ABSTRACT
In previous studies it has been shown that exposure of mice to a 12-Hz 6 mT unipolar square pulsed magnetic field (PMF) suppressed the excess of weight due to application of 1st cold-pressure sunflower oil. This time we considered the effect of oil and/or PMF on the growing curves lifespans of mice. The exposure took place for 30 min 5 days a week, from the 7th week of life to death. The results are 1) a broken slope in the growing curves from the 125th day of aging: the exposed mice were lighter than the controls, keeping the differences between the growing curves needed a repeated exposure all life long; 2) a significant increase in the lifespan of the controls which received oil versus the controls which received water; 3) an increase in the lifespan of the exposed mice versus the non-exposed control batches. On one hand it has been reported that essential polyunsaturated fatty acids found in first cold-pressure sunflower oil played a prominent role in membrane structures and in immune equilibrium. On the other hand, it was shown that oscillating electric fields could activate Na+K+-ATPase.
Subject(s)
Life Expectancy , Magnetics , Plant Oils/pharmacology , Animals , Female , Mice , Organ Size/drug effects , Organ Size/radiation effects , Pressure , Sunflower OilABSTRACT
BACKGROUND: Liver is a crucial organ in metabolism. For instance liver is the main source of circulating lipoproteins. METHODS: In this paper cholesterol and triglyceride plasma levels were measured in male rats previously exposed to pulsed magnetic fields (PMF) used in therapy. Rats underwent a one-hour exposure to a 6 mT 12 Hz PMF. RESULTS: Twenty-four hours after the end of the exposure to the PMF the rats' livers were heavier, cholesterol and triglyceride plasma levels decreased. All these variations were significantly different according to a variance ratio test as was a rebound in triglyceride level 48 hours after the end of the exposure. Normal values were observed 48 and 96 hours after the end of exposure respectively for cholesterol and triglycerides. CONCLUSIONS: These alterations may be due to a reversible accumulation of either triglycerides or of their precursors in liver following acute exposure to a 12 Hz PMF.
Subject(s)
Cholesterol/blood , Liver/metabolism , Magnetics , Triglycerides/blood , Animals , Liver/anatomy & histology , Male , Organ Size/physiology , Rats , Rats, WistarABSTRACT
Liver cell necrosis was induced in rats by a galactosamine injection. Cell death was due to an increase of Ca++ intracellular levels and was also under the control of genes. Rats were then either exposed or not to a 6 mT 100 HZ pulsed magnetic field (PMF) and they either received or not methylsilane-triol injections. Animals were sacrificed twenty-seven hours after a galactosamine injection. On the one hand it appeared from transaminase levels that the PMF increased the number of animals which were sensitized to galactosamine but decreased transaminase levels. On the other hand PMF decreased the protective effect of MST against galactosamine. We may suggest that PMF should be considered as an additional cellular signal received through genes which would determine the evolution towards or against apoptosis according to the age of the cell itself but also the Ca++ intracellular level.
Subject(s)
Chemical and Drug Induced Liver Injury/therapy , Galactosamine/toxicity , Magnetics , Organosilicon Compounds/pharmacology , Salicylates/pharmacology , Animals , Male , Rats , Rats, WistarABSTRACT
In a previous work a decrease in cholesterol and triglyceride plasma levels was observed in rats 24 hours after their exposure to a 12 Hz 6 mT pulsed magnetic field (PMF). This time, a study of intensity effects of a 12 Hz PMF for a sixty-minute exposure and of length of exposure for a 12 Hz 6 mT PMF took place. Non-linear effect-dose relationships were observed for the PMF intensity as well as for the length of exposure used. The highest decreases in cholesterol and triglyceride levels were obtained after to a sixty-minute exposure with 1.5 mT and 12 mT.
Subject(s)
Cholesterol/blood , Magnetics , Triglycerides/blood , Animals , Body Weight , Dose-Response Relationship, Radiation , Male , Rats , Rats, Wistar , Time FactorsABSTRACT
This work was undertaken to check the effects of 460 Hz pulsed magnetic fields (PMF) on the growth curves of mice, and to observe any possible long term effect. Effects on the growth curves have already been shown in young female AKR mice. Eight-week-old Swiss female mice underwent, until death, a twice weekly a one-hour-exposure to a 460 Hz 6 mT PMF. They initially showed slower than that of the controls, but it later became faster, 460 Hz 9 mT PMF always kept the growth curves of the exposed mice under those of the controls. However, no difference with controls was noticed when the mice were exposed after the thirtieth week. Moreover, there was no difference in the survival or in pathological aspects between the exposed mice and controls.
Subject(s)
Aging/physiology , Body Weight/physiology , Electromagnetic Fields , Animals , Female , Mice , Mice, Inbred StrainsABSTRACT
Pulsed magnetic fields (PMF) have already proved to have a certain influence not only on leucocytes in vitro but also on thymocytes in vivo. C3H/Bi tumoral female mice were either exposed to 12 Hz or 460 Hz, and to 6, 9 or 20 mT PMF just two weeks after the tumors had appeared and this until the moment they died. Actually, all the survival times as well as the average weights of spleens lungs, and tumors were then taken into account at the very death of the mice. In a general way there happened to be no difference in spite of the different frequencies used and the rates of lungs with metastases were not at all influenced by the exposure itself. However a 3-hour-exposure once a week could increase the mean survival times whereas a 15-minute-exposure to a 6 mT PMF twice a week gave lighter spleens than those of the controls and an exposure either to 9 mT or to 20 mT gave heavier tumors in general.
Subject(s)
Electromagnetic Fields , Mammary Neoplasms, Animal/pathology , Animals , Female , Mammary Neoplasms, Animal/mortality , Mice , Mice, Inbred C3H , Organ Size , Survival RateABSTRACT
For thirty minutes Swiss mice were exposed to a 60 G 12 Hz or a 460 Hz pulsed magnetic field. The blood-brain flow was then calculated thanks to an i.v. injection of 99mTc HM-PAO, 0, 3 or 24 hours after the end of the exposure. In the end, it was in fact impossible to discriminate between the exposed mice and the controls.
Subject(s)
Cerebrovascular Circulation , Magnetics , Animals , Female , MiceABSTRACT
AKR mice were exposed to a 6 mT, 12 Hz or 460 Hz pulsed magnetic field for 30 minutes twice a week. The exposure took place in utero and/or during the life span for five consecutive generations. For the exposure the grown-up mice were put into a container which caused a restraint stress. That stress brought about lighter newborn mice and also a higher number of newborn mice which were to die. The exposure lessened the loss of weight due to the stress. It had no noticeable effect on the average numbers of newborn mice per litter, of dead newborn mice and on the sex-ratio.
Subject(s)
Animals, Newborn/physiology , Magnetics , Animals , Birth Weight , Female , Male , Mice , Mice, Inbred AKR , Sex FactorsABSTRACT
AKR mice were exposed to a 6 mT, 12 Hz or 460 Hz pulsed magnetic field (PMF) 30 minutes twice a week. The exposure took place in utero and/or during the life span for four consecutive generations. The adult mice exposed to the 460 Hz PMF only after the birth time were lighter than the controls; for the two frequencies the decrease in weight with the ageing was less pronounced than in the controls. When the exposure took place in utero the exposed new-born mice were heavier than the controls. The difference in weight progressively disappeared when the mice were exposed to the 12 Hz PMF, persisted when the mice were exposed to the 460 Hz PMF.
Subject(s)
Body Weight/radiation effects , Magnetics , Mice, Inbred AKR/growth & development , Animals , Birth Weight/radiation effects , Embryonic and Fetal Development/drug effects , Female , Male , Mice , Mice, Inbred AKR/embryology , Pregnancy , Prenatal Exposure Delayed EffectsABSTRACT
In a previous experiment, the exposure of tumoral C3H/Bi female mice to a 9 mT, 460 Hz pulsed magnetic field led to an increase in the length of survival in the late period of the disease; this might be due to a hampered metastatic process. In the present study 27 controls and 52 exposed mice were treated with the same protocol (a 10-minute exposure, 3 non-consecutive days a week, from 2-3 weeks after the tumors appeared until death) but with a 12 Hz PMF. In this experiment the 12 Hz PMF appeared to increase length of survival times in the early period of the disease.
Subject(s)
Electromagnetic Fields , Mammary Neoplasms, Experimental/radiotherapy , Animals , Electromagnetic Fields/adverse effects , Female , Lung/pathology , Mammary Neoplasms, Experimental/mortality , Mammary Neoplasms, Experimental/pathology , Mice , Mice, Inbred C3H , Organ Size , Spleen/pathologyABSTRACT
Leukemia-prone AKR mice were exposed twice a week to a 6 mT, 12 Hz or 460 Hz pulsed magnetic field for 30 min. If we take into account the five consecutive generations of mice, the above exposure actually took place in utero and, or during their life span. There was no difference in the incidence of leukemia or in the actuarial survival curves or in the average spleen or thymus weights.
Subject(s)
Electromagnetic Fields/adverse effects , Leukemia/mortality , Actuarial Analysis , Animals , Disease Susceptibility , Female , Incidence , Leukemia/epidemiology , Leukemia/pathology , Male , Mice , Mice, Inbred AKR , Organ Size , Spleen/pathology , Survival Rate , Thymus Gland/pathologyABSTRACT
An exposure of adult mice to a pulsed magnetic field (PMF) increases thymus weight. In this work, thymic lymphocytes were studied by cellular electrophoresis because the proliferation and maturation of these cells is linked to an increase in their electrophoretic mobility (EM). Fifteen-week-old female Swiss mice were exposed for 30 min to a 6 mT PMF, 12 or 460 Hz in frequency, according to different modalities. The EM of the thymic cells, suspended in saline were measured from 0 to 96 h after the end of the exposure. For some of the mice the whole body, for others the head only or the body without the head was exposed; the animals were awaken or narcotized, prepared or not with 6-hydroxydopamine. The modifications of the EM are in favour of an action of the PMF on the thymus through the central nervous system.
Subject(s)
Magnetics , Peripheral Nerves/physiology , Thymus Gland/radiation effects , Animals , Cell Separation/methods , Electrophoresis/methods , Female , Mice , Oxidopamine , Reference Values , Thymus Gland/cytology , Time Factors , WakefulnessABSTRACT
The hypothesis that magnetic fields act only on deficient functions has been tested through the weight of the thymus in mice. The involution of the thymus in mice is known to begin early in life. It is marked by a decrease in weight. Female Swiss mice of different ages were exposed to a pulsed magnetic field 0.6 or 6 mT in intensity, 12 or 460 Hz in frequency. It was shown that the weight of the thymus in 8-week-old mice was not modified by the exposure, while the weight of the thymus in 15-week-old mice was increased. The maximum increase, about 16% relative to the controls, was obtained 24 hours after a 30 minutes' exposure. Hydrocortisone or cyclophosphamide prevented the effect. The increase in weight has been considered to be due to an increase of the number of the cells in the thymus.
Subject(s)
Magnetics , Thymus Gland/anatomy & histology , Animals , Cyclophosphamide/pharmacology , Female , Hydrocortisone/pharmacology , Mice , Organ Size/drug effects , Reference Values , Thymus Gland/drug effectsABSTRACT
In a previous experiment an increase in the survival time of leukaemia-prone AKR mice was observed by exposure to a 600 mT or 800 mT static magnetic field when the mice were at least 200 days old. In this experiment 200-day-old-mice were exposed to a 6 mT pulsed magnetic field (PMF) for 30 minutes a day, twice a week until death. The frequency of the field was 12 Hz or 460 Hz. The exposed mice died from leukaemia but had an increased survival time; the average increase was 14.25% compared to the controls. Both the frequencies gave similar results.
Subject(s)
Longevity , Magnetics , Mice, Inbred ICR/physiology , Animals , Disease Susceptibility , Female , Leukemia, Experimental/genetics , Leukocyte Count , Mice , Reference ValuesABSTRACT
Female C3H/Bi mice develop spontaneous viral mammary carcinoma which can metastasize to the lungs. Two hundred and forty tumoral mice were either exposed to a toroïdal pulsed magnetic field, 12 Hz, 100 Hz or 460 Hz in frequency or used as controls. The exposure was mainly done 10 min. a day, 3 days a week, or 30 minutes once a week from about 2 to 3 weeks after the appearance of the tumors until death. In comparison with the controls, the exposed mice showed lighter spleens and lungs; this last observation could mean fewer pulmonary metastases. The weight of the tumors has been found lighter for 460 Hz MF, not changed for 100 Hz MF, heavier for 12 Hz MF, but lifespans were not altered by the exposure.
Subject(s)
Magnetics , Mammary Neoplasms, Experimental/pathology , Animals , Female , Leukocyte Count , Lung/anatomy & histology , Lung/pathology , Mice , Mice, Inbred C3H , Organ Size , Reference Values , Spleen/anatomy & histology , Spleen/pathologyABSTRACT
Young male rats were exposed to constant uniform magnetic fields of 400 and 800 millitesia (mT). No changes were observed in the body and in the pancreas weight, in the pancreatic insulin content and in the in vitro insulin release of Langerhans islets, in glucose and insulin plasma levels. The magnetic fields abolished the insulin effect on glucose uptake of diaphragms, but not on 1-14C-glucose oxidation. In adipocytes 400 mT increased insulin-stimulated 1-14C-glucose oxidation, when expressed as percentage of mean basal oxidation, and 800 mT diminished it.
Subject(s)
Electromagnetic Fields , Electromagnetic Phenomena , Insulin/metabolism , Islets of Langerhans/radiation effects , Adipose Tissue/metabolism , Animals , Blood Glucose/metabolism , Male , Muscles/metabolism , Rats , Rats, Inbred StrainsABSTRACT
45Ca2+ efflux from neonatal isolated chick brains was measured. The brains were exposed to uniform or nonuniform static magnetic fields. The field intensity ranged from 200-900 mT. The exposure took place during incubation and/or when efflux was being measured. No difference appeared in the 45Ca2+ efflux between controls and exposed brains.
Subject(s)
Brain/metabolism , Calcium/metabolism , Electromagnetic Fields , Electromagnetic Phenomena , Animals , Calcium Radioisotopes , Chickens , In Vitro TechniquesABSTRACT
The influence of a life-long exposure to static magnetic fields (SMF) on the lifespan of female AKR mice which develop spontaneous lymphoblastic leukaemia was investigated. Exposure all day long to a circular SMF, 4.6 mT maximal intensity or 2 h a day, 5 consecutive days a week to a uniform SMF of 400 mT did not modify the lifespan of mice. Exposure 2 h a day, 5 consecutive days a week to a uniform SMF of 600 or 800 mT modified the lifespan: about 50% of the population had a longer survival than the controls. Mice exposed 30 min a day 5 consecutive days a week to a non-uniform SMF presented the same trend.
