Bisphenol A Inhibits The Motor Function Of Duodenal Smooth Muscle In Rat

Abstract

The aim of the present study was to examine the effect of BPA (50mg/kgBW/day for 20 and 30 days exposure period) on the movement of duodenum in rat model. It was observed that BPA significantly depresses the amplitude and frequency of duodenal movements in test animals of both exposure groups. Besides, the activity of acetylcholinesterase (AChE) of duodenal tissue homogenate was also increased significantly in test animals. From the results it is suggested that BPA inhibits the movement of duodenum presumably by inducing the activity of AChE in smooth muscle membrane. We also found significant facilitation in nitric oxide synthase (NOS) expression and increase in deposition of calcium salts in Von Kossa’s stained duodenal smooth muscle tissue section in test animals. From the results we may suggest that BPA may inhibit the duodenal movement by facilitating the synthesis of nitric oxide (NO) and decreasing the availability of free Ca2+ in duodenal smooth muscle cells. In order to study the BPA induced oxidative stress in duodenal smooth muscle, we have measured the oxidative stress indices in duodenal tissue homogenate. We found that BPA significantly decreases the activity of antioxidant enzymes. Thus, we may conclude that BPA inhibits the motor function of duodenal smooth muscle presumably by inducing oxidative stress, decreasing the availability of free Ca2+, inducing the activity of AChE and promoting the synthesis of NO in duodenal smooth muscle cells.