Effects of electromagnetic fields on bone loss in hyperthyroidism rat model.

Abstract

Optimal therapeutics for hyperthyroidism-induced osteoporosis are still lacking. As a noninvasive treatment, electromagnetic fields (EMF) have been proven to be effective for treating osteoporosis in non-hyperthyroidism conditions. We herein systematically evaluated the reduced effects of EMF on osteoporosis in a hyperthyroidism rat model. With the use of Helmholtz coils and an EMF stimulator, 15 Hz/1 mT EMF was generated. Forty-eight 5-month-old male Sprague-Dawley rats were randomly divided into four different groups: control, levothyroxine treated (L-T4), EMF exposure + levothyroxine (EMF + L-T4), and EMF exposure without levothyroxine administration (EMF). All rats were treated with L-T4 (100 mg/day) except those in control and EMF groups. After 12 weeks, the results obtained from bone mineral density analyses and bone mechanical measurements showed significant differences between L-T4 and EMF + L-T4 groups. Micro CT and bone histomorphometric analyses indicated that trabecular bone mass and architecture in distal femur and proximal tibia were augmented and restored partially in EMF + L-T4 group. In addition, bone thyroid hormone receptors (THR) expression of hyperthyroidism rats was attenuated in EMF + L-T4 group, compared to control group, which was not observed in L-T4 group. According to these results, we concluded that 15 Hz/1 mT EMF significantly inhibited bone loss and micro architecture deterioration in hyperthyroidism rats, which might occur due to reduced THR expression caused by EMF exposure. Bioelectromagnetics. 38:137-150, 2017. © 2016 Wiley Periodicals, Inc.

• Authors: Chaoxu Liu, Yingchi Zhang, Tao Fu, Yang Liu, Sheng Wei, Yong Yang, Dongming Zhao, Wenchun Zhao, Mingyu Song, Xiangyu Tang, Hua Wu
• Journal: Bioelectromagnetics (Bioelectromagnetics) Vol. 38 Issue 2 Pg. 137-150 (Feb 2017) ISSN: 1521-186X [Electronic] United States
• PMID: 27973686 (Publication Type: Journal Article)
• Copyright: © 2016 Wiley Periodicals, Inc.

Chemical References

• RNA, Messenger
• Receptors, Thyroid Hormone

Topics

• Animals
• Bone Density (radiation effects)
• Disease Models, Animal
• Gene Expression Regulation (radiation effects)
• Hyperthyroidism (blood, complications, urine)
• Magnetic Field Therapy
• Male
• Osteoclasts (pathology, radiation effects)
• Osteoporosis (etiology, metabolism, physiopathology, therapy)
• RNA, Messenger (genetics, metabolism)
• Rats
• Rats, Sprague-Dawley
• Receptors, Thyroid Hormone (genetics)
• Tibia (metabolism, physiopathology, radiation effects)