[Expression of aquaporin 3, 4, and 8 in colonic mucosa of rat models with slow transit constipation].

Objective: To investigate the expression of aquaporin 3, 4, and 8 in the colonic mucosa of rat models with slow transit constipation (STC).

Methods: STC rat model was established by giving the rats the compound solution of diphenoxylate. Real time polymerase chain reaction (RT-PCR) was used to measure the expression of aquaporin mRNA in colonic mucosa of STC rat models (study group,n=16) and normal rats (control group,n=16). Gray scale ratio of aquaporin to β-action (internal reference) was used for quantification.

Results: RT-PCR revealed that the mean gray scale ratios of aquaporin 3 in the proximal colon of the study group and control group were 0.344 and 0.602 (P<0.05), and were 0.419 and 0.509 in the distal colon (P>0.05), respectively. The mean gray scale ratios of aquaporin 4 in the proximal and the distal colon were 0.764 and 0.759 in the study group (P>0.05), and were 0.776 and 0.736 in the control group (P>0.05), respectively. However, there was no expression of aquaporin 8 in the proximal and the distal colon in either the study group or the control groups.

Conclusions: Expression of aquaporin 3 in the proximal colon of STC rat models is down-regulated, which regulates water absorption. There are no significant changes in the expressions of aquaporin 4 and 8.