Alexander Lerchl

Effects of Weak Alternating Magnetic Fields on Nocturnal Melatonin Production and Mammary Carcinogenesis in Rats

Since extremely low frequency (i.e., 50- or 60-Hz) magnetic fields (MFs) from overhead power lines and other electromagnetic sources are ubiquitous in modern societies, the possible carcinogenic effect of such fields recently suggested by epidemiological studies has engendered much concern. However, in view of various unknown and uncontrolled variables which may bias epidemiological studies on MF interactions, a causal relationship between MFs and tumorigenesis can only be determined precisely in animal experiments. The goal of the study reported here was to determine if low frequency MFs at the low flux densities which are relevant for human populations induce tumor-promoting or copromoting effects in a model of breast cancer. Furthermore, since reduction in pineal production of melatonin has been implicated as a cause of tumor promotion by electromagnetic fields, determinations of nocturnal melatonin peak levels in serum were performed during MF exposure. Mammary tumors were induced by intragastric administration of 20 mg (5 mg/week) 7,12-dimethylbenz(a)anthracene (DMBA) in female Sprague-Dawley rats. Groups of 36 rats were either sham-exposed or exposed for 91 days at a 50-Hz gradient MF of 0.3-1 microT, which is a relevant range for elevated domestic MF exposure as arising from neighboring power lines. Nocturnal melatonin levels were significantly reduced by exposure to this weak alternating MF. However, histopathological evaluation of mammary lesions did not disclose any significant difference between MF- and sham-exposed animals. Incidence of mammary tumors was 61% in controls versus 67% in MF-exposed rats. The predominant tumor type was the invasive adenocarcinoma, which was found in 21 rats of both groups. Examination of tumor size did not indicate significant differences in tumor burden between both groups. Furthermore, the incidence of preneoplastic lesions was not altered by MF exposure. Thus, the data of this study indicate that alternating MF do not exert significant tumor promoting or copromoting effects at environmentally relevant flux densities in the rat mammary cancer system.

Melatonin in Epilepsy: First Results of Replacement Therapy and First Clinical Results

At a single evening dose of 5–10 mg, melatonin (MLT), the pineal gland hormone, can exert a positive effect on the frequency of epileptic attacks in children with sleep disturbances of various etiologies. We have shown that the sleep behavior can be normalized and an existing epilepsy can be favorably influenced. Pretherapeutic MLT secretion profiles can provide new information concerning the origin and treatment of these disturbances. In vitro experiments suggest that this effect might be the result of the interaction between MLT and MLT-specific receptors in the neocortex. Due to its favorable safety profile, MLT can be liberally administered in the specified doses and be considered as a useful antiepileptic drug.

Adult Sertoli Cells Are Not Terminally Differentiated in the Djungarian Hamster: Effect of FSH on Proliferation and Junction Protein Organization

Abstract Sertoli cell number is considered to be stable and unmodifiable by hormones after puberty in mammals, although recent data using the seasonal breeding adult Djungarian hamster (Phodopus sungorus) model challenged this assertion by demonstrating a decrease in Sertoli cell number after gonadotropin depletion and a return to control levels following 7 days of FSH replacement. The present study aimed to determine whether adult Sertoli cells are terminally differentiated using known characteristics of cellular differentiation, including proliferation, junction protein localization, and expression of particular maturational markers, in the Djungarian hamster model. Adult long-day (LD) photoperiod (16L:8D) hamsters were exposed to short-day (SD) photoperiod (8L:16D) for 11 wk to suppress gonadotropins and then received exogenous FSH for up to 10 days. Sertoli cell proliferation was assessed by immunofluorescence by the colocalization of GATA4 and proliferating cell nuclear antigen and quantified by stereology. Markers of Sertoli cell maturation (immature, cytokeratin 18 [KRT18]; mature, GATA1) and junction proteins (actin, espin, claudin 11 [CLDN11], and tight junction protein 1 [TJP1, also known as ZO-1]) also were localized using confocal immunofluorescence. In response to FSH treatment, proliferation was upregulated within 2 days compared with SD controls (90% vs. 0.2%, P < 0.001) and declined gradually thereafter. In LD hamsters, junction proteins colocalized at the basal aspect of Sertoli cells, consistent with inter-Sertoli cell junctions, and were disordered within the Sertoli cell cytoplasm in SD animals. Exogenous FSH treatment promptly restored localization of these junction markers to the LD phenotype. Protein markers of maturity remain consistent with those of adult Sertoli cells. It is concluded that adult Sertoli cells are not terminally differentiated in the Djungarian hamster and that FSH plays an important role in governing the differentiation process. It is proposed that Sertoli cells can enter a transitional state, exhibiting features common to both undifferentiated and differentiated Sertoli cells.

Evidence that extremely low frequency Ca2+-cyclotron resonance depresses pineal melatonin synthesis in vitro

The effects of ion cyclotron resonance (ICR)-type magnetic fields on pineal glands were investigated. Both the synthesis and the release of pineal melatonin, the glands major hormone, were significantly (P less than 0.001 in each case) reduced by Ca(2+)-ICR-exposure, presumably caused by a reduced activity (P less than 0.05) of the enzyme N-acetyltransferase. It is concluded that this type of exposure may help to explain some of the effects of electromagnetic fields on biological systems. An extension to the existing ICR theory is presented which explains that ICR-like conditions may occur under various environmental circumstances.

Systematic review of wireless phone use and brain cancer and other head tumors

We conducted a systematic review of scientific studies to evaluate whether the use of wireless phones is linked to an increased incidence of the brain cancer glioma or other tumors of the head (meningioma, acoustic neuroma, and parotid gland), originating in the areas of the head that most absorb radiofrequency (RF) energy from wireless phones. Epidemiology and in vivo studies were evaluated according to an agreed protocol; quality criteria were used to evaluate the studies for narrative synthesis but not for meta-analyses or pooling of results. The epidemiology study results were heterogeneous, with sparse data on long-term use (≥ 10 years). Meta-analyses of the epidemiology studies showed no statistically significant increase in risk (defined as P < 0.05) for adult brain cancer or other head tumors from wireless phone use. Analyses of the in vivo oncogenicity, tumor promotion, and genotoxicity studies also showed no statistically significant relationship between exposure to RF fields and genotoxic damage to brain cells, or the incidence of brain cancers or other tumors of the head. Assessment of the review results using the Hill criteria did not support a causal relationship between wireless phone use and the incidence of adult cancers in the areas of the head that most absorb RF energy from the use of wireless phones. There are insufficient data to make any determinations about longer-term use (≥ 10 years).

No effects of GSM-modulated 900 MHz electromagnetic fields on survival rate and spontaneous development of lymphoma in female AKR/J mice.

BackgroundSeveral reports indicated that non-thermal electromagnetic radiation such as from mobile phones and base stations may promote cancer. Therefore, it was investigated experimentally, whether 900 MHz electromagnetic field exposure influences lymphoma development in a mouse strain that is genetically predisposed to this disease. The AKR/J mice genome carries the AK-virus, which leads within one year to spontaneous development of thymic lymphoblastic lymphoma.Methods320 unrestrained female mice were sham-exposed or exposed (each n = 160 animals) to GSM like 900 MHz electromagnetic fields for 24 hours per day, 7 days per week, at an average whole body specific absorption rate (SAR) value of 0.4 W/kg. Animals were visually checked daily and were weighed and palpated weekly. Starting with an age of 6 months, blood samples were taken monthly from the tail. Animals with signs of disease or with an age of about 46 weeks were sacrificed and a gross necropsy was performed.ResultsElectromagnetic field exposure had a significant effect on body weight gain, with higher values in exposed than in sham-exposed animals. However, survival rate and lymphoma incidence did not differ between exposed and sham-exposed mice.ConclusionThese data do not support the hypothesis that exposure to 900 MHz electromagnetic fields is a significant risk factor for developing lymphoma in a genetically predisposed species, even at a relatively high exposure level.

Effects of Radiofrequency Electromagnetic Fields (UMTS) on Reproduction and Development of Mice: A Multi-generation Study

Abstract Sommer, A. M., Grote, K., Reinhardt, T., Streckert, J., Hansen, V. and Lerchl, A. Effects of Radiofrequency Electromagnetic Fields (UMTS) on Reproduction and Development of Mice: A Multi-generation Study. Radiat. Res. 171, 89–95 (2009). Male and female mice (C57BL) were chronically exposed (life-long, 24 h/day) to mobile phone communication electromagnetic fields at approximately 1966 MHz (UMTS). Their development and fertility were monitored over four generations by investigating histological, physiological, reproductive and behavioral functions. The mean whole-body SARs, calculated for adult animals at the time of mating, were 0 (sham), 0.08, 0.4 and 1.3 W/kg. Power densities were kept constant for each group (0, 1.35, 6.8 and 22 W/m2), resulting in varying SARs due to the different numbers of adults and pups over the course of the experiment. The experiment was done in a blind fashion. The results show no harmful effects of exposure on the fertility and development of the animals. The number and the development of pups were not affected by exposure. Some data, albeit without a clear dose–response relationship, indicate effects of exposure on food consumption that is in accordance with some data published previously. In summary, the results of this study do not indicate harmful effects of long-term exposure of mice to UMTS over several generations.

Reliable analysis of individual human megaton profiles by complex cosinor analysis

Lerchl A, Partsch C‐J. Reliable analysis of individual human melatonin profiles by complex cosinor analysis. J. Pineal Res. 1994: 16: 85–90.

Effects of mobile phone electromagnetic fields at nonthermal SAR values on melatonin and body weight of Djungarian hamsters (Phodopus sungorus)

Abstract:  In three experiments, adult male Djungarian hamsters (Phodopus sungorus) were exposed 24 hr/day for 60 days to radio frequency electromagnetic fields (RF‐EMF) at 383, 900, and 1800 MHz, modulated according to the TETRA (383 MHz) and GSM standards (900 and 1800 MHz), respectively. A radial waveguide system ensured a well defined and uniform exposure at whole‐body averaged specific absorption rates of 80 mW/kg, which is equal to the upper limit of whole‐body exposure of the general population in Germany and other countries. For each experiment, using two identical waveguides, hamsters were exposed (n = 120) and sham‐exposed (n = 120) in a blind fashion. In all experiments, pineal and serum melatonin levels as well as the weights of testes, brain, kidneys, and liver were not affected. At 383 MHz, exposure resulted in a significant transient increase in body weight up to 4%, while at 900 MHz this body weight increase was more pronounced (up to 6%) and not transient. At 1800 MHz, no effect on body weight was seen. The results corroborate earlier findings which have shown no effects of RF‐EMF on melatonin levels in vivo and in vitro. The data are in accordance with the hypothesis that absorbed RF energy may result in metabolic changes which eventually cause body weight increases in exposed animals. The data support the notion that metabolic effects of RF‐EMFs need to be investigated in more detail in future studies.

Lymphoma development in mice chronically exposed to UMTS-modulated radiofrequency electromagnetic fields.

Abstract Sommer, A. M., Bitz, A. K., Streckert, J., Hansen, V. W. and Lerchl, A. Lymphoma Development in Mice Chronically Exposed to UMTS-Modulated Radiofrequency Electromagnetic Fields. Radiat. Res. 168, 72–80 (2007). There are public concerns regarding possible carcinogenic or cancer-promoting effects of electromagnetic fields (EMFs) from mobile phones and base stations. The objective of the present study was to investigate whether chronic exposure to EMFs of the UMTS (Universal Mobile Telecommunication System) influences the development of lymphoma in a lymphoma animal model, the AKR/J mouse. Unrestrained mice were chronically sham-exposed (n = 160) or exposed (n = 160) in identical exposure systems (radial waveguides) to a generic UMTS test signal (24 h per day, 7 days per week, 0.4 W/kg SAR). Additionally, 30 animals were kept as cage controls. Animals were checked visually each day and were weighed and palpated weekly to detect swollen lymph nodes. Starting at the age of 6 months, blood samples were taken from the tail every 2 weeks to perform differential leukocyte counts and to measure the hematocrit. Visibly diseased animals or those older than 43 weeks were killed humanely, and tissue slices were examined for metastatic infiltrations and lymphoma type. The study was performed in a blinded way. Cage control animals had a significantly lower growth rate than those kept in the radial waveguides. The number of ill animals, the mean survival time, and the severity code of the disease did not differ between the experimental groups. Therefore, the data show no negative effects from exposure and corroborate earlier findings in AKR/J mice exposed to GSM EMF (Sommer et al., BMC Cancer 4, 77–90, 2004).