Thyroid morphology and activity does not respond to ELF electromagnetic field exposures

Lafreniere, Ghislaine F.; Persinger, Michael A.

doi:10.1007/bf01922772

Cited by 13 publications

(8 citation statements)

References 7 publications

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“…However, our data do not agree with data obtained by Lafreniere and Persinger (1979) or Selmaoui et al (1997). Lafreniere and Persinger (1979) had shown that no alterations in serum T 3 and T 4 concentrations were found in rats exposed to 0.5 Hz EMF perinatally or/and as adults. The study of The thyroidian functions may be affected by many factors during different phases of the individual's lifetime and in function of age, nutrition, gender, and pregnancy.…”

Section: Discussioncontrasting

confidence: 99%

“…They found that serum T 3 and T 4 concentrations were significantly lower in all exposed animals, except in Group I. However, our data do not agree with data obtained by Lafreniere and Persinger (1979) or Selmaoui et al (1997). Lafreniere and Persinger (1979) had shown that no alterations in serum T 3 and T 4 concentrations were found in rats exposed to 0.5 Hz EMF perinatally or/and as adults.…”

Section: Discussioncontrasting

confidence: 99%

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Effects of the Electromagnetic field, 60 Hz, 3 µT, on the hormonal and metabolic regulation of undernourished pregnant rats

2009

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Epidemiological studies have implicated maternal protein-calorie deficiency as an important public health problem in developing countries. Over the last decades, a remarkable diffusion of electricity and an increased level of the electromagnetic field (EMF) in the environment have characterized modern societies. Therefore, researchers are concerned with the biological effects of 50-60 Hz, EMF. The aim of this paper is to show the effects of EMF of 60 Hz, 3 µT, exposure for two hours per day in the regulation of the hormonal and metabolic concentrations in pregnant rats, which were fed by Regional Basic Diet (RBD) during their pregnancy as compared with pregnant rats fed a standard diet. Pregnant rats exposed to EMF of 60 Hz, 3 µT, over the pregnancy and fed with RBD presented an increase in glucose release when compared with the Group subjected only to the RBD ration. Rats fed RBD presented a decrease in their insulin and cortisol serum levels when compared with the Group fed with casein. The T 3 and T 4 concentrations presented the greatest variation among the Groups. The relation T 4 :T 3 was much exaggerated in the Group subjected to RDB and exposed to EMF when compared to the others. In conclusion, the group subjected to the association of EMF and undernutrition suffered a decrease in its serum concentration of T 4 and T 3 when compared to the well-nourished group and the relationship T 4 :T 3 in the former group was almost eighteen-fold the later one.Keywords: casein, electromagnetic field, metabolism, hormone, regional basic diet, undernourished pregnant rats. Efeitos do campo eletromagnético, 60 Hz, 3µT, na regulação hormonal e metabólica de ratas prenhes desnutridas ResumoEstudos epidemiológicos têm mostrado que a deficiência proteico-calórica é um importante problema nos países em desenvolvimento. Durante as últimas décadas, a sociedade moderna tem sido caracterizada pelo aumento no número de equipamentos elétricos e como consequência um aumento no nível do campo eletromagnético (CEM) no ambiente. No entanto, os pesquisadores estão preocupados com os efeitos biológicos dos CEM de 50-60 Hz. O objetivo deste artigo é mostrar os efeitos do CEM de 60 Hz, 3 µT, nas concentrações hormonais e metabólicas de ratas prenhes, expostas duas horas por dia ao CEM, alimentadas pela Dieta Básica Regional (DBR) comparando com ratas submetidas às mesmas condições, mas alimentas com dieta padrão. Ratas prenhes expostas ao CEM de 60 Hz, 3 µT, durante a prenhez e alimentadas com a DBR apresentaram um aumento na liberação de glicose quando comparadas com o grupo alimentado pela DBR sem CEM. As ratas alimentadas pela DBR apresentaram uma diminuição nos níveis de insulina e cortisol quando comparadas com o grupo alimentado pela caseína. As concentrações de T 3 e T 4 apresentaram a maior variação entre os grupos. A relação T 4 :T 3 foi muito exagerada no grupo alimentado pela DBR e exposto ao CEM quando comparado com os outros. Conclusão, os animais que foram submetidos à desnutrição e ao CEM sofreram uma diminuição na ...

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Section: Discussioncontrasting

confidence: 99%

Section: Discussioncontrasting

confidence: 99%

Effects of the Electromagnetic field, 60 Hz, 3 µT, on the hormonal and metabolic regulation of undernourished pregnant rats

2009

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“…Intermittent and continuous exposure of men to 50 Hz 10 mT MFs for 24 did not cause any variation in T4 but demonstrated a circadian T4 secretion pattern that decreased during the dark period and was maximum during the day [Selmaoui et al, 1997]. Similar findings in T4 and no changes in thyroid morphology were reported earlier in rats exposed to 0.5 Hz EMF [Lafreniere and Persinger, 1979]. Humans exposed to 2.9 mT, 40 Hz and 25-80 mT, 400 Hz MF had increased and decreased T4 concentrations in blood, respectively [Woldanska-Okonska and Czernicki, 2003].…”

Section: Discussionsupporting

confidence: 86%

Plasma concentrations of thyroxine in dairy cows exposed to 60 Hz electric and magnetic fields

Burchard

Nguyen

Rodríguez

2006

Bioelectromagnetics

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Two experiments were carried out to assess the effects of electric and magnetic fields (EMF) on blood thyroxine (T4) in dairy cattle. In experiment 1, 16 lactating pregnant Holstein cows were exposed to 10 kV/m, 30 microTesla (microT) EMF. The animals were divided into two groups of eight animals each. Each group was exposed to EMF according to one of two treatment sequences of three periods of 28 days each. Sequence 1 was EMF OFF-ON-OFF and sequence 2 was EMF ON-OFF-ON. During the last day of each treatment period, blood samples were collected every 4 h for 24 h to estimate T4 plasma concentrations. In experiment 2, 16 nonlactating, nonpregnant, multiparous Holsteins were exposed to 10 kV/m, 30 microT EMF. The animals were divided into two groups of eight animals each. Each group was exposed to EMF according to one of the two treatment sequences described above, except that each period amounted to the number of days corresponding to one estrous cycle. During treatment, blood samples were collected every other day for T4 analysis. In both experiments, the light cycle emulated a short photoperiod (8 h light/16 h dark). During the ON periods, the animals were exposed to EMF for 16 h, 8 h of the light period plus the first 8 h of during the dark period. In experiment 1, exposed animals did not have any change in T4 plasma concentrations due to treatment (P = .0968), but, the time of sample collection revealed a significant difference (P = .0012). In experiment 2, the effect of period (P = .0009) and the treatment by days interaction (P = .0003) were statistically significant. We conclude that a worst case scenario exposure of dairy cattle to 10 kV/m, 30 microT EMF influences, in a moderate fashion, the blood levels of thyroxine.

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“…In rats exposed to EMF (0.5·Hz; 10 -6 , 10 -7 and 10 -8 ·T) perinatally, or as adults aged 180-200·days at the beginning of the experiment, no alterations were seen in thyroid follicle morphology or thyroid hormone concentrations (Lafreniere and Persinger, 1979). An increased level of circulating TSH and T4 was found in rats exposed to 50·Hz EMF of 20·mT for 18·h, but a decreased concentration of circulating thyroid hormones after a single exposure to EMF (Udintsev et al, 1978).…”

Section: Table·1 the Number Of Observations Median Values With The mentioning

confidence: 96%

Light and electron microscopic study of the thyroid gland in rats exposed to power-frequency electromagnetic fields

Rajkovic

Matavulj

Johansson

2006

Journal of Experimental Biology

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SUMMARY The effect of 50 Hz electromagnetic field (EMF) on thyroid gland was studied using light and transmission electron microscopes. Two-month-old male rats were exposed to an EMF (100-300 μT, 54-160 V m-1) for 4 h a day, 5 days a week for 1 month. A predominance of microfollicles with less colloid content and dilated blood capillaries was found in the EMF group. Stereological counting showed a statistically significant increase of the volume density of follicular epithelium, interfollicular tissue and blood capillaries as well as the thyroid activation index, as compared to the controls. The volume density of colloid significantly decreased. Ultrastructural analysis of thyroid follicular cells in the EMF group revealed the frequent finding of several colloid droplets within the same thyrocyte with the occasional presence of large-diameter droplets. Alterations in lysosomes, granular endoplasmic reticulum and cell nuclei compared to the control group were also observed. Taken together, the results of this study show the stimulative effect of power-frequency EMF on thyroid gland at both the light microscope and the ultrastructural level.

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Thyroid morphology and activity does not respond to ELF electromagnetic field exposures

Cited by 13 publications

References 7 publications

Effects of the Electromagnetic field, 60 Hz, 3 µT, on the hormonal and metabolic regulation of undernourished pregnant rats

Effects of the Electromagnetic field, 60 Hz, 3 µT, on the hormonal and metabolic regulation of undernourished pregnant rats

Plasma concentrations of thyroxine in dairy cows exposed to 60 Hz electric and magnetic fields

Light and electron microscopic study of the thyroid gland in rats exposed to power-frequency electromagnetic fields

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