mRNA expression of aquaporin protein 1 and 7 in rat model of slow transit constipation (STC)

Water channels play important role in colon, and might be involved in constipation disease. To understand the mRNA expression changes of aquaporin protein 1 and 7 (AQP1, AQP7) in a rat model of slow transit constipation (STC), a rat model of slow transit constipation was designed, and the correlated changes of aquaporin protein 1 and 7 at the mRNA level were examined. The rat model of slow transit constipation was produced with diphenoxylate administration. The mRNA expression of AQP1 and 7 from STC rats and control rats were examined with reverse transcription polymerase chain reaction (RT-PCR). AQP1 was expressed in ascending and descending colon of both control and STC rats. For the ascending colon, the AQP1 grayscale ratio in control and STC rats were 0.602 ± 0.239 and 0.344 ± 0.212 (P 0.05), respectively in descending colon. AQP7 was also expressed in ascending and descending colon of both control and STC rats, with 0.776 ± 0.642 and 0.764 ± 0.147 in ascending colon (P > 0.05), and 0.736 ± 0.42 and 0.759 ± 0.629 in descending colon (P > 0.05), respectively. We did not examine the changes of the AQPs at the protein level. The downregulation of AQP1 rather than AQP7 might be involved in the development and progression of STC.