piperidines and Jejunal-Diseases

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 CB(1) and CB(2) 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 CB(1) and CB(2) receptor agonists and antagonists. Tumour necrosis factor (TNF)-alpha 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-alpha and IL-6 were increased in LPS-treated animals and histology showed oedema and cell infiltration. Both, the CB(1) agonist HU210 and the CB(2) agonist JWH133 reduced myoelectrical activity whereas the CB(1) 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 CB(1) receptor or the CB(2) receptor prevent the delay of GI transit and thus may be powerful tools in the future treatment of septic ileus.

Topics: Analysis of Variance; Animals; Cannabinoids; Dose-Response Relationship, Drug; Dronabinol; Electrophysiology; Enzyme-Linked Immunosorbent Assay; Gastrointestinal Motility; Gastrointestinal Transit; Ileus; Interleukin-6; Jejunal Diseases; Jejunum; Lipopolysaccharides; Male; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Sepsis; Tumor Necrosis Factor-alpha

Distension of the rat intestine causes a depressor response which is predictive of nociception. This study investigated the effects of previous infection with Nippostrongylus (N.) brasiliensis on the sensitivity to intestinal distension and the role of tachykinin NK2 receptors. The tachykinin NK2 receptor antagonist, SR48968 (S)-N-methyl-N[4-(4-acetylamino-4-phenylpiperidino)-2-(3,4-dichloropheny l)butyl]benzamide) inhibited the nociceptive response (ED50 = 0.7 mg/kg) in control rats. In post-N. brasiliensis-infected rats sensitivity to intestinal distension was increased which was accompanied by an increase in the apparent potency value of SR48968 (ED50 = 0.1 mg/kg). The hypersensitivity was limited to areas of hypermastocytosis. It is concluded that the post-inflammatory changes that occur in post-infected rats increase visceral sensitivity and the apparent potency of tachykinin NK2 receptor antagonists.

Topics: Animals; Benzamides; Colon; Colonic Diseases; Dilatation, Pathologic; Intestinal Diseases, Parasitic; Jejunal Diseases; Jejunum; Male; Mast Cells; Nippostrongylus; Pain Measurement; Peroxidase; Piperidines; Rats; Rats, Wistar; Receptors, Neurokinin-2; Strongylida Infections