The Experimental Study Of Ovariectomized Rats For Osteoporosis Based On High-Frequency Low-Magnitude Vibration Of Different Cycles

With the change of the structure of China's population and the advent of the ageing, the prevalence rate of osteoporosis(OP) is increasing. as a bone disease,which is all-prone,difficult to cure and causing great harm to patients. In the past,it is mainly to drug treatment,but the expensive price which has brought heavy economic pressure to family and community. In this paper, I will study a non-drug,non-invasive treatment against osteoporosis based on the stimulation of High-Frequency Low-Magnitude vibration of different cycles to the bone growth environment.According to available literature,as well as our group about the study of loading to animals, which show mechanical stimulation that can promote the growth of bone. There is research also found that vibration can change the bone mechanical structure and the arrangement of trabecular,when to body. which will possible promote the growth of bone and help to resistance osteoporosis. And there are study found that specific scope of vibration can promote bone grow- th.Therefore,this paper has studied the therapy method of High-Frequency Low- Magnitude vibration of different cycles,due to the micro-stress effect on bone growth,and experimental study of ovariectomized rats against a lack of estrogen when movement,Which will cause primary type I osteoporosis. From mechanism of osteoporosis,35 female wistar rats of six–month–old were divided into six groups,each with five (5 prepared to use),and were studied.six groups are basic group (Control,C),ovariectomized(O),ovariectomized and continuous vibration (O+V),ovariectomized and intermittent vibration(O+IV),The average interval time set as a week(O+IV1),two weeks (O+IV2)and four weeks (O+IV4).Then imposing High-Frequency Low-Magnitude vibration( f = 32Hz, a = 0.3g)of different cycles against osteoporosis. In order to observe the growth of bone tissue and structure better, respectively injected tetracycline and calcein as marker,when the experimental animals were killed before the 14th and 13th day,the 4th and 3th day, after eight weeks, All experimental animals were killed and retrieve tibia and ulna,as mechanical experiments and histomorphometry observation.Experiment Methods three-point bending-test measuring the modulus of elasticity,energy absorption and bending stiffness coefficient with Ulna.Grinding a cylinder high 5mm from the proximal tibia as spongy bone specimens,the middle part made a cylinder high 6 mm as compact bone specimens,were destroyed by compression experiment and measured its damage load and modulus of elasticity,Analysising all the experimental data through software origin8.0. the other side of tibia were observed through histomorphometry after drug treatment, Respective -ly use Optical scanning confocal microscope and ordinary optical microscope for bone histomorphometry observation,processing by software Image-Pro Plus 6.0.Result Through experiment result,three-point bending test turn out that O+IV have the modulus of elasticity(E) of ulna improved more than O+V in ovariectomized rats.O+IV1 increased 29.96% significantly (P<0.05)than ovariec- tomized.O+IV2 have also increased 15.79% to ovariectomized , continuous vibration(O+V) increased slightly, only increased 9.62%.In mechaniccal compre -ssion measurement,O+V and O+IV have some improved in the modulus of elasticity(E) of compact bone to ovariectomized.O+IV1 have improved more significantly(P<0.05) than ovariectomized, increased 29.89%.O+IV2 have also improved significantly(P<0.05)than ovariectomized increased 26.22%.O+IV4 have no significant difference(P>0.05) to O+V.the modulus of elasticity (E) of spongy bone of O+IV and O+V have some increased to ovariectomized.O+IV1 have enhanced obviously(P<0.05) than ovariectomized increased 41.4%.O+IV2 have improved significantly (P<0.05) than ovariectomized,increased 36.05%,O+V have increased 7.47% than ovariectomized. histomorphometry also turn out that,in addition to control, O+IV1 have increased in the number of bone,the structure of trabecular bone have become thicker obviously,the bone trabecular have linked more closely and the rate of bone mineralization have increased in some degrees than other groups.results show that, after imposing vibration,the mechanical properties of tibia and ulna increased in some degree,besides control,Especially the spongy bone of O+IV1 more obviously than ovariectomized.Among ovariectomized vibration,O+IV have better difference than O+V on mechanical properties of bone and bone morphogenetics,among intermittent vibration (O+IV) are also different signifycan- tly.Three-point bending and compression results show consistency,the result of observation of decalcified section and mechanical properties tend to be more consistent. Therefore,High-Frequency Low-Magnitude vibration of different cycle against osteoporosis have active role. As reported in previous studies,more on the amplitude and frequency,but little attention have paid to this aspect of time parameter in vibration therapy.Through this study found that vibration have an obvious effiction on physiological process of bone growth.In further research,we can try to study the cycles for one day,two days and three days in experiment. This will be possible alternative drug treatment for osteoporosis,and reduce the side effect of drug deposition in human body,which will made a breakthrough contribution to human health.Conclusion (1)This study through measurement of mechanical properties and histomorphometry observation of rat bone,May be more objective to reflect the physiological conditions of bone which under stress stimulation,which will as a reference for scientific experiments of biomedical engineering for future, provide a theoretical basis and method of the prevention and treatment to osteoporosis for women who have menopaused. (2) From the perspective of mechanical,the stimulation of vibration to ovariectomized rats,which can slow the loss of bone mass,maintain bone mass and sustain the biomechanical properties of bone in a good condition.(3) Introduced in the course of time when vibration therapy to use to the clinical application for osteoporosis, will facilitate to control the time.