Influence of Electromagnetic Fields on Bone Mass and Growth in Developing Rats: A Morphometric, Densitometric, and Histomorphometric Study

Abstract

The effect of electromagnetic fields on bone is debated. In an experimental study of this effect, we compared two lots of growing female rates (both lots n = 15, age 3 weeks, average weight 23.2 +/- 3.3 g), one of which was exposed to a 3-mT, 100-Hz, Helmholtz-type electromagnetic field for 24 hours a day for 30 days, and the other of which served as the control. Bone development and bone mass were evaluated by morphometry, densitometry, and histomorphometry. The rats were killed at 30 days and weighed. The right femurs were dissected, measured, and weighed; bone densitometry was used to determine femoral bone mineral content (BMC) and density (BMD), and histomorphometry of the nondecalcified bone was used to determine trabecular bone volume (Cn-BV-TV%), number (Tb-N mm) and thickness (Tb-Th microm), intertrabecular space (Tb-Sp microm) and growth cartilage thickness (Gc-Th microm). In the rats exposed to the electromagnetic field, BMC and BMD (P = 0.019 and P = 0.002, respectively) and Cn-BV-TV, Tb-N, Tb-Th (P = 0.005, P = 0.036, and P = 0.027, respectively) all were decreased, whereas Tb-Sp was increased (P = 0.002). There were no significant differences in initial and final body weight, or in final femur weight, femur length, and GC-Th. These findings indicate that electromagnetic fields of the type used here reduced bone formation and increased bone resorption without affecting bone development in rats.

Parallel plate model for trabecular bone exhibits volume fraction-dependent bias

“…The plate model is commonly used in studies where changes in trabecular morphology are examined in the presence of changes in volume fraction. This is true for studies of aging, 19,24,25,28 osteoporosis, 17,26 osteoarthritis, 13 the effect of electromagnetic fields, 8 and many others. Because of the convenience and relatively low expense of two-dimensional histomorphometry its use will probably continue in the future.…”

Relative biophysical effects on rat's bone as result of high energy photons and magnetic fields exposures

“…In the present work, 100 male albino rats were used, each of an average weight 170±15 g, and they were divided into subgroups ten rats each group A, E, E 1 , E 2 , E 3 , E 4 ,D 1 ,D 2 ,D 3 , and D 4 . Animals of all groups were housed in normal environmental conditions and the temperature inside the lab varied between (23)(24)(25) ºC. Lighting condition is natural light from large windows during the day and complete darkness during the night.…”

“…[22]. Moreover, the bone collagen concentration was performed by calculating the total amount of hydroxyproline in each sample, assuming 300 hydroxyproline residues per collagen molecule and a molecular weight of collagen of 300,000 D, and was normalized to either tissue dry weight or total protein weight [23]. The measurements of serum ALP were carried out by means of Abbott Architect Plus-C 16000 device with photometry kinetic method [24].…”

Effects of pulsed electromagnetic fields on histomorphometry and osteocalcin in disuse osteoporosis rats

“…To address DOP, the major treatment strategies focus on improving osteoblast activity and reducing bone resorption. Relatedly, many studies reported that PEMF could stimulate the proliferation and differentiation of osteoblasts [13,14]; however, the effect of different magnetic field conditions on cell proliferation and differentiation resulted in radically different results. This experiment, using the conditions in reference [15,16] and homemade equipment, used 3.82 mT, 10 Hz magnetic field conditions.…”