The effects of prenatal and neonatal exposure to electromagnetic fields on infant rat myocardium

Introduction

Electromagnetic fields (EMF) have adverse effects as a result of widespread use of electromagnetic energy on biological systems. The aim of this study was to investigate the effects of prenatal exposure to EMF on rat myocardium by biochemical and histopathological evaluations.

Material and methods

In this study, 10 pregnant Wistar rats were used. Half of the pregnant rats were exposed to EMF of 3 mT, and the other half to sham conditions during gestation. After parturition, rat pups in the 5 EMF-exposed litters from birth until postnatal day 20 were exposed to EMF of 3 mT for 4 h/day (EMF-exposed group, n = 30). Rat pups in sham litters from birth until postnatal day 20 were exposed to sham conditions (sham group, n= 20).

Results

In the EMF-exposed group, lipid peroxidation levels significantly increased compared to sham. Superoxide dismutase activities decreased significantly in the EMF-exposed group compared to sham. TUNEL staining showed that the number of TUNEL-positive cells increased significantly in EMF-exposed rats compared with sham. Under electron microscopy, there were mitochondrial degeneration, reduction in myofibrils, dilated sarcoplasmic reticulum and perinuclear vacuolization in EMF-exposed rats.

Conclusions

In conclusion, the results show that prenatal exposure to EMF causes oxidative stress, apoptosis and morphological pathology in myocardium of rat pups. The results of our study indicate a probable role of free radicals in the adverse effects of prenatal exposure to EMF. Further studies are needed to demonstrate whether the EMF exposure can induce adverse effects on the myocardium.     

Influence of electromagnetic fields on the electrical activity of rabbit cerebral cortex

Summary The effect of electromagnetic fields on the bioelectric activity of cerebral cortex was investigated on 98 rabbits. As established, the electromagnetic field provokes signal changes in the electroencephalogram: Increased intensity of the magnetic field raises the reaction of the cerebral cortex. Exclusion of various receptor fields (of hearing, vision, smell, vestibular apparatus) had no effect on the reaction of the brain to the action of the electromagnetic field. This led to a suggestion on the possibility of direct action of electromagnetic fields on the brain.Reported at the Conference on Problems of the Electrophysiology of the Central Nervous System, Moscow, 1958.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny Vol. 49, No. 5, pp. 63–67, May, 1960     

低频电磁场与细胞信号系统

１引言在２０世纪,环境中的低频电磁场的强度已经大大增强。环境中的低频电磁场主要起源于电的传送,电的分配及电的使用。近年来的研究表明低频电磁场的生物效应是明显的。ＬｉｂｏｆｆＡ在１９８４年报道了交变电磁场对ＤＮＡ合成的影响［１］。ＳｍｉｔｈＳ．等在１９...     

电磁场在生物医学中的应用

１引言近百年来,人们对随时间作简谐变化的电磁场即连续波电磁场对生物体的各种影响进行了较充分的研究,其在生物医学中的应用也取得了重大进展,形成了一门较为完整的生物电磁学分支,它经历了从热效应到非热效应,从动物活体到细胞及生物大分子,从生物效应到临床应用...     

Ultrastructural mechanisms of serotonin demyelination

The effect of serotonin on the ultrastructure of the white matter in the CNS of dogs was studied. Intracisternal injection of the amine (6 g in 0.1 ml physiological saline) led to considerable disturbances in the myelin and glia in regions of the white matter of the spinal cord adjacent to the cerebrospinal fluid channels. Loss of the regular structure and separation of the lamellae of the myelin with rupture and lysis of the myelin sheath and demyelination were observed. Vacuolar degeneration was observed in the oligodendrocytes; the astrocytes were virtually unchanged. After local intracerebral injection of the amine (2 g in 0.01 ml physiological saline) similar disturbances developed in the white matter of the cerebral hemispheres, but with features of an inflammatory reaction in the late stages of the investigation. In control animals which received injections of physiological saline, changes appeared later and only in the gliocytes. It is concluded that serotonin has the property of injuring myelin and glia.Medical Institute, Rostov-on-Don. (Presented by Academician of the Academy of Medical Sciences of the USSR A. D. Ado.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 5, pp. 606–610, May, 1977.     

Evaluation of the effects of extremely low frequency electromagnetic fields on mammalian follicle development

The aim of this study was to evaluate the effects of pulsed, extremely low-frequency electromagnetic fields (ELF-EMF) on in-vitro mouse pre-antral follicle development. Pre-antral follicles were cultured for 5 days and exposed to ELF-EMF at the frequencies of 33 or 50 Hz. ELF-EMF application did not affect follicular growth over a 3 day culture period, but on day 5 the growth of 33 Hz-exposed follicles was significantly reduced when compared with controls, while the 50 Hz-exposed follicles were not significantly affected. However, ELF-EMF severely impaired antrum formation at both frequencies, as 79 +/- 3% of control follicles developed antral cavities compared with 30 +/- 6% and 51.6 +/- 4% of 33 or 50 Hz-exposed follicles respectively. The follicles with failed antrum formation showed lower oestradiol release and granulosa cell DNA synthesis, but these effects were not related to granulosa cell apoptosis. Furthermore, a high percentage of the in-vitro grown oocytes obtained from exposed follicles had a reduced ability to resume meiotic maturation when compared with controls. These results suggest that ELF-EMF exposure might impair mammalian female reproductive potentiality by reducing the capacity of the follicles to reach a developmental stage that is an essential pre-requisite for reproductive success.     

工频电磁场长期作用影响工作记忆中局部场电位因果网络连接特征

电磁场(EMF)作用对神经系统功能的影响,现已成为电磁生物效应领域广泛关注的问题。本文旨在从神经信息网络连接角度探究工频EMF长期作用对大脑认知功能的影响及其机制。本文将斯普拉格·道利(SD)大鼠随机分为3组,其中模型Ⅰ组将SD大鼠置于2 mT工频EMF中作用24 d;模型Ⅱ组将SD大鼠置于2 mT工频EMF中作用48 d;对照组SD大鼠未经工频EMF作用。随后,采集不同组别SD大鼠执行工作记忆(WM)任务过程中前额皮层(PFC)16通道的局部场电位信号(LFPs),并基于定向传递函数(DTF)构建LFPs因果连接网络,最终通过对比各组SD大鼠在WM过程中LFPs信号因果网络特征参数及行为学表现的异同,探讨工频EMF长期作用对WM的影响。本文研究结果显示,模型Ⅱ组大鼠执行WM任务达到正确率80%以上所需时间及次数明显多于对照组。WM任务中,模型Ⅰ、Ⅱ组因果网络连接强度及全局效率值均明显低于对照组;且模型Ⅱ组中因果网络连接密度值明显低于模型Ⅰ组及对照组。结果表明,经2 mT工频EMF的长期作用,PFC的LFPs信号间因果网络连接强度及全局效率降低,并影响SD大鼠的行为学表现。本文的研究结果从神经网络信息传递的角度揭示了工频EMF作用影响大脑认知功能的可能机制,可为进一步研究其作用机制提供重要的支持。     

Uptake of tryptophan by glial cells and synaptosomes of the rabbit cerebral cortex

The uptake of L-[¹⁴C]tryptophan by glial cells and synaptosomes of the rabbit cerebral cortex was investigated. The assimilation system of the glial cells exhibits high affinity for tryptophan (K_m=0.8 M). Tryptophan uptake by the synaptosomes has lower affinity (K_m=50 M). The psychotropic drugs chlorpromazine and imipramine inhibit glial uptake. The leading role of the glial cells in the nutrition of the neurons and the normal course of neurodynamic processes is confirmed.Laboratory of Neurochemical Pharmacology, Institute of Pharmacology, Academy of Medical Sciences of the USSR, Moscow. Department of Biochemistry, Tbilisi University. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 2, pp. 172–174, February, 1978.     

电磁脉冲辐射致大鼠皮层神经元超微结构损伤效应及对空间学习记忆能力的影响

目的:电磁脉冲辐射(electromagnetic pulse,EMP)可以引起中枢神经系统(CNS)损伤和神经行为学的改变。因此,研究EMP对CNS短期的生物学效应具有重要意义。方法:本文通过电子显微镜技术和Morris水迷宫技术,研究了场强为400 kV/m,脉冲为200次的EMP辐射后短时间内对大鼠皮层神经元超微结构及空间学习记忆能力的影响。结果:辐照射后6 h的大鼠皮层神经元超微结构显示,神经元胞核内异染色质增多;核膜有不同程度凹陷、破损及皱缩。胞质内有明显的线粒体肿胀;胞内粗面内质网呈囊性变、脱颗粒。EMP辐射后24 h时,部分神经元出现染色质浓集、边移,甚至细胞核明显皱缩而失去结构,类似凋亡细胞特点,并有凋亡小体出现。Morris水迷宫结果显示,与正常对照组相比,EMP损伤后,大鼠逃避潜伏期明显延长(P<0.05);动物在平台象限停留时间明显缩短(P<0.01)。结论:400 kV/m的EMP可引起大脑皮层神经元超微结构发生损伤,且导致实验动物空间学习记忆能力的下降。     

The effect of pulsed electromagnetic fields on chondrocyte morphology

Osteoarthritis is a debilitating joint disease where the articular cartilage surface degrades and is unable to repair itself through natural processes. Chondrocytes reside within the cartilage matrix and maintain its structure. We conducted in vitro experiments to investigate the morphological response of cultured human chondrocytes under different pulsed electromagnetic field (PEMF) conditions. In the control experiments, cultured chondrocytes attached to the bottom of a culture dish typically displayed either a stellate or spindle morphology with extended processes. Experimental chondrocyte cultures were placed in a Helmholtz coil to which a ramp waveform was applied. Exposure to PEMFs caused the chondrocytes to retract their processes, becoming spherical in shape. This change in morphology followed a progression from stellate to spindle to spherical. These morphological changes were reflected in an average reduction of 30% in the surface contact area of the chondrocytes to the culture dish. Understanding the mechanisms by which PEMFs affect the morphology of chondrocytes will help lead to new treatments for osteoarthritis.     

胞内钙振荡的同步性对电磁场的响应

电磁场通常通过细胞膜将物理信号转化为生物信号,进而产生生物学效应.本文基于肝细胞钙振荡动力学模型,采用数值分析的方法,研究电磁场对细胞钙振荡同步性的影响,数值结果表明:细胞差异性导致钙振荡的不同,胞间耦合影响钙振荡的同步性;电磁场的频率、强度(调制因子)引起钙振荡的频率和幅值发生变化.     

脉冲电磁场对小鼠成骨细胞归巢基因的作用

目的 研究脉冲电磁场（PEMF）对小鼠成骨细胞上与造血干细胞（HSC）归巢、增殖有关基因的作用.方法 9周龄C57BL/6J小鼠,采用频率70 Hz、电磁场强度2 mT的PEMF作用4～5周,每周作用6d,对照组小鼠不接受PEMF作用.作用结束后,取双侧股骨和胫骨,胶原酶消化、分离细胞,再经磁珠和流式分选、收集ALCAM＋Sca-1-成骨细胞,最后通过表达谱芯片和定量PCR检测ALCAM＋Sca-1-成骨细胞上与HSC归巢、增殖有关的基因.结果 PEMF作用下,成骨细胞上Jagl（其对应HSC上的受体为Notch）和Ang-1（其对应HSC上的受体为Tie-2）的表达增强.结论 PEMF可能通过对ALCAM＋Sca-1-成骨细胞上与HSC归巢和自我更新有关基因的作用,调控HSC.     

脉冲电磁场对破骨细胞和成骨细胞前体细胞作用的研究

目的 研究脉冲电磁场（PEMFs）对破骨细胞和成骨细胞前体细胞的作用。方法单独离体PEMFs作用：取8周龄雌性SD大鼠股骨骨髓细胞,根据PEMFs作用方式分为4个剂量组和对照组．分别进行成纤维细胞集落形成单位（CFU—F）和粒／巨噬细胞集落形成单位（CFU—GM）培养观察。活体结合离体PEMFs作用：取8周龄雌性SD大鼠随机分为3组：2—70组、OVX组和SHAM组,其中2．70组．OVX组进行双侧卵巢切除手术,SHAM组不切除卵巢。术后12周对2—70组大鼠进行PEMFs作用,OVX组和SHAM组不进行PEMFs作用。作用结束后,取大鼠股骨骨髓。根据体外培养过程中是否继续接受PEMFs作用,分为2—70PEMFs作用组／未作用组、OVXPEMFs作用组侏作用组、SHAMPEMFs作用组／未作用组,分别进行CFU．F和CFU．GM培养观察。结果单独离体PEMFs作用时,与对照组相比,4个剂量组的CFU-GM减少,CFU．F增加;活体结合离体PEMFs作用时,剂量组的CFU—F均增加,而CFU—GM各组间均无显著差异。结论单独离体PEMFs作用时,PEMFs对体外培养的破骨细胞前体细胞有抑制作用,对成骨细胞前体细胞增殖有促进作用;活体结合离体PEMFs作用时,PEMFs对成骨细胞前体细胞增殖有促进作用,但未见对破骨细胞前体细胞的抑制作用。     

Detection and properties of benzodiazepine receptors of glial and neuronal fractions of the human cerebral cortex

Bulletin of Experimental Biology and Medicine -     

电磁场对动物免疫系统的影响及其机理

电磁场产生的生物效应已引起极大的关注。本文从其对动物免疫系统的影响及其产生的机理两方面揭示不同条件下,电磁场影响生物机体免疫功能,促进或抑制细胞凋亡,间接地抑制或刺激细胞生长分化、分裂增值的宏观及微观效应,将成为将来提高生物体免疫系统功能的重要手段。     

Action of modulated electromagnetic fields on the emotional component of the systems organization of behavioral acts in rats

This article reviews experimental data providing evidence on the effects of modulated electromagnetic fields of 30–120 V/m with a carrier frequency of 30 MHz modulated sinusoidally at frequencies of 2–50 Hz on the emotional responses accompanying various stages in the systems organization of behavior in rats. The blocking effects of fields were demonstrated in self-stimulation models in different types of conditioned reflex behavior, as well as during extinction of conditioned reflex responses in individual conditions and emotional intercourse. It is suggested that modulated electromagnetic fields which have information effects on the body act on the information component of behavior, i.e., emotion. P. K. Anokhin Science Research Institute of Normal Physiology, Russian Academy of Medical Sciences, 62 B. Nikitskaya Street, Moscow 103009, Russia. Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 83, No. 9, pp. 12–21, September, 1997.     

Sleep EEG alterations: effects of pulsed magnetic fields versus pulse‐modulated radio frequency electromagnetic fields

Studies have repeatedly shown that electroencephalographic power during sleep is enhanced in the spindle frequency range following radio frequency electromagnetic field exposures pulse‐modulated with fundamental frequency components of 2, 8, 14 or 217 Hz and combinations of these. However, signals used in previous studies also had significant harmonic components above 20 Hz. The current study aimed: (i) to determine if modulation components above 20 Hz, in combination with radio frequency, are necessary to alter the electroencephalogram; and (ii) to test the demodulation hypothesis, if the same effects occur after magnetic field exposure with the same pulse sequence used in the pulse‐modulated radio frequency exposure. In a randomized double‐blind crossover design, 25 young healthy men were exposed at weekly intervals to three different conditions for 30 min before sleep. Cognitive tasks were also performed during exposure. The conditions were a 2‐Hz pulse‐modulated radio frequency field, a 2‐Hz pulsed magnetic field, and sham. Radio frequency exposure increased electroencephalogram power in the spindle frequency range. Furthermore, delta and theta activity (non‐rapid eye movement sleep), and alpha and delta activity (rapid eye movement sleep) were affected following both exposure conditions. No effect on sleep architecture and no clear impact of exposure on cognition was observed. These results demonstrate that both pulse‐modulated radio frequency and pulsed magnetic fields affect brain physiology, and the presence of significant frequency components above 20 Hz are not fundamental for these effects to occur. Because responses were not identical for all exposures, the study does not support the hypothesis that effects of radio frequency exposure are based on demodulation of the signal only.     

Experimental study of the effect of an ultrahigh-frequency electromagnetic field on thermal conductivity of living tissues

Department of Pediatric Surgery, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR Yu. F. Isakov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 105, No. 1, pp. 25–27, January, 1988.