Medeiros Marta V, De Luca Iara M S, Bricola Alice A O, Zanesco Angelina, De Nucci Gilberto, Antunes Edson
Department of Pharmacology, Faculty of Medical Sciences, UNICAMP, 13081-970, (SP), Campinas, Brazil.
Neurosci Lett. 2003 May 1;341(2):103-6. doi: 10.1016/s0304-3940(03)00161-7.
This study aimed to investigate the in vivo and in vitro reactivity of airway smooth muscle in rats depleted of sensory neuropeptides by treatment with capsaicin at neonatal stage. Wistar rats were neonatally injected with either capsaicin (50 mg/kg, s.c., 2nd day of life) or its vehicle (10% ethanol and 10% Tween 80, in 0.9% w/v NaCl solution) and used at adult ages (60-70 days later). Analysis of the lungs showed a higher number of infiltrating neutrophils, eosinophils and mononuclear cells into the peribronchiolar regions of capsaicin-pretreated rats compared to vehicle group. This was associated with a higher contraction index of bronchiolar wall in the capsaicin group. The in vitro tracheal reactivity in response to methacholine (full muscarinic agonist) and pilocarpine (partial muscarinic agonist) was also significantly higher in capsaicin-pretreated rats compared to vehicle group. In conclusion, the neuropeptide depletion by capsaicin neonatal treatment lead to marked contraction of the rat airways at adult age, suggesting a protective role for C fibers in the lungs.
本研究旨在探讨新生期用辣椒素处理使感觉神经肽耗竭的大鼠气道平滑肌的体内和体外反应性。将新生Wistar大鼠皮下注射辣椒素（50 mg/kg，出生后第2天）或其赋形剂（0.9% w/v NaCl溶液中的10%乙醇和10%吐温80），并在成年期（60 - 70天后）使用。肺组织分析显示，与赋形剂组相比，辣椒素预处理大鼠的细支气管周围区域浸润的中性粒细胞、嗜酸性粒细胞和单核细胞数量更多。这与辣椒素组细支气管壁的收缩指数更高有关。与赋形剂组相比，辣椒素预处理大鼠对乙酰甲胆碱（完全毒蕈碱激动剂）和毛果芸香碱（部分毒蕈碱激动剂）的体外气管反应性也显著更高。总之，新生期用辣椒素处理导致神经肽耗竭，使成年大鼠气道出现明显收缩，提示肺内C纤维具有保护作用。
