Hypothalamic Paraventricular Injections Of Substance P: Neuroimmunomodulation Effects On Asthma Rat

【Objection】To explore the neuroimmunomodulatory role of Substance P(SP) and its antagonist S0145 in hypothalamic paraventricular nuclei (PVN) on asthma onset and its possible mechanism in the rats.【Methods】Male SD rats were grouped as control and experiment. The experiment group were sensitized by ovalbumin(OA) saline, then they were inserted a steel tube into PVN according to the rat brain atlas. After challenged by OA intravenously, SP and (or) S0145 was microinjected into PVN. Change in pulmonary function, immunological function, and morphology were tested. The control group were injected with saline in the same site as experiment group.【Results】1)After challenged by OA saline intravenously, the rats suffered by a typical asthma attack for more than 60 minutes, as observed with pulmonary function and histopathological test. The concentration of SP in PVN increased after asthma attack. 2)In sensitized rats, microinjection with SP into PVN worsened asthma attack, as assessed pulmonary function, immunological function and neurogenic inflammation. Microinjection with S0145 inversed these actions, and microinjection with SP followed with S0145 induced no change. 3)Microinjection of SP into PVN enhanced Fos expression in PVN, DMV and NTS after challenge, and microinjection of S0145 into PVN depressed their expression.【Conclusion】These data suggest that SP in PVN play a neuroimmunomodulatory role on asthma via DMV - vagus by regulating immunogical function, neurogenic inflammation and pulmonary function.