Auramine-O Enhances Small Intestinal Transit in Male Albino Rats

Auramine O (AO), a synthetic diarylmethane dye, is widely used in various industrial applications but is increasingly scrutinized for its potential toxicological effects on biological systems. Therefore, the present study aimed to investigate the effects of AO on the gastrointestinal transit in male albino rats. Using a charcoal meal test to assess motility of the small intestine, we evaluated the effects of AO on the contractions of the visceral smooth muscles situated at the wall structure of the small intestine. The percentage of intestinal transit was calculated and compared among the groups. We observed a significant increase in gastrointestinal transit percentages in groups of rats exposed to AO compared to control rats suggesting enhanced small intestinal motility. This result suggest that AO facilitates the contraction of the small intestinal smooth muscles thus increasing small intestinal motility. This AO induced facilitation of the contraction of the SiVSM might be due to cholinergic pathway activation which in turn increases the percent small intestinal transit. Keywords: Auramine O (AO), gastrointestinal transit, acetylcholine, atropine, cholinergic pathway, motility