2 h a day, to ELF-MF of 100 and 500 microT (p < 0.01). These results suggest that prolonged ELF-MF exposure at intensities of exposure limits, determined by ICNIRP for public and occupational, may reduce NO production probably affected by NO generation pathways.     

Deterioration of Bone Quality by Streptozotocin (STZ)-Induced Type 2 Diabetes Mellitus in Rats

Patients with diabetes mellitus (DM) have various skeletal disorders and bone quality can be impaired in DM leading to fractures. Wistar albino male rats (270?C300?g; n?=?16) were assigned randomly to nondiabetic and diabetic rats (single dose intravenous injection of 45?mg/kg streptozotocin). All rats in each group were perpetuated for 8?weeks, and blood glucose levels as well as body weights were measured once weekly. Biomechanical measurements were performed at the mid-diaphysis of the left femur with tensile test. Extrinsic and intrinsic properties were measured or calculated. Bone mineral density (BMD) was also evaluated and measured by dual-energy X-ray absorptiometry. Cross-sectional area of the femoral shaft was evaluated by computerized tomography. Blood glucose levels in diabetic rats were significantly increased compared to that of the nondiabetic rats, while the body and femur weights were decreased (P?<?0.05). In respect to the BMD, cross-sectional area and femur length, there were no statistically significant differences between the nondiabetic and diabetic rats (P?>?0.05). The maximum load, ultimate stress, and toughness endpoints in diabetic rats were significantly decreased compared to that of the nondiabetics (P?<?0.05). There were no statistically significant differences between the nondiabetic and diabetic rats with regard to the displacement and stiffness (P?>?0.05). Femurs of diabetic rats had less absorbed energy than that in nondiabetics (P?<?0.05). Ultimate strain was lower in diabetic rats than that in nondiabetics, while the elastic modulus was higher (P?>?0.05). The bone quality of rats is decreased by streptozotocin-induced type 2 diabetes mellitus.     

Effect of long-term exposure of 2.4 GHz radiofrequency radiation emitted from Wi-Fi equipment on testes functions

Abstract

The aim of this study was to investigate long-term effects of radiofrequency radiation (RFR) emitted from a Wireless Fidelity (Wi-Fi) system on testes. The study was carried out on 16 Wistar Albino adult male rats by dividing them into two groups such as sham (n: 8) and exposure (n: 8). Rats in the exposure group were exposed to 2.4?GHz RFR radiation for 24?h/d during 12 months (1 year). The same procedure was applied to the rats in the sham control group except the Wi-Fi system was turned off. Immediately after the last exposure, rats were sacrificed and reproductive organs were removed. Motility (%), concentration (×10⁶/mL), tail defects (%), head defects (%) and total morphologic defects (%) of sperms and weight of testes (g), left epididymis (g), prostate (g), seminal vesicles (g) were determined. Seminiferous tubules diameter (μm) and tunica albuginea thickness (μm) were also measured. However, the results were evaluated by using Johnsen’s score. Head defects increased in the exposure group (p?<?0.05) while weight of the epididymis and seminal vesicles, seminiferous tubules diameter and tunica albuginea thickness were decreased in the exposure group (p?<?0.01, p?<?0.001, p?<?0.0001). However, other alterations of other parameters were not found significant (p?>?0.05). In conclusion, we observed that long-term exposure of 2.4?GHz RF emitted from Wi-Fi (2420?μW/kg, 1?g average) affects some of the reproductive parameters of male rats. We suggest Wi-Fi users to avoid long-term exposure of RF emissions from Wi-Fi equipment.     

Effects of Aluminum and Extremely Low Frequency Electromagnetic Radiation on Oxidative Stress and Memory in Brain of Mice

This study was aimed to investigate the effect of aluminum and extremely low-frequency magnetic fields (ELF-MF) on oxidative stress and memory of SPF Kunming mice. Sixty male SPF Kunming mice were divided randomly into four groups: control group, ELF-MF group (2 mT, 4 h/day), load aluminum group (200 mg aluminum/kg, 0.1 ml/10 g), and ELF-MF?+?aluminum group (2 mT, 4 h/day, 200 mg aluminum/kg). After 8 weeks of treatment, the mice of three experiment groups (ELF-MF group, load aluminum group, and ELF-MF?+?aluminum group) exhibited firstly the learning memory impairment, appearing that the escaping latency to the platform was prolonged and percentage in the platform quadrant was reduced in the Morris water maze (MWM) task. Secondly are the pathologic abnormalities including neuronal cell loss and overexpression of phosphorylated tau protein in the hippocampus and cerebral cortex. On the other hand, the markers of oxidative stress were determined in mice brain and serum. The results showed a statistically significant decrease in superoxide dismutase activity and increase in the levels of malondialdehyde in the ELF-MF group (P?<?0.05 or P?<?0.01), load aluminum group (P?<?0.01), and ELF-MF?+?aluminum group (P?<?0.01). However, the treatment with ELF-MF?+?aluminum induced no more damage than ELF-MF and aluminum did, respectively. In conclusion, both aluminum and ELF-MF could impact on learning memory and pro-oxidative function in Kunming mice. However, there was no evidence of any association between ELF-MF exposure with aluminum loading.     

Rats avoid exposure to HVdc electric fields: A dose response study

Rats, given the choice, avoid exposure to alternating current (ac) 60-Hz electric fields at intensities ? 75 kV/m. This study investigated the generality of this behavior by studying the response of rats when exposed to high voltage direct current (HV dc) electric fields. Three hundred eighty male Long Evans rats were studied in 9 experiments with 40 rats per experiment and in one experiment with 20 rats to determine 1) if rats avoid exposure to HVdc electric fields of varying field strengths, and 2) if avoidance did occur, what role, if any, the concentration of air ions would have on the avoidance behavior. In all experiments a three-compartment glass shuttlebox was used; either the left or right compartment could be exposed to a combination of HVdc electric fields and air ions while the other compartment remained sham-exposed. The third, center compartment was a transition zone between exposure and sham-exposure. In each experiment, the rats were individually assessed in 1-h sessions where half of the rats (n = 20) had the choice to locomote between the two sides being exposed or sham-exposed, while the other half of the rats'(n = 20) were sham-exposed regardless of their location, except in one experiment where there was no sham-exposed group. The exposure levels for the first six experiments were 80, 55, 42.5, 30, ?36, and ?55 kV/m, respectively. The air ion concentration was constant at 1.4 × 10⁶ ions/cc for the four positive exposure levels and ?1.4 × 10⁶ ions/cc for the two negative exposure levels. Rats having a choice between exposure and non-exposure relative to always sham-exposed control animals significantly reduced the amount of time spent on the exposed side at 80kV/m (P < .002) as they did at both 55 and ?55 kV/m (P < .005). No significant differences between groups were observed at 42.5, 30, or -36 kV/m. To determine what role the air ion concentration might have had on the avoidance behavior at field strengths of 55 kV/m or greater, four additional experiments were conducted. The HVdc exposure level was held constant at either ?55 kV/m (for three experiments) or -55 kV/m (for 1 experiment) while the air ion concentration was varied between experiments at 2.5 × 10⁵ ions/cc, 1.0 × 10⁴ for two of the experiments and was below the measurement limit (< ± 2 × 10³ ions/cc) for the other two experiments at 55 and ?55 kV/m. The exposed rats significantly reduced the amount of time spent on the exposed side at 55 and ?55 kV/m, relative to the sham-exposed rats regardless of air ion concentration (all at P < .005). Thus, HVdc electric fields of ? + or ?55 kV/m are sufficient to produce avoidance behavior in rats. Positive or negative air ion concentrations were not significant factors in these avoidance outcomes. © 1993 Wiley-Liss, Inc.     

Does granulocyte colony stimulating factor have protective effects against carbon monoxide-induced apoptosis?

Carbon monoxide (CO) produced by incomplete combustion of hydrocarbons, has many toxic effects on different organs, especially the heart and brain that have greater demands for oxygen. The present study aimed to evaluate the protective effects of granulocyte colony stimulating factor (G-CSF) on apoptosis after CO poisoning in rats. Male Wistar rats were exposed to CO 1500 or 3000 ppm for 60 min. Single and multiple doses of G-CSF (10, 50, and 100 μg/kg) were administered to animals. After CO poisoning, carboxyhemoglobin concentration was measured, apoptotic cells were evaluated by TUNEL assay and caspase 3 activity was determined by immunofluorescence. Blood levels of carboxyhemoglobin significantly increased following exposure to both 1500 and 3000 ppm concentrations of CO. However, carboxyhemoglobin levels were significantly higher following exposure to CO 3000 ppm compared to CO 1500 ppm (p?<?0.05). Differences in caspase 3 activity between G-CSF and control groups were significant and G-CSF could decrease apoptosis following CO 3000 ppm poisoning (p?<?0.001). TUNEL assay showed that in rats treat with 5 doses of G-CSF 100 μg/kg, apoptosis was significantly ameliorated compared to control rats and sham (rats that were not exposed to CO) group (p?<?0.05). Concerning caspase 3 activity and apoptosis rate, the best results were found in rats exposed to 3000 ppm and treated with G-CSF 100 μg/kg. In this study, we confirmed that CO poisoning leads to cardiomyocytes apoptosis which could be significantly reduced by G-CSF treatment.     

Extremely Low-Frequency Magnetic Exposure Appears to Have No Effect on Pathogenesis of Alzheimer’s Disease in Aluminum-Overloaded Rat

Objective

Extremely low-frequency magnetic field (ELF-MF) has been reported to be of potential pathogenetic relevance to Alzheimer''s disease (AD) for years. However, evidence confirming this function remains inconclusive. Chronic Al treatment has been identified as a contributing factor to cognitive function impairment in AD. This study aims to examine whether or not ELF-MF and Al have synergistic effects toward AD pathogenesis by investigating the effects of ELF-MF with or without chronic Al treatment on SD rats.

Methods

Sprague-Dawley (SD) rats were subjected one of the following treatments: sham (control group), oral Al (Al group), ELF-MF (100 µT at 50 Hz) with oral Al (MF+Al group), or ELF-MF (100 µT at 50 Hz) without oral Al (MF group).

Results

After 12 wk of treatment, oral Al treatment groups (Al and MF+Al groups) showed learning and memory impairment as well as morphological hallmarks, including neuronal cell loss and high density of amyloid-β (Aβ) in the hippocampus and cerebral cortex. ELF-MF without Al treatment showed no significant effect on AD pathogenesis. ELF-MF+Al treatment induced no more damage than Al treatment did.

Conclusions

Our results showed no evidence of any association between ELF-MF exposure (100 µT at 50 Hz) and AD, and ELF-MF exposure does not influence the pathogenesis of AD induced by Al overload.     

Sudden death in epileptic rats exposed to nocturnal magnetic fields that simulate the shape and the intensity of sudden changes in geomagnetic activity: an experiment in response to Schnabel, Beblo and May

To test the hypothesis that sudden unexplained death (SUD) in some epileptic patients is related to geomagnetic activity we exposed rats in which limbic epilepsy had been induced to experimentally produced magnetic fields designed to simulate sudden storm commencements (SSCs). Prior studies with rats had shown that sudden death in groups of rats in which epilepsy had been induced months earlier was associated with the occurrence of SSCs and increased geomagnetic activity during the previous night. Schnabel et al. [(2000) Neurology 54:903–908) found no relationship between SUD in human patients and geomagnetic activity. A total of 96 rats were exposed to either 500, 50, 10–40 nT or sham (less than 10 nT) magnetic fields for 6 min every hour between midnight and 0800 hours (local time) for three successive nights. The shape of the complex, amplitude-modulated magnetic fields simulated the shape and structure of an average SSC. The rats were then seized with lithium and pilocarpine and the mortality was monitored. Whereas 10% of the rats that had been exposed to the sham field died within 24 h, 60% of the rats that had been exposed to the experimental magnetic fields simulating natural geomagnetic activity died (P<.001) during this period. These results suggest that correlational analyses between SUD in epileptic patients and increased geomagnetic activity can be simulated experimentally in epileptic rats and that potential mechanisms might be testable directly.     

Effect of exposure to 50 Hz magnetic field with or without insulin on blood–brain barrier permeability in streptozotocin‐induced diabetic rats

We investigated the effect of long‐term exposure to modulation magnetic field (MF), insulin, and their combination on blood–brain barrier (BBB) permeability in a diabetic rat model. Fifty‐three rats were randomly assigned to one of six groups: sham, exposed to no MF; MF, exposed to MF; diabetes mellitus (DM), DM induced with streptozotocin (STZ); DM plus MF (DMMF); DM plus insulin therapy (DMI); and DM plus insulin therapy plus MF (DMIMF). All the rats underwent Evans blue (EB) measurement to evaluate the BBB 30 days after the beginning of experiments. The rats in MF, DMMF, and DMIMF groups were exposed to MF (B = 5 mT) for 165 min every day for 30 days. Mean arterial blood pressure (MABP), body mass, and serum glucose level of the study rats were recorded. The extravasation of brain EB of the MF, DM, DMMF, DMI, and DMIMF groups was higher than that of the sham group and the extravasation of right hemisphere of the DMIMF group was highest (P < 0.05). The post‐procedure body mass of the sham and MF groups were significantly higher than those of the DM and DMMF groups (P < 0.05). In the DM, DMMF, DMI, and DMIMF groups, the baseline glucose was significantly lower than the post‐procedure glucose (P < 0.05). DM and MF increase BBB permeability; in combination, they cause more increase in BBB permeability, and insulin decreases their effect on BBB. Improved glucose metabolism may prevent body mass loss and the hypoglycemic effect of MF. DM increases MABP but MF causes no additional effect. Bioelectromagnetics 31:262–269, 2010. © 2009 Wiley‐Liss, Inc.     

Decreased α1-Adrenergic Receptor Binding in the Cerebral Cortex and Brain Stem during Pancreatic Regeneration in Rats

The purpose of this study was to investigate the role of brain α₁-adrenergic receptor binding in the rat model of pancreatic regeneration using 60–70% pancreatectomy. The α₁-adrenergic receptors kinetics was studied in the cerebral cortex and brain stem of sham operated, 72 h pancreatectomised and 7 days pancreatectomised rats. Scatchard analysis with [³H]prazosin in cerebral cortex and brain stem showed a significant decrease (P < 0.01), (P < 0.05) in maximal binding (B _max) with a significant decrease (P < 0.001), (P < 0.01) in the K _d in 72 h pancreatectomised rats compared with sham respectively. Competition analysis in cerebral cortex and brain stem showed a shift in affinity during pancreatic regeneration. The sympathetic activity was decreased as indicated by the significantly decreased norepinephrine level in the plasma (P < 0.001), cerebral cortex (P < 0.01) and brain stem (P < 0.001) of 72 h pancreatectomised rats compared to sham. Thus, from our results it is suggested that the central α₁-adrenergic receptors have a functional role in the pancreatic regeneration mediated through the sympathetic pathway.     

CR3 (CD11b/CD18) activation of nasal neutrophils: a measure of upper airway endotoxin exposure

Inhaled endotoxin (lipopolysaccharide, LPS) initiates an inflammatory response and leads to the expression of CR3 (CD11b/CD18) receptors on polymorphonuclear leukocytes (PMNs). We determined if PMN activation in nasal lavage fluid (NLF) is a possible biomarker of occupational endotoxin exposure. Seven subjects exposed to endotoxin provided NLF samples that were split into three aliquots (negative control – 1?M nicotinamide; sham; positive control – 11 ηg of exogenous LPS) and PMN activation was measured using a chemiluminometer. Differences in mean PMN activation were apparent, negative control: 548?±?15.65 RLU 100 μl^?1; sham: 11469?±?2582 RLU 100 μl^?1; positive control: 42026?±?16659 RLU 100 μl (n?=?7; p <0.05). This technique shows promise as a diagnostic method for measuring upper airway LPS exposure.     

Quantitative changes in potassium,sodium, and calcium in the submaxillary salivary gland and blood serum of rats exposed to 2880-MHz microwave radiation

Na⁺, K⁺, and Ca²⁺ concentrations in the blood serum and submaxillary salivary gland (SSG) were investigated in adult, male rats exposed to 2880-MHz microwaves modulated with 1.5-μs pulses at a pulse repetition rate of 1000 Hz or in a hyperthermal environment. Rats were exposed, one at a time, for 30 min to microwaves producing a specific absorption rate (SAR) of: 4.2, 6.3,6.8,8.4, 10.8, or 12.6 W/kg, or were sham exposed under similar environmental conditions. In a second series, one group of rats was exposed singly for 15, 30, or 60 min to microwaves producing an SAR of 9.5 W/kg and other rats were exposed for similar periods at 40 °C; and 10 rats were sham exposed. Flame photometric analysis indicated that the thresholds of microwave radiation required to induce a change in Na⁺, K⁺, and Ca²⁺ concentrations in the salivary glands are 6.8, 6.8, and 6.3 W/kg, respectively. The directions of Na⁺, K⁺, and Ca²⁺ ion shifts in exposed rats' salivary glands are similar, whether affected by microwaves or hyperthermia. Greater changes in Na⁺ and K⁺ concentrations in SSG of rats exposed to microwaves for 15 and 30 min were found than in those exposed at 40 °C. On the other hand, exposure to hyperthermia at 40 °C or to microwaves for 1 h caused Na⁺ concentration to be increased by 68.7 and 59.5% and K⁺ concentration to be decreased by 29.6 and 21.7%, respectively.     

Effects of Astragalus membranaceus with Supplemental Calcium on Bone Mineral Density and Bone Metabolism in Calcium-Deficient Ovariectomized Rats

It has been reported that Astragalus membranaceus, an Asian traditional herb, has an estrogenic effect in vitro. To examine the possible role of A. membranaceus extract with supplemental calcium (Ca) on bone status in calcium-deficient (LCa) ovariectomized (OVX) rats, a total of 48 female rats were divided into six groups: (1) normal control, (2) sham operation with LCa (sham-LCa), (3) OVX with LCa (OVX-LCa), (4) A. membranaceus supplementation with OVX-LCa (OVX-MLCa), (5) Ca supplementation with OVX (OVX-Ca), and (6) A. membranaceus and Ca supplementation with OVX (OVX-MCa). A. membranaceus ethanol extract (500 mg/kg BW) and/or Ca (800 mg/kg BW) were administered orally for 8 weeks along with a Ca-deficient diet. Results revealed that Ca supplementation with or without A. membranaceus extract significantly improved bone mineral density, biomechanical strength, and ash weight of the femur and tibia in OVX rats. High Ca with A. membranaceus combination supplementation significantly increased the ash weight of the femur and tibia and decreased urinary Ca excretion compared with supplementation of Ca alone. Uterine weight was not changed by A. membranaceus administration in OVX rats. These results suggest that A. membranaceus extract combined with supplemental Ca may be more protective against the Ca loss of bone than A. membranaceus or supplementation of Ca alone in calcium-insufficient postmenopausal women.     

A mechanistic investigation into non-infarcted brain injury induced by cerebral artery microemboli

To establish a rat brain injury by non-infarction process model induced by cerebral artery microemboli which would be used to further explore the neural injury mechanisms of cerebral artery microemboli. Seventy-two Sprague–Dawley rats were randomly divided into the microemboli group and the sham group; 100 25–50 μm microemboli in 300 μl or the same amount of saline were injected into the left carotid artery, respectively. The severity of neuron damage was assessed 3 and 7 days after the operation, using haematoxylin-eosin (HE) staining and immunohistochemical staining for caspase-3. Immunohistochemical staining for CD11b and GFAP were used to quantitatively analyse hyperplasia and the activation of microglia and astrocytes. TNF-α expression was detected by using ELISA and the NF-κB expression was detected by employing Western blotting. The results of HE staining had shown that ischaemic infarct foci were not detected in either the microemboli group or sham group. Only a few apoptotic cells and a few cells with the positive expression of CD11b and GFAP were detected in the sham group. And compared with that of the sham group, the number of apoptotic cells and the positive expression of CD11b and GFAP in the microemboli group were significantly increased (P < 0.001). These parameters were also significantly increased 7 days after the operation compared to rats 3 days after surgery (P < 0.001). The expressions of TNF-α and NF-κB were significantly increased in the microemboli group (P < 0.001), and the increase of the expression of TNF-α and NF-κB on the 3 days was more significant compared to that of TNF-α and NF-κB on 7 days (P < 0.001). Injection of 25–50 μm microemboli at a dose of 100 microemboli in 300 μl into the carotid artery of rats did not result in cerebral infarction, but led to neuronal apoptosis, hyperplasia and activation of microglia and astrocytes. This leads us to conclude that TNF-α and NF-κB may play important roles in the pathogenesis of neuronal apoptosis induced by microemboli in the cerebral arteries.     

Decreased GABA<Subscript>A</Subscript> Receptor Function in the Brain Stem during Pancreatic Regeneration in Rats

Gamma amino butyric acid is a major inhibitory neurotransmitter in the central nervous system. In the present study we have investigated the alteration of GABA receptors in the brain stem of rats during pancreatic regeneration. Three groups of rats were used for the study: sham operated, 72 h and 7 days partially pancreatectomised. GABA was quantified by [³H]GABA receptor displacement method. GABA receptor kinetic parameters were studied by using the binding of [³H]GABA as ligand to the Triton X-100 treated membranes and displacement with unlabelled GABA. GABA_A receptor activity was studied by using the [³H]bicuculline and displacement with unlabelled bicuculline. GABA content significantly decreased (P < 0.001) in the brain stem during the regeneration of pancreas. The high affinity GABA receptor binding showed a significant decrease in B _max (P < 0.01) and K _d (P < 0.05) in 72 h and 7 days after partial pancreatectomy. [³H]bicuculline binding showed a significant decrease in B _max and K _d (P < 0.001) in 72 h pancreatectomised rats when compared with sham where as B _max and K _d reversed to near sham after 7 days of pancreatectomy. The results suggest that GABA through GABA receptors in brain stem has a regulatory role during active regeneration of pancreas which will have immense clinical significance in the treatment of diabetes.     

Effects of Remifemin Treatment on Bone Integrity and Remodeling in Rats with Ovariectomy-Induced Osteoporosis

This study aims to evaluate the effects of Remifemin (isopropanolic extract of Cimicifuga Racemosa) on postmenopausal osteoporosis. 120 female Sprague-Dawley rats were randomly assigned to four groups: sham surgery with vehicle, ovariectomy with vehicle, ovariectomy with estradiol valerate, or ovariectomy with Remifemin. Daily oral administrations of the vehicle, estradiol valerate, or Remifemin began 2 weeks after surgery and lasted to 4, 8, or 12 weeks. Ten rats in each group were sacrificed at each timestep with assessment of bone mineral density, trabecular bone structure, and biomechanical parameters of the femur and lumbar vertebra. Bone turnover markers were evaluated 12 weeks after surgery. Both drugs prevented bone density loss in the distal end of the femur and preserved the trabecular bone structure in both the lumbar vertebra and distal end of the femur following ovariectomy. Both drugs protected bone stiffness at the tested regions and reduced bone reabsorption in ovariectomized rats. The preventive effects of Remifemin against bone-loss can rival those of estradiol valerate if treatment duration is adequately extended. In conclusion, Remifemin may demonstrate equivalent effects to estradiol valerate in terms of preventing postmenopausal osteoporosis.     

Prenatal and early life arsenic exposure induced oxidative damage and altered activities and mRNA expressions of neurotransmitter metabolic enzymes in offspring rat brain

To better understand the effect of arsenic on central nervous system by prenatal and early life exposure, the oxidative stress and neurotransmitter metabolic enzymes were determined in offspring rats' brain cortex and hippocampus. Forty‐eight pregnant rats were randomly divided into four groups, each group was given free access to drinking water that contained 0, 10, 50, and 100 mg/L NaAsO₂ from gestation day 6 (GD 6) until postnatal day 42 (PND 42). Once pups were weaned, they started to drink the same arsenic (As)‐containing water as the dams. The level of malondialdehyde in 100 mg/L As‐exposed pup's brain on PND 0 and cortex on PND 28 and 42 were significantly higher than in the control group (p < 0.05). Reduced glutathione (GSH) levels showed a clear decreasing trend in pup's cortex and hippocampus on PND 42. Activity of acetylcholinesterase was significantly higher in 100 mg/L As‐exposed pup's hippocampus than in control group on PND 28 and 42. mRNA expression of glutamate decarboxylase (GAD₆₅ and GAD₆₇) in 100 mg/L As‐exposed pup's cortex or hippocampus on PND 28 and 42 were significantly higher than in control (p < 0.05). These alterations in the neurotransmitters and reduced antioxidant defence may lead to neurobehavioral and learning and memory changes in offspring rats. © 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 24:368–378, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.20349     

Effect of Mobile Phone Exposure on Apoptotic Glial Cells and Status of Oxidative Stress in Rat Brain

The aim of this study was to investigate the effects of mobile phone exposure on glial cells in brain. The study carried out on 31 Wistar Albino adult male rats. The rat heads in a carousel exposed to 900 MHz microwave. For the study group (n:14), rats exposed to the radiation 2h per day (7 days in a week) for 10 months. For the sham group (n:7), rats were placed into the carousel and the same procedure was applied except that the generator was turned off. For the cage control (n:10), nothing applied to rats in this group. In this study, rats were euthanized after 10 months of exposure periods and brains were removed.

Brain tissues were immunohistochemically stained for the active (cleaved) caspase-3, which is a well-known apoptosis marker, and p53. The expression of the proteins was evaluated by a semi-quantitative scoring system. However, total antioxidative capacity (TAC), catalase, total oxidant status (TOS), and oxidative stress index were measured in rat brain.

Final score for apoptosis in the exposed group was significantly lower than the sham (p < 0.001) and the cage control groups (p < 0.01). p53 was not significantly changed by the exposure (p > 0.05). The total antioxidant capacity and catalase in the experimental group was found higher than that in the sham group (p < 0.001, p < 0.05). In terms of the TOS and oxidative stress index, there was no statistically significant difference between exposure and sham groups (p > 0.05).

In conclusion, the final score for apoptosis, total antioxidant capacity and catalase in rat brain might be altered by 900 MHz radiation produced by a generator to represent exposure of global systems for mobile communication (GSM) cellular phones.