水通道蛋白3在慢传输型便秘模型大鼠结肠黏膜中的表达

Expression of aquaporin-3 in colon mucosa of rats with slow transit constipation

目的通过复制大鼠慢传输型便秘(STC)模型,观察水通道蛋白3(AQP3)在模型大鼠结肠黏膜中的表达,进而探讨其与STC的关系。方法将40只SD大鼠随机分为空白组和模型组,各20只。模型组灌胃盐酸洛哌丁胺10 mg/kg,空白组灌胃等容量SPF级实验动物饮用水,2组均1次/d,连续灌胃42 d。实验期间各组大鼠自由进食、饮水,观察大鼠的一般状态并检测体质量变化;造模第40天检测首粒黑便排出时间;第42天计算小肠推进率,并对结肠组织进行免疫组化染色,显微镜下观察AQP3阳性染色情况,计算平均积分光密度(IOD)、平均光密度(OD)及模型组的增加率。结果造模第4,5,6周,与空白组比较,模型组大鼠体质量增长均显著减慢(P<0.05或P<0.01)。模型组第4周左右开始出现固体硬质粪便,粪便成球形、锥形或串珠样,质硬、表面少有光泽。首粒黑便排出时间显著延长(P<0.05或P<0.01),但小肠推进率与空白组比较差异无统计意义(P>0.05)。模型组大鼠结肠黏膜吸收细胞和杯状细胞呈棕褐色,染色明显;模型组大鼠AQP3表达水平显著增加,OD和IOD增加率分别为11.1%,118.5%,与空白组比较,差异均有高度统计意义(P<0.01)。结论 STC模型大鼠近端结肠黏膜上都有AQP3的表达,且可能在STC的发生、发展中起一定的作用。

Objective To observe the expression of aquaporin-3 in colon mucosa of model rats with slow tran- sit constipation （STC） and explore the correlation. Methods 40 SD rats were randomly divided into control group and model group ,20 cases each group. The model group was given loperammide hydroehloride （10 mg/kg） by ga- vage;the control group was perfused with the same dosage of SPF laboratory animal drinking water;once a day,la- sting for 42 days. General condition and body weight were observed and measured. On 40th day, the first defecations time was recorded ; on 42＂~, small intestinal propulsion rates were measured. The expression of aquaporin-3 was ob- served through immunohisto-chemical staining method. IOD, OD and increasing rate were calculated. Results On 4th ,5th and Ch week, compared with control group, increase of body weight in model group slowed down obviously （P〈O. 05 or P〈0.01 ）. On 4th week, rats in model group defecated hard and dark faeces in spherical, cone or beads-on-string shape. The first defecations time was significantly extended （P〈0.05 or P〈O. 01 ）. As to intestine advance rate,there was no any significant difference between two groups （P〉0.05）. Absorptive cells and goblet cells in colon mucosa were stained in brown. The levels of aquaporin-3 expression of model rats increased. Increa- sing rates of IOD and OD were 11.1% and 118.5% respectively. Compared with control group,the difference was significant （P〈0.01）. Conclusion The expression of aquaporin-3 in proximal colon mucosa may play an impor- tant role in the incidence and development of STC.