[Establishment and effect observation on three kinds of Ti-Xu with constipation rat models]

To establish three types constipation models with the syndrome of Xue-Xu, Yin-Xu and Yang-Xu in rats, and to compare the difference of colonic motility, colonic water metabolism, colonic mucus secretion and the level of aquaporin-2 (AQP2).

Forty Sprague Dawley rats, male and female in half, were randomly divided into four groups:normal control group(N), Xue-Xu with constipation group(XC), Yin-Xu with constipation group(YC) and Yang-Xu with constipation group(YAC). Bloodletting and loperamide were used to induce the Xue-Xu with constipation in rats, thyroxin and loperamide were used to induce the Yin-Xu with constipation in rats, ice-water stimulation and loperamide were used to induce the Yang-Xu with constipation in rats. Bloodletting was coducted once a week,drug was ad-ministrated orally to rats once a day for continuous 42 days. Rats'state, body weights, stool character, transfer time between mouth and anal, small intestinal propulsion rate were measured. The colon tissues of rats were stained with alcian blue-periodic acid schiff (AB-PAS) to analyze the changes of mucus secretion. The aquaporin-2 expressions in proximal and distal colon of rats were measured by immunohistochemical method.

Compared to normal control group, weight-increasing speed of the rats were reduced in three models. The order of indepen-dent movement change was YC, XC and YAC. Solid stool appeared at 30 d, fecal scores were increased. Transfer time between mouth and anal was significantly extended, small intestinal propulsion rate were significantly decreased(P < 0.05, P < 0.01). Water content in stool were significantly decreased in three type models(P < 0.05, P < 0.01), the content of water in colon were decreased in XC and YAC group (P < 0.05, P < 0.01). The colonic gland and goblet cells were narrowed in some extent, the mucus excretion were decreased. The levels of aquaporin-2 expressions in proximal and distal colon of rats were increased(P < 0.05, P < 0.01), increasing order of AQP2 expression in proximal colon was YAC, YC and XC, increasing order of AQP2 expression in distal colon was YAC, XC and YC.

Long term stimulation of complex factors could induce Ti-Xu with constipation animal model, and there were some differences in colonic motility, water metabolism, colonic mucus secretion and AQP2 in rats.