Relationship between cognition function and hippocampus structure after long-term microwave exposure / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To analyze the effects of long-term microwave exposure on hippocampal structure and function in the rat.</p><p><b>METHODS</b>Experiments were performed on 184 male Wistar rats (three exposure groups and a sham group). Microwaves were applied daily for 6 min over 1 month at average power densities of 2.5, 5, and 10 mW/cm2. Learning and memory abilities were assessed by Morris water maze. High performance liquid chromatography was used to detect neurotransmitter concentrations in the hippocampus. Hippocampal structures were observed by histopathological analysis.</p><p><b>RESULTS</b>Following long-term microwave exposure there was a significant decrease in learning and memory activity in the 7 d, 14 d, and 1 m in all three microwave exposure groups. Neurotransmitter concentrations of four amino acids (glutamate, aspartic acid, glycine, and gamma-aminobutyric acid) in hippocampus were increased in the 2.5 and 5 mW/cm2 groups and decreased in the 10 mW/cm2 group. There was evidence of neuronal degeneration and enlarged perivascular spaces in the hippocampus in the microwave exposure groups. Further, mitochondria became swollen and cristae were disordered. The rough endoplasmic reticulum exhibited sacculated distension and there was a decrease in the quantity of synaptic vesicles.</p><p><b>CONCLUSION</b>These data suggest that the hippocampus can be injured by long-term microwave exposure, which might result in impairment of cognitive function due to neurotransmitter disruption.</p>

Long-term microwave radiation affects male reproduction in rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the effect of long-term microwave radiation on male reproduction in rats.</p><p><b>METHODS</b>A total of 100 male Wistar rats were exposed to microwave radiation with average power density of 0, 2.5, 5 and 10 mW/cm2 for 4 weeks, 5 times a week and 6 minutes per time. Changes in serum testosterone, testicular index, histology and ultrastructure, and the percentage of teratospermia in the epididymis were observed dynamically at 6 h, 7 d, 14 d, 28 d and 60 d after the exposure.</p><p><b>RESULTS</b>There was a significant decrease in serum testosterone concentration at 28 d after microwave radiation at 2.5, 5 and 10 mW/cm2 ([10.20 +/- 4.31] ng/ml, [5.56 +/- 3.47] ng/ml and [7.53 +/- 4.54] ng/ml) and at 60 d at 10 mW/cm2 ( [15.95 +/- 9.54] ng/ml), as compared with the control group ([23.35 +/- 8.06] ng/ml and [31.40 +/- 9.56] ng/ml) (P < 0.05 or P < 0.01). No significant changes were found in the testis index at 6 h -60 d after microwave radiation at the three doses, but different degrees of degeneration, necrosis and shedding of spermatogenic cells, thinning of spermatogenic epithelia, and decrease or deletion of spermatozoa were observed, and more obvious at 28 d and 60 d. Swelling and cavitation of mitochondria in all spermatogenic cells, agglutination and margin translocation of nuclear chromatin in the spermatogonial and Leydig cells were seen at 7 d and 60 d after 5 mW/cm2 microwave radiation. The rate of teratospermia of the epididymis was increased, more obviously at 7 d after 2.5, 5 mW/cm2, 60 d after 5 mW/cm2, and 7 d, 28 d and 60 d after 10 mW/cm2 microwave radiation (P < 0.05 or P < 0.01).</p><p><b>CONCLUSION</b>Long-term microwave radiation may cause injury to male reproduction, which is positively correlated with the radiation dose, and has an obvious late effect.</p>

Effect of quinacrine on inflammatory reaction of blood system induced by microwave irradiation / 中国实验血液学杂志

This work was aimed to investigate the effect of quinacrine on peripheral granulocytes and lymphocytes, interleukin 1 (IL-1) and interleukin 6 (IL-6) in peripheral blood serum of inflammatory reaction induced by microwave irradiation, and observe the protective effect of quinacrine against microwave irradiation injury. BALB/c mice were suffered from microwave irradiation with the total intensity of 50 mW/cm(2) for 30 minutes, at 1 hour before irradiation quinacrine (12.6 mg/kg or 50.4 mg/kg) was orally administrated. Mice received same volume of water for injection instead of quinacrine were named as microwave irradiation group (MR group), and mice received no microwave irradiation but stayed in microwave irradiation environment also for 30 min were set as control. After microwave irradiation, mice were sacrificed and peripheral blood cells were analyzed with cytoanalyzer, and mice serum interleukin-1β, interleukin-6 were detected by radioimmunoassay. The results showed that microwave irradiation increased the count of peripheral granulocytes and lymphocyte along with prolongation of time, while the increase of these cells in mice administrated quinacrine was markedly delayed. The level of IL-1β in serum of mice was significantly increased after 1 day of microwave irradiation (50 mW/cm(2)), and recovered to normal level after 7 days. The 2 concentrations of quinacrine (12.6 mg/kg, 50.4 mg/kg) could suppress level of IL-1β in serum induced by microwave irradiation. The level of IL-6 in serum of mice was gradually increased after microwave irradiation with intensity of 50 mW/cm(2) for 7 days, but quinacrine administration could delay the rise of IL-6 level, specially within time of 2 days. It is concluded that the quinacrine administration can delay the increase of peripheral granulocytes and lymphocytes inducted by microwave irradiation, and may partially suppress the rise of IL-1β and IL-6 in serum. The results of this study suggest that the quinacrine can provide some protective effect against microwave irradiation injury.

Microwave radiation decreases the expressions of occludin and JAM-1 in rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the changes in the expressions of the tight junction related protein occludin and junctional adhesion molecule-1 (JAM-1) of the blood-testis barrier and their significance in rats after microwave radiation.</p><p><b>METHODS</b>Eighty male Wistar rats were exposed to microwave radiation with average power density of 0, 10, 30 and 100 mW/cm2 for five minutes, and dynamic changes in the expressions of testicular occludin and JAM-1 were observed by Western blot and image analysis at 6 h, 1 d, 3 d, 7 d and 14 d after the radiation.</p><p><b>RESULTS</b>There was a significant down-regulation in the expression of the occludin protein at 3 - 7 d, 6 h - 7 d and 6 h - 14 d (P < 0. 05), as well as in that of JAM-1 at 3 - 7 d, 1 - 7 d and 1-14 d (P < 0.05) after exposure to 10, 30 and 100 mW/cm2 microwave radiation.</p><p><b>CONCLUSION</b>The decreased protein expressions of occludin and JAM-1 may play an important role in the microwave radiation induced-damage to the blood-testis barrier.</p>

A aquaporin 4 expression and effects in rat hippocampus after microwave radiation / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the expression of aquaporin 4 (AQP4) after microwave exposure and the correlation with the brain injury by radiation.</p><p><b>METHODS</b>70 male rats were exposed to microwave whose average power density was 0, 10, 30 and 100 mW/cm(2) respectively. Rats were sacrificed at 6 h, 1 d, 3 d and 7 d after exposure. Immunohistochemistry and Western blot were used to detect the expression of AQP4 in protein level in rat hippocampus, and the expression of AQP4 in gene level was measured by in situ hybridization and RT-PCR.</p><p><b>RESULTS</b>The expression of AQP4 in rat hippocampus was abnormal after 10, 30, 100 mW/cm(2) microwave exposure. The protein level showed increased at first and then recovered at 10 and 30 mW/cm(2) groups, while increased progressively in 100 mW/cm(2) group within 14 d (P < 0.01). The gene expression of AQP4 was increased (0.51 +/- 0.02) at the beginning (6 h) and then regained after 10 mW/cm(2) microwave exposure, while in 30 and 100 mW/cm(2) groups, it rose to the peak at 7 d (0.46 +/- 0.02 and 0.43 +/- 0.08) and didn't get back (P = 0.004; P = 0.012).</p><p><b>CONCLUSION</b>Microwave radiation can increase the expression of AQP4 in rat hippocampus. The change might participate in the process of increasing permeability of blood-brain barrier and lead to the brain edema after microwave radiation.</p>

Influence of microwave radiation on synaptic structure and function of hippocampus in Wistar rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effect of microwave radiation on synaptic structure, characteristic of synaptosome, the contents and release of neurotransmitters in hippocampus in Wistar rats.</p><p><b>METHODS</b>Wistar rats were exposed to microwave radiation with average power density of 30 mW/cm(2). Electron telescope was used to study the change of the synaptic structure at 6 h after radiation and to identify synaptosome. Flow cytometry and electron spin resonance were used to study the change of the concentration of Ca(2+) in synapse and the fluidity of membrane proteins of synaptosome. High performance liquid chromatography (HPLC) and spectrophotometer were used to study the changes of contents and release of amino acids and acetylcholine in hippocampus.</p><p><b>RESULTS</b>Microwave radiation of 30 mW/cm(2) caused deposits of synapse vesicle, elongation of active zone, the increase of thickness of postsynaptic density (PSD) and curvature, and perforation of synapse. The concentration of Ca(2+) in synapse (P<0.01) and tc of membrane proteins (P<0.01) of synaptosome increased contents of glutamic acid and glycine (P<0.01) and release of GABA increased the increase of contents and release of acetylcholine, and activity of acetyl cholinesterase (P<0.01) increased.</p><p><b>CONCLUSION</b>Microwave radiation can induce the injure of synaptic structure and function of hippocampus, and then induce the disorder of the ability of learning and memory in rats.</p>

Changes of apoptosis, mitochondrion membrane potential and Ca2+ of hypothalamic neurons induced by high power microwave / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the injury effect and mechanism of hypothalamic neurons after high power microwave (HPM) exposure.</p><p><b>METHODS</b>Primarily cultured hypothalamic neurons were exposed to 10 and 30 mW/cm(2) HPM, and the inverted phase contrast microscope (IPCM) and flow cytometry (FCM) were employed to detect the injury of cells and change of mitochondrion membrane potential (MMP) and Ca(2+) in the cytoplasm of neurons.</p><p><b>RESULTS</b>The ratio of apoptosis was significantly higher than that of the sham exposure (P < 0.05) induced by 10 and 30 mW/cm(2) HPM and necrosis increased significantly (P < 0.05) in the group of 30 mW/cm(2) at 6 h after exposure. The content of Ca(2+) in the cytoplasm of neuron cells increased (P < 0.01) while MMP decreased significantly (P < 0.01) after radiation of 30 mW/cm(2) HPM at 6 h after exposure.</p><p><b>CONCLUSION</b>Apoptosis is one of the major death ways of hypothalamic neurons. The overloading of Ca(2+) and the decline of MMP are involved in the process.</p>

Changes of the expression of beta1-adrenergic receptor and M2-muscarinic acetylcholine receptor in rat hearts after high power microwave radiation / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effect of high power microwave (HPM) radiation on the expression of beta(1)-adrenergic receptor (beta(1)-AR) and M(2)-muscarinic acetylcholine receptor (M(2)-AchR) in cardiomyocytes.</p><p><b>METHODS</b>S-band HPM device of mean power density 2 approximately 90 mW/cm(2) was used to irradiate 150 healthy Wistar male rats. Immunohistochemistry and image analysis were used to study the pathological characteristics of heart tissue and the expression of beta(1)-AR and M(2)-AchR.</p><p><b>RESULTS</b>Radiation of over 10 mW/cm(2) made myocardial fibers disordered in arrangement, degeneration even sarcoplasm condensation, Pace cells necrosis, and Purkinje cells lysis in a dose-dependent manner (r = 0.968, P < 0.05). beta(1)-AR expression in endocardium, membrane and cytoplasm of myocardium of left ventricle was increased on d1 after radiation, peaked on d3 (P < 0.05) and recovered on d14. M(2)-AchR expression was peaked on d1 (P < 0.01) and recovered on d14.</p><p><b>CONCLUSION</b>Certain degree intensity of HPM radiation may cause heart injury, and increased expressions of beta(1)-AR and M(2)-AchR, which may play an important role in the pathophysiology of heart injury induced by HPM.</p>

Studies on the injury effects of hippocampus induced by high power microwave radiation in rat / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the changes of morphology and function in rat hippocampus induced by high power microwave (HPM) radiation.</p><p><b>METHODS</b>Fifty male Wistar rats were radiated by HPM. Then their learning and memory abilities were tested with Y maze and were sacrificed 6 h, 1 d, 3 d and 7 d after radiation. The hippocampus was taken out to study the basic pathologic changes, apoptosis and the expressions of neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP) by means of HE staining, Nissel body staining, in situ terminal end labeling and immunohistochemistry.</p><p><b>RESULTS</b>The learning and memory abilities of rats reduced significantly after HPM radiation. HPM also resulted in rarefaction, edema and hemangiectasia of hippocampus, nervous cells degeneration and necrosis, decrease or disappearance of Nissel bodies. The injuries were more serious in field CA4 and dentate gyrus, which showed dose-effect relationship, and were progressively aggravated within 7 days. The apoptosis cells were significantly increased. NSE was increased in neurons. The NSE positive areas were also seen in the interstitial matrix and blood vessels. GFAP was increased in astrocytes, which became shorter and thicker.</p><p><b>CONCLUSION</b>HPM can damage the abilities of learning and memory and results in morphologic changes in hippocampus. The major pathologic changes are degeneration, apoptosis and necrosis of neurons and edema in interstitium. NSE and GFAP play an important role in the pathologic process.</p>