Effect of combination of 1,25-(OH)_2-D_3 and dexamethasone on asthma in rats

AIM: To investigate the therapeutic effect of 1,25-(OH)2-D3 combined with dexamethasone on asthma in rats and its mechanism.METHODS: Forty Wister rats were randomly divided into 4 groups: nomal control group(A),asthma model group(B),group intervened by dexamethasone(C),group intervened by a combination of 1,25-(OH)2-D3 and dexamethasone(D).Group B,C and D were asthma models induced by transperitoneal injection and inhalation of ovalbumin(OVA).Peripheral blood was collected.Both total counts and the percentage of different cell types were calculated.The concentrations of IgE,IL-4 and IL-5 were determined by ELISA.RESULTS: ①After the stimulation of OVA,concentrations of IgE,IL-4 and IL-5 in peripheral blood differed statistically in each group.The concentrations of IgE,IL-4 and IL-5 were(362.84±6.26)×103 IU/L,(22.66±1.59) ng/L,(55.31±2.81) ng/L in B group,and(36.16±2.61)×103 IU/L,(8.37±0.66) ng/L,(13.45±1.07) ng/L in group A,they were statistically different in this two groups(P0.05).They were(188.25±5.55)×103 IU/L,(6.23±0.90) ng/L,(29.64±1.90) ng/L in group C,and statistically different from those in group B(P0.05).Compared with gronp B,the concentrations of IgE,IL-4 and IL-5 were greatly decreased to(182.75±6.00)×103 IU/L,(15.85±1.25) ng/L,(27.85±1.26) ng/L in group D(P0.05)②Compared with gronp A,both total counts and the percentage of EOS were increased in BALF in group B,but compared with group B,the total counts and percentage were decreased in group C and group D(P0.05).CONCLUSION: The combination of dexamethasone and 1,25-(OH)2-D3 may be more effective on the prevention of inflammation in tunica mucosa bronchiorum.The mechanism by which 1,25-(OH)2-D3 acts synergistically with dexamethasone may be that they can reduce the blood levels of IgE,IL-4 and IL-5.