[Effect of pulsed electromagnetic field on the changes of osteoclasts in ovariectomized rats bone marrow culture in vitro].
OBJECTIVE
To investigate the effect of pulsed electromagnetic fields (PEMs) on inducing osteoclastic like cell (OLC) formation changes and apoptosis in ovariectomized (OVX) rats bone marrow culture in vitro.


METHODS
Thirty healthy three-month-old female Wistar rats were either sham-operated (Sham) or ovariectomized (OVX) and randomly divided into three groups: group A (OVX + PEMs, 18 rats), group B (OVX, 6 rats) and group C (Sham, 6 rats); group A was again randomly divided into three groups: A1, A2, A3. The frequencies adopted were 1.5, 2, 75 Hz and 30 minutes for once a day. All rats were fed with normal diet for 3 months, then the bone marrow of all rats were cultured, 2 days later, group A cells (including group A1, A2, A3) were collected and exposed to different frequencies PEMs for 2 weeks (30 min/day). In order to observe the changes of osteoclasts and count their numbers, cells were taken for Wright Giemsa staining, tartrate-resistance acid phosphatase (TRAP) staining and Hoechst 33258 staining.


RESULTS
TRAP staining results indicated the number of OLC in group C was the least, then was group A2, A3, A1, B. The number of OLC in group B was remarkably increased (P < 0.01; vs group C, A2). The number of OLC in group B was significantly increased (P < 0.05; vs group A1, A3). Hoechst 33258 staining results indicated the number of apoptosis of OLC in group C was more than other groups, which of group C, A2 was significantly increased (P < 0.05; vs group B).


CONCLUSIONS
PEMs had decreased the formation of OLC and increased the number of apoptosis of OLC in ovariectomized (OVX) rats bone marrow culture in vitro, the effects of 2 Hz was the best. PEMs would be a new way of osteoporosis therapy.
Bai
Meng-Hai
MH
Institute of Orthopaedics, Lanzhou General Hospital of Lanzhou Military Area, Lanzhou 730050, Gansu, China.
Ge
Bao-Feng
BF
Wei
Zhe
Z
Bai
Jie
J
Cheng
Zi-Feng
ZF
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D001854:Bone Marrow Cells / Q000166:cytology / Q000201:enzymology / Q000528:radiation effects*; D002478:Cells, Cultured; D004574:Electromagnetic Fields; D005260:Female; D007527:Isoenzymes / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology / Q000201:enzymology / Q000528:radiation effects*; D010052:Ovariectomy; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D000071681:Tartrate-Resistant Acid Phosphatase
D007527:Isoenzymes; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase