Expression of aquaporin 1 in colonic mucosa of rats with slow transit constipation

Objective To investigate the expression of aquaporinl in colonic mucosa of rats with slow transit constipation (STC),and its role in the pathologenesis of STC.Methods Thirty-two SpragneDawley rats were randomly divided into two groups:control group (n =16) and STC group (n =16).STC model was created by giving the rats the solution of compound diphenoxylate.The reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect the expression of apuaporin 1 (AQP1) mRNA in colonic mucosa of rats with STC (trial group) and the normal rats (control group).Results The fecal mass of STC rats was (1.279 ± 0.743) g/100 g,significantly less than that in the normal rats [(1.571 ±0.783) g/100 g] (P ＜ 0.05).In STC rats,the time of discharge of the first black fecal was 461.6 ±150.8 min,significantly longer than that in the normal rats [(351.3 ± 119.9) min] (P ＜ 0.05).RT-PCR revealed that the average values of gray scale ratios of AQP1 in proximal colon of trial group and control group were 0.281 ± 0.212 and 0.502 ± 0.239 respectively (P ＜ 0.05).The average values of gray scale ratios of AQP1 in distal colon of trial group and control group were 0.429 ± 0.309 and 0.509 ± 0.308 respectively (P ＞0.05).Conclusion Expression of AQP1 in proximal colon of rats with STC was downregulated,which may play roles in water absorption. Key words: Aquaporin;  Slow transit constipation