Carbachol induces TGF-alpha expression and colonic epithelial cell proliferation in sensory-desensitised rats

Roles of substance P and ATP in the subepithelial fibroblasts of rat intestinal villi

The ingestion of food and water induces chemical and mechanical signals that trigger peristaltic reflexes and also villous movement in the gut. In the intestinal villi, subepithelial fibroblasts under the epithelium form contractile cellular networks and closely contact to the varicosities of substance P and nonsubstance P afferent neurons. Subepithelial fibroblasts of the duodenal villi possess purinergic receptor P2Y1 and tachykinin receptor NK1. ATP and substance P induce increase in intracellular Ca(2+) and cell contraction in subepithelial fibroblasts. They are highly mechanosensitive and release ATP by mechanical stimuli. Released ATP spreads to form an ATP "cloud" with nearly 1μM concentration and activates the surroundings via P2Y1 and afferent neurons via P2X receptors. These findings suggest that villous subepithelial fibroblasts and afferent neurons interact via ATP and substance P. This mutual interaction may play important roles in the signal transduction of mechano reflex pathways including a coordinate villous movement and also in the maturation of the structure and function of the intestinal villi.

[Establishment of Orthotopic Xuanwei lung cancer SCID mouse model and analysis of biological properties]

背景与目的

宣威女性肺癌发病率居全国首位，亟待深入探讨其发病机制。本研究拟建立SCID小鼠原位宣威肺癌模型，为该病的深入研究提供实验平台。

方法

将宣威肺癌细胞XWLC-05分别以高低剂量接种于SCID小鼠肺原位，并与皮下移植瘤比较，观察成瘤率、成瘤特性、自发性转移及生存情况。

结果

原位移植高低剂量组的成瘤率分别为81%和83%，其中高剂量组接种后13天小鼠出现恶液质、对侧肺及胸腔的广泛粘连，无远处转移；低剂量组接种后25天小鼠出现恶液质及远处转移。皮下移植高低剂量组成瘤率分别为100%及94.5%，无远处转移。原位移植组组内及皮下与原位移植组组间的转移率存在统计学差异（P < 0.05）。两组组内和组间的生存率比较有统计学差异（P < 0.001）。

结论

成功建立了宣威肺癌的SCID小鼠原位动物模型，为该病的深入研究奠定了实验基础。