The Study Of CAMP/cGMP In Children With Asthma And Regulatory Action Of Meglumine Adenosine Cyclophosphate

Objective.Asthma is viewed as a chronic inflammatory disease of the airway, which is common in childhood.Many inflammatory cells,such as eosinophil,mast cell,T lymphocyte,neutrophil and their ingredients are involved in it.These cells interact activate and secret various cytokines,thus cause the injury of mucosal epithelium and high bronchial reaction.Nowadays,studies are still undergoing on mechanism,evulation and therapeutic effect of asthma and more attention are paid to the imbalance of cAMP/cGMP system.As is known that to keep the stable strain state depends on the functional receptors of the cellular membrane and two intracellular second messages named cAMP and cGMP.cAMP serves as bronchial expander, while cGMP goes the contrary,with releasing granules of mast cell and inflammatory mediators.So spasm of bronchial smooth muscle and asthma can be induced by the decrease of cAMP or/and elevated level of cGMP.The ratio of cAMP/cGMP is perhaps a desired biochemical target for monitoring and directing administration to children with asthma and evulating therapeutic effects of medication.Meglumine adenosine cyclophosphate is a new derivant from cAMP.It translocates into the cell by enhancing fat-soluble infiltration of cAMP,and up-regulates the concentration of intracellular cAMP.cAMP helps to stabilize cellular membrane,inhibit the excretion of inflammatory mediators,reduces the edema and hemorrhage of bronchial mucosa,and relaxes smooth muscles.Therefore,researches and clinical observation on the regulatory significance of meglumine adenosine cyclophosphate for cAMP/cGMP system may contribute to set forth the etiology of asthma and provide new theoretical basis and way for clinical treatment.Methods.The level of cAMP/cGMP in peripheral plasma of 22 children with asthma,both in acute stage and catabasis is detected by specific radioimmunoassay.Meanwhile 24 sex and age matched healthy children serve as the control.For those 19 children with meglumine adenosine cyclophosphate taken(5～10mg/Kg.d,for continuous 7 days)and 22 control patients receiving required treatment,peripherial plasma is gathered for the measurement of cAMP/cGMP.From all the children,1ml venous blood is extracted in the morning limosis,put into prefrozen tubes containing 50μl EDTA(10%),mixed abubdantly,centrifuged for 20 minutes under 4℃,and plasma is dripped and stroed under 20℃below zero for use.Radio-immunoassay kit from isotope institute of Shanghai second Chinese medical university is adopted and operated according to the instruction.Low-temperature centrifuge of LDR4—8.4℃type from Beijing medical centrifuge factory and EJ-2003 type full-automatic immune arithmometer from Xi'an 262 factroy are also introduced.Data analysis.All data are expressed as mean±standard deviation(SD). Significant differences between two groups are estimated by student's t-test andχ~2 test(Chi-square test)for categorical variable at specific time points.A P value of less than 0.05 indicates statistical significance.The SAS Version 6.0 program is used for all statistical calculations.Results- The level of cGMP of peripheral plasma in children with asthma of acute stage is significantly higher than that of the catabasis and the control(both P＜0.05),while the level of plasma cAMP lower(P＜0.05).The ratio of cAMP/cGMP in peripheral plasma of children with asthma of acute stage is statistically different form that of the catabasis and the control(both P＜0.05). With meglumine adenosine cyclophosphate administrated in the acute stage, elevated plasma level of cAMP and the ratio of cAMP/cGMP is detected,and decreased cGMP as well(P＜0.05).Conclusions.overexpression of plasma cGMP and insufficiency of cAMP consist in children with asthma,and the ratiop of cAMP/cGMP can serve as a biochemical target for monitoring and directing the treatment of asthma.Meglumine adenosine cyclophosphate medication is beneficient for the balance of cAMP/cGMP and the control of asthma.