Wu Yuqing, Hu Jue, Zhang Rongjian, Zhou Chenghua, Xu Youhua, Guan Xiaowei, Li Shengnan
Department of Pharmacology, Nanjing Medical University, Nanjing, PR China.
Cell Physiol Biochem. 2008;21(1-3):173-82. doi: 10.1159/000113759. Epub 2008 Jan 16.
Corticotropin-releasing factor (CRF), which activates the hypothalamic-pituitary- adrenal axis under stress, also has proinflammatory peripheral effects possibly through mast cells. The purpose of this study was to investigate the effect of urocortin (UCN), a 40-amino-acid CRF family peptide, on degranulation and intracellular calcium of rat lung mast cells. The activation and degranulation of mast cells were observed by Toluidine blue staining and transmission electron microscope. The intracellular calcium was investigated using confocal laser scanning microscopy and flow cytometry. The results indicated that all the three different concentrations of UCN (0.1, 1 and 10 microM) significantly induced the activation and degranulation of rat lung mast cells in vitro. This effect was markedly blocked by selective CRF receptor 1 (CRF-R1) antagonist antalarmin, but not by specific CRF receptor 2 (CRF-R2) antagonist antisauvagine-30 (anti-Svg-30). The results also showed that UCN caused a rapid peak increase in Ca(2+) at point of 300s after UCN treatment, followed by a decrease to a sustained plateau phase. The peak increase in Ca(2+) induced by UCN was significantly inhibited by antalarmin, but not by anti-Svg-30. This effect of UCN on Ca(2+) in rat lung mast cells was also found by flow cytometry. Regression analysis revealed a positive correlation between mast cells degranulation extent and the maximum value of Ca(2+) (P < 0.01). Taken together, our present study suggested that UCN induced the increase of Ca(2+) and degranulation of rat lung mast cells through CRF-R1. These findings may have implications for the pathophysiology of allergic and inflammatory lung disorders such as asthma, which is closely associated with mast cell activation and degranulation.
促肾上腺皮质激素释放因子（CRF）在应激状态下激活下丘脑 - 垂体 - 肾上腺轴，其也可能通过肥大细胞产生促炎的外周效应。本研究的目的是探讨尿皮质素（UCN，一种40个氨基酸的CRF家族肽）对大鼠肺肥大细胞脱颗粒和细胞内钙的影响。通过甲苯胺蓝染色和透射电子显微镜观察肥大细胞的活化和脱颗粒情况。使用共聚焦激光扫描显微镜和流式细胞术研究细胞内钙。结果表明，三种不同浓度的UCN（0.1、1和10微摩尔）均能在体外显著诱导大鼠肺肥大细胞的活化和脱颗粒。这种效应被选择性CRF受体1（CRF - R1）拮抗剂安他乐明显著阻断，但未被特异性CRF受体2（CRF - R2）拮抗剂抗 sauvagine - 30（anti - Svg - 30）阻断。结果还显示，UCN处理后300秒时细胞内钙离子浓度（Ca(2 +)）迅速达到峰值然后升高，随后下降至持续平台期。UCN诱导的Ca(2 +)峰值升高被安他乐明显著抑制，但未被anti - Svg - 30抑制。流式细胞术也发现了UCN对大鼠肺肥大细胞Ca(2 +)的这种作用。回归分析显示肥大细胞脱颗粒程度与Ca(2 +)最大值之间呈正相关（P < 0.01）。综上所述，我们目前的研究表明，UCN通过CRF - R1诱导大鼠肺肥大细胞Ca(2 +)升高和脱颗粒。这些发现可能对过敏性和炎性肺部疾病如哮喘的病理生理学有影响，哮喘与肥大细胞活化和脱颗粒密切相关。
