| PrefaceCell growth and divison is affected under simulated weighdess -ness, with a decrease of intercellular contacts and bone deminera -lization, resulting in osteoporosis or bone atrophy, which is not benifi-cal to fracture healing and trauma tissue regeneration. Bone short -distance protein produced by bone is one kind of locally and actively regulatative materials, which plays a vital important role in bone structuring and rebuilding. Such as bone morphogenetic protein ( BMP) ,os-teocalcin ( OC ) and osteopontin ( OPN ) . Further research of bone short - distance protein is helpful to reveal the mechanism of bone metabolism. It has been shown that the activity and formation of some proteins are influenced under weightlessness simulation, which result in functional changes in bone structure, such as the significant decrease of contents of OC in bone and serum. The data home and broad show that the animal model with head down and tail suspended rats is ideal for weighdessness simulation and widely be applied on medicine. So far,most of the studys focus on OC and little of that on BMP. In this study, we study the fracture healing process of rats'lower limbs and their changes and characters of histomorphology and changes of cyto-kines by using histochemical and molecular biology. These findings may elucidate the influence of simulated weightlessness on fracture healing and provide some references for future development of aero-medicine.Materials and Methods64 rats were randomly divided into eight groups: weightlessness group 1 (A) : samples were obtained afer 7 days of head down and tail suspend of newly fractured animals, weightlessness group 2(B) : samples were obtained afer 14 days of head down and tail suspend of newly fractured animals, weightlessness group 3 ( C ) : samples were obtained afer 21 days of head down and tail suspend of newly fractured animals, weightlessness group 4(D) ; samples were obtained afer 28 days of head down and tail suspend of newly fractured animals. Control group 1 ( E) ; samples were obtained afer 7 days of newly fractured animals. Control group 2(F) ; samples were obtained afer 14 days of newly fractured animals. Control group 3(G) ;samples were obtained afer 21 days of newly fractured animals. Control group 4( H) -.samples were obtained afer 28 days of newly fractured animals. All groups were matched for age,weight, gender and nutritional state.First, we set up the fractured models of rats; anaesthesia method adopt ketamine and 846 liquids. The injection approach is intra - abdominal injection. The operation method is selecting the unilateral lower back limbs, And snipping the unilateral middle part of fibula using ophthalmological scissors and stitching the wound. Second, the models of fractured rats in weightlessness are built; Under the condition of anaesthesia, tails of rats are fixed on the top of rats'cage by adhesive plaster of zinc oxide. Upper limbs can move and touch the bottom of cage. Keep enough distance between rats themselves and rats and the walls of cage in order to avoid influence on the building of the modelsof head down and tail suspended of rats. Routine feed and check and clean. Finally,kill the rats by breaking off the cervix. Fibula samples are acquired and fixed according the demands of pathological department. BMP is measured by two steps of immunohistochemistry. And samples are observed by transmission electron microscope.Results一,Standard of measurement of immunohistochemistry: Randomly select 10 visual fields of HP,The average number of positive cells below 10 is named negative; The average number of positive cells above 50 is named strong positive; While the average number of positive cells between 10 and 50 is named positive.1. There was no significant difference between A group and E group, X2 =1.640 (P>0.05).2. There was significant difference between B group and F group, X2=3.000 (0.05 |
PDF Full Text Request