Effect Of Vitamin D2on The Expression Of IL-4and ICAM-1in Lung Tissue Of Asthmatic Rats

Objective:Asthma is a variety of cells, especially mast cells, eosinophils, T lymphocytes,neutrophils, airway epithelial cells and a variety of cellular components involved in thechronic airway inflammation and disease, immune regulation plays an important role inasthma pathogenesis, scholars more and more attention to the role of vitamin D inimmune regulation, the study found that vitamin D on the Th1/Th2balance have amoderating role, in this experimental rat model of asthma intervention by vitamin D2,the level of IL-4in bronchoalveolar lavage fluid, cell count and classification inbronchoalveolar lavage fluid,lung tissue expression of ICAM-1were compared.Exploreanti-inflammatory effects of vitamin D in asthma rats, suggesting its possiblemechanism.Methods:In accordance with the principles of randomization,30male SD rats were randomlydivided into three groups, asthma group, vitamin D2group and control group (n=10)，(1) Asthmatic group: Rats were immunized on day1, day8and day15by intraperitoneal injection of100mg ovalbumin (OVA) in1ml of saline with100mg ofaluminum hydroxide. From day16the animals were challenged with aerosolized OVA(1%in saline) for30minutes per day for7consecutive days.(2) vitamin D2Group:From the first15days OVA sensitized rats given intraperitoneal injection of vitamin D2 5×10~5U/(kg.d) every2days,total of3times.(3) Control group: OVA andvitamin D2was replaced with normal saline (NS). In the24hours after the last challenge, rats were killed to collect lung tissue and airway lavage fluid (BALF). BALFcells and supernatant is separated by centrifugal separation. lung tissue is made intolung biopsy specimens through dehydration, paraffin embedding.Interleukin4(IL-4)levels in BALF supernatants were measured by elisa method, and improved cattle’scount Taiwan on BALF precipitation cell count and cell smear afterprecipitation count.Total and differentiated leukocytes counts in bronchoalveolar lavage fluid (BALF),.Intercellular adhesion molecule1levels of lung specimens were assessed with the useof immunohistochemical. Eachgroup of indicators data were analyzed and compared bystatistical methodsResults:The level of IL-4in VD2group（501.54±17.96）pg/ml was significantly lower than theasthma group（615.37±94.77）pg/ml (P <0.01); the VD2group of IL-4content comparewith the control group have no significant difference.The total number of cells（72.80±24.44）×10~6, neutrophil coun（t18.20±8.14）×10~6, eosinophil coun（t3.80±1.75）×10~6in bronchoalveolar lavage fluid sediment of the VD2group was significantly lowerthan the asthma group (P <0.01); the total number of cells（47.20±18.23）×10~6,neutrophil count （7.40±1.96）×10~6, the eosinophil count （0.80±0.79）×10~6inbronchoalveolar lavage fluid sediment of the control group was lower than the VD2group (P<0.01); the VD2group of lung tissue ICAM-1expression (0.23±0.03)compared with the asthma group (0.34±0.10) was significantly lower (P <0.01); theVD2group lung tissue ICAM-1expression (0.23±0.03)was high compare with controlgroup (0.17±0.38)(P <0.01).Conclusion:Vitamin D2can inhibit the Th2cytokines IL-4levels, inhibition of ICAM-1levels inasthmatic rats, reduce lung airway inflammatory cell infiltration, reducing the response of airway inflammation in asthma.