长期慢性束缚水浸应激对大鼠胃窦Cajal间质细胞数量的影响

Long-term chronic water immersion-restraint stress alters the number of interstitial cells of Cajal in the gastric antrum of rats

目的:研究不同时程低强度束缚水浸应激对大鼠Cajal间质细胞(interstitial cells of Cajal,ICC)数量的影响,探讨慢性应激导致胃动力改变与ICC的相关性.方法:雄性SPF级SD大鼠48只被随机分为6组,即实验3d、7d、28d组和对照3d、7d、28d组,每组8只.实验组23℃水域箱内束缚水浸1h/d,对照组自由摄食饮水.4d、8d、29d晨序贯脱颈处死.取膜胃小弯侧(ICC-1)、腺胃小弯侧(ICC-3)、腺胃大弯侧上1/3处(ICC-5)、腺胃幽门旁0.5cm处(ICC-7)组织各一块放入固定液中,制成石蜡切片;抗c-kit免疫组织化学染色,观察不同层次ICC计数.结果:正常大鼠胃内ICC主要分布在肌内(ICC-MY)和肌间(ICC-IM),而黏膜下(ICC-SM)和深肌丛(ICC-DMP)较少.实验3d组的各层ICC数量与对照组相比无明显差异,实验7d和28d组大鼠不同部位、不同层次及同一部位不同层次ICC数量明显异于同期对照组.应激时间长短对不同部位不同层次及同一部位不同层次ICC总数有明显影响,其大致规律是先正常后增加再减少,即先升高后降低.应激主要引起ICC-MY及ICC-IM数量发生变化,而本来较少的ICC-SM和ICC-DMP受影响较轻.结论:长时间低强度的慢性束缚水浸应激可以使大鼠胃窦ICC数量发生变化.

AIM： To investigate the impact of long-term chronic water immersion-restraint stress on the number of interstitial cells of Cajal （ICC） in the gastric antrum of rats and to explore the relationship between ICC and gastric motility changes caused by chronic stress. METHODS： Forty-eight male Sprague-Dawley rats were randomly and equally divided into six groups： three experiment groups and three matched control groups. The three experimental groups underwent water immersion-restraint stress for one hour daily for 3, 7 and 14 d, respectively, while the three control groups were allowed free access to food and water. On days 4, 8 and 29, the rats in both groups were sacrificed. Gastric tissue samples were collected from areas at the lesser curvature of the membranous stomach and the lesser curvature of the glandular stomach as well as areas near the upper one third of the great curvature of the glandu- lar stomach and the pylorus of the glandular stomach. Paraff in-embedded sections were then made. The number of ICC was counted after immunohistochemical staining for c-Kit. RESULTS： Intermuscular （ICC-MY） and intramuscular ICC （ICC-IM） were predominant types of ICC in normal rats, whereas submucosal ICC （ICC-SM） and ICC in the deep muscular plexus （ICC-DMP） were minor ones. The number of ICC were statistically different between the experiment and control groups on days 7 and 28 after stress： the number of ICC increased on day 7 but decreased on day 28 in the experiment groups. After stress, significant changes were found in the number of ICC-MY and ICC-IM, but not in that of ICC-SM and ICC-DMP. CONCLUSION： Long-term chronic water immersion-restraint stress alters the number of ICC in the gastric antrum of rats.