Change in substance P-induced edema in rat trachea : a digital photomicrography and 3-dimensional reconstruction study

• Main Authors: Shih-chieh Chen, 陳仕傑
• Other Authors: Hung-Tu Huang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/93393236571200128898

碩士 === 國立中山大學 === 生物科學系研究所 === 93 === Intravenous application of high dose of capsaicin to the rat stimulates C-fiber neurons that innervate the airways to release tachykinins that produce acute inflammation in the mucosal tissue. Large amount of extravasated plasma is retained underneath the tracheal epithelium to form edema. Substance P (SP) is the most important inflammation-producing peptide of tachykinin family. The present study was to investigate time-dependent formation and remission of edema induced by SP (3 µg/ml/kg) by the use of digital morphometric analysis of montages of tracheal cross sections. Furthermore, 3-dimensional reconstruction of serial tracheal sections was carried out to analyze the relative distribution of subepithelial edematous loci. Two edema indexes were designated for evaluation of the status of edema. Edema length ratio was the ratio of the total length of edematous loci to the circumference of a tracheal section. Edema area ratio was the ratio of the total area of edematous loci to the area of tracheal epithelium and associated edema. The degree of edematous status in the mucosa exhibited a time-dependent change. Five min after application of SP, edema length ratio and edema area ratio in the trachea were 35.80±1.42% and 16.28±2.51%, that were 7.6 and 7.9 times, respectively, the values of vehicle control group. At 1 h after SP, edema length ratio and edema area ratio declined to 16.40±2.46% and 8.00±1.60%, 2.2 and 2.8 times the values of control, but still significantly different (P < 0.05). At 24 or 72 h after SP, the values of edema were not significantly different (P > 0.05) from the control values. Three- dimensional reconstruction study showed that, in the trachea of rats 5 min after receiving SP, there were many subepithelial edematous loci, evenly distributed along the inner circumference of trachea. They were interconnected. The number of edematous loci decreased drastically by 1 h after SP. Loci of edema were rarely found 24 or 72 h after SP. The close association of edema to the tracheal epithelium suggests that the mucosal surface may be the site for elimination of edema fluid.