Inhibitory effect of heat shock on endotoxin-induced inflammation and secretion in rat small intestine

• Main Authors: Man-ni Chiu, 邱曼妮
• Other Authors: Hung-tu Huang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/w26ur3

碩士 === 國立中山大學 === 生物科學系研究所 === 95 === The gastrointestinal epithelium normally sealed by tight junctions, which act as a structural barrier and paracellular channels. Inflammation can increase the permeability of microvasculature that result in plasma leakage. Mammalian intestinal epithelium has many goblet cells which discharge mucus in the inflammatory response. The discharging mucus functioning is as a defensive barrier and lubricant. The mucus layer is the anatomical site at which the host first encounters gut bacteria, physical damage, and chemical stimulant. The heat shock response is one of the most primitive cellular defense mechanism. A variety of stressful situations including environmental (ultraviolet radiation or heavy metals), pathological (infections or malignancies), or physiological (growth factors) stimuli induce heat shock proteins. This study investigated the effect of heat shock on endotoxin-induced plasma leakage and goblet cell mucus discharge in the small intestine of rats of Sprague-Dawley (SD) and Long-Evans (LE) strains. India ink was used as the tracer to detect leaky microvessels. The mucus secretion of the goblet cells of intestinal villi was observed with scanning electron microscopy and calculated with digital morphomertric software SimplePCI. Our results showed that endotoxin-induced plasma leakage and goblet cell discharging in the two strains increased significantly as compared to rat groups receiving saline. Numerous openings on the epithelial surface of villi resulted from compound exocytosis of mucus granules in goblet cells. Either 30 min or 1h after LPS injection, heat shock pretreatment in LE rats LPS-induced plasma leakage in the duodenum and ileum was reduced by 58-80% (P<0.01). 1 h after LPS injection in LE rats pretreated with heat shock, the number of discharging goblet cells in the ileum was reduced (P<0.05). In SD rats, heat shock inhibited LPS-induced plasma leakage in the duodenum and ileum at 1h after LPS injection by 56-68% (P<0.01), and the number of discharging goblet cells was reduced in the duodenum and ileum (P<0.05). In conclusion, heat shock could protect rat intestine from endotoxin-induced inflammation and mucus secretion.