ABSTRACT
BACKGROUND: Increasing evidence identifies the immune system not as an isolated system with automodulations, but one that interacts with the central nervous system.OBJECTIVE: To investigate the distribution of c-fos expression in the lung and brain tissues of asthmatic rats and explore is significance.DESIGN: Randomized controlled study.SETTING: Department of Oncology, Southern Hospital, and Department of Neurosurgery, Zhujiang Hospital, Southern Medical University.MATERIALS: The experiment was conducted Department of Oncology,Southern Hospital, and Department of Neurosurgery, Zhujiang Hospital,Southern Medical University, between January and August 2004. Fourteen healthy male rats were randomized into experimental group (n=10) and control group (n=4).METHODS: On the first day of experiment, the rats in experimental group received intraperitoneal injection of 2 mL of the suspension containing 10 mg albumen, 200 mg aluminum hydroxide powder and inactivated pertussis vaccine (5×109), and subjected to inhalation of ultrasonically atomized 10 g/L albumen from on the 15th day, 2 times per hour for totally 3 days, to induce asthma in the rats. The rats in the control group received intraperitoneal injection of 2 mL normal saline on the 1st day and inhalation of ultrasonically normal saline on the 15th day, 30 mL a day for totally 3 days. The lung and brain tissues of all the anesthetized rats were fixed by perfusion, and immunohistochemical method with ovin-biotin-peroxidase complex and imaging analysis system were used to observe the distribution of Fos protein in the lung and brain.MAIN OUTCOME MEASURES: Distribution of c-Fos protein in lung and cerebrum.c-Fos in the lung and brain tissues was obviously higher in asthmatic group than in the control group (P ＜ 0.05), located mainly in the parietal-fontal cortex, limbic forebrain (cingulum cortex, pyriform cortex and central amygdaloid nucleus and so on), thalamus paraventricular nucleus, hypothalamus paraventricular nucleus, supraoptic nucleus, lateral region of the hypothalamus, hypothalamus periventricular nucleus, nucleus of solitary tract,area postrema and ventrolateral medulla. No obvious Fos expression was observed in the cerebellum. A large number of c-Fos-positive cells were observed in the wall of the airway and lungs in asthmatic rats, mainly distributing in the mucous membrane and submucous layer and around the smooth muscles; in the control rats, no positive cells or only occasional cells with weak c-Fos positivity were found in the wall of the airway and lungs.CONCLUSION: c-Fos expression increases obviously not only in the lungs of asthmatic rats, but also in medullar and its ascending projecting nuclei (hypothalamus, amygdala and so on), suggesting that the expression of protooncogene c-fos might be closely related with neuroimmunomodulation in asthma.
