Background Cannabinoid (CB) receptors are involved in the regulation of gastrointestinal (GI) motility under physiological and pathophysiological conditions. We aimed to characterize the possible influence of CB1 and CB2 receptors on motility impairment in a model of septic ileus.
Methods Lipopolysaccharide (LPS) injections were used to mimic pathophysiological features of septic ileus. Spontaneous jejunal myoelectrical activity was measured in rats in vivo, and upper GI transit was measured in vivo by gavaging of a charcoal marker into the stomach of mice, in absence or presence of LPS, and CB1 and CB2 receptor agonists and antagonists. Tumour necrosis factor (TNF)-α and interleukin (IL)-6 levels were measured using enzyme-linked immunosorbent assay. Histology was performed with haematoxylin–eosin staining.
Key Results Lipopolysaccharide treatment significantly reduced amplitude and frequency of myoelectric spiking activity and GI transit in vivo in a dose-dependent manner. TNF-α and IL-6 were increased in LPS-treated animals and histology showed oedema and cell infiltration. Both, the CB1 agonist HU210 and the CB2 agonist JWH133 reduced myoelectrical activity whereas the CB1 antagonist AM251 caused an increase of myoelectrical activity. Pretreatment with AM251 or AM630 prevented against LPS-induced reduction of myoelectrical activity, and also against the delay of GI transit during septic ileus in vivo.
Conclusions & Inferences The LPS model of septic ileus impairs jejunal myoelectrical activity and delays GI transit in vivo. Antagonists at the CB1 receptor or the CB2 receptor prevent the delay of GI transit and thus may be powerful tools in the future treatment of septic ileus.