Résumé
Aim To investigate the role of substance P in the brain of asthmatic rats.Methods Rats were injected with aluminum hydroxide and OVA allergens to prepare the animal model of asthma. Then the content of c-fos protein in asthmatic rats' brain was detected by immunohistochemical method (SABC).The content of substance P in paraventricular nucleus (PVN), the content of corticotropin-releasing hormone (CRH) in median eminence (ME), and the content of adrenocorticotropic hormone (ACTH) and corticosterone (CORT) in peripheral blood were detected by radioimmunoassay method. Then exogenous SP, SP receptor antagonist S0145 were microinjected in PVN to observe their effect upon lung function and HPA axis in asthmatic rats. Results In asthmatic rats, the content of SP increased within the PVN. The content of CRH, ACTH and CORT decreased (P<0.05).The ratio of expiratory and inspiratory and airway resistance increased. Diaphragm discharge points and lung compliance decreased (P<0.01).After microinject of SP in PVN, there was a further decrease in pulmonary function and the content of CORT, ACTH and CRH in asthmatic rats (P<0.01).While the SP receptor antagonist S0145 might reverse the change of lung function and hypothalamus-pituitary-adrenal axis (HPA axis) in asthmatic rats.Conclusion In asthmatic rats the SP in PVN can affect the function of HPA axis, involved in asthma attacks.