A sexually dimorphic effect of cholera toxin: rapid changes in colonic motility mediated via a 5-HT3 receptor-dependent pathway in female C57Bl/6 mice

Abstract

KEY POINTS: Cholera causes more than 100,000 deaths each year as a result of severe diarrhoea, vomiting and dehydration due to the actions of cholera toxin; more females than males are affected. Cholera toxin induces hypersecretion via release of mucosal serotonin and over-activation of enteric neurons, but its effects on gastrointestinal motility are not well characterized. We found that cholera toxin rapidly and reversibly reduces colonic motility in female mice in oestrus, but not in males or females in prooestrus, an effect mediated by 5-HT in the colonic mucosa and by 5-HT3 receptors. We show that the number of mucosal enterochromaffin cells containing 5-HT changes with the oestrous cyc..