Abstract
Background & Aims: There is an ongoing discussion concerning the role of bile salts on the gastrointestinal motility. Therefore, Taurodeoxycholic acid (TDCA) was studied to investigate the effect of TDCA on mice colonic motility and to examine this mechanism of action in presences histamine antagonist (pyrilamine maleate salt, H1) and serotonin agonist (5-hydroxytryptamine hydrochloride, 5-HT).
Methods: Dose response curve of TDCA was performed using different doses of TDCA (0.3, 30, 50, 100, 200, 300 and 500 mu M). Peristaltic motor complexes (PMCs) amplitudes and intervals of contractions were recorded. TDCA inhibitory effect (300 mu M) on PMCs was studied with presence with H1 (10 mu M) and 5-HT (25 mu M).
Results: TDCA inhibits intestine motility through increasing PMC intervals and decreasing PMC amplitudes with doses of 100, 200, 300 and 500 mu M compared to the control values (P < 0.03, 0.03, 0.01, 0.01 respectively). H1 antagonist (10 mu M) induced significant reducing in the PMC intervals (137.2 +/- 13 S) compared to the control values (255.8 +/- 31 S, P < 0.04) while there was no response of 5-HT agonist (25 mu M) on interval or amplitude of PMCs regardless applying of TDCA (300 mu M).
Conclusion: TDCA directly inhibited colon motility may be due to slowing intestinal transit time. These finding is not revealed with presences of histamine antagonist and serotonin agonist.