The Influence Of Microwave Radiation On The Morphological Changes Of Rats’ Ileum And The Mechanism Of Action Research

【Objective】1. To study the morphological changes of the epithelial cells from rats’ ileum treatedby microwave radiation.2. To investigate the effect of microwave radiation on the mast cell (MC) andcorticotropin-releasing factor (CRF) expression. To explore the relationship betweenMC and CRF.3. To study the mechanisms of microwave impaired on rats’ ileum.【Methods】SD-rats(♂,20) were randomly divided into two groups: experiment group andcontrol group. The rats of experiment group were given microwave radiation(900MHZ,1.0W,214μm/cm3) within metal trunks (40cm×50cm) at8~10am and2~4pm for consecutive21days, while the control group were conventional breeding.The body weight, surface characteristics and neurobehavioral of SD rats wereobserved during the process of experiment.21days later, the hypothalamus and theterminal ileum were took out from rats which were cardiac perfusion after48h fastingand fixed in4%phosphate-buffered paraformaldehyde. The haematoxylin-eosin (HE)was applied to study the morphological changes of the hypothalamus and the ileummucosa, after which the ultrastructure of the specimens were observed undertransmission electron microscopy. To detect mast cells distribution with toluidine bluestain and CRF localization with immunochemical and then analysis the relationshipbetween the counts of mast cell and the expression level of CRF in each group.【Results】1. The characteristics of yellow body hair, inactive action, drowsiness, moult andlower body weight were observed from the rats of experiment group when comparedwith the control group.2. HE staining of Ilium: In control group, the structure of hypothalamic neuronsformation was normal. In experiment group, the nerve cells decreased and the thirdventricle ependymal got damaged with red blood cells exudation. In control group, thestructure of the small intestine villi was normal, and arranged in neat rows, the smallintestinal gland cell had normal structure as well, the the small intestinal epitheliumwas simple columnar and muscularis could be visible under the loose epthelium cell.Besides, in experiment group, the structure of the intestinal villi was disorder, and the villous structure disappeared as well, the intestinal gland derangement with thespacing widened in midgut gland and myometrial thinning, but muscularis mucosastill can be visible.3. The observation by transmission electron microscrope: In control group,hypothalamic neurons formation were normal, they were integrated with whole nucleiand clear nucleolus, and with integrated mitochondria and golgiosome. In experimentgroup, the ultrastructure of hypothalamic neurons was injured obviously.Mitochondria exhibited vacuole degeneration and crista breaking. Mitochondria andgolgiosome was diffused distribution and the area of them was reduced. In controlgroup, enterocyte were in normal physiological state, they were intact, abundant inorganelle and with integral nucleus. In radiation group, enterocyte were in microbleeding injury. The margin is not distinct with nucleolus disappeared. The structureof these cells, such as mitochondria and goblet cells, were vacuolate. Fatty wereaccumulated in the cytoplasm of small intestinal mucosal epithelial cells.4. In control group and experiment group, the number of mast cells at highmagnification(40×10) is11.133±1.124and18.000±4.850(P<0.05), respectively.5. The light positive action of the level of CRF in control group and strong inexperiment group were observed.【Conclusion】1.The pathological changes in morphology of the epithelial cells of rat ileum wereinduced by microwave.2. The obviously increase of mast cells and CRF in ileum indicated the positivecorrelation.3. The mechanisms of injury on rat ileum by microwave radiation may be referred tothe injuries of hypothalamic neurons, and the dysfunction of hypothalamics-pituitary-gonadal axis system occurred, which causes the increase of CRF, followed by theincreasing of mast cells. The binding of CRF with CRF-R1on membrane of mastcells will activated degranulation of mast cells to release mediators of inflammatoryand cytokines, and result in the damage of morphological structure and screenprotection of mucous membrane from ileum, the mechanisms of which may beregulated by CNS and ENS.