Endocannabinoids and the gut.

In the digestive tract, there is evidence for the presence of high amounts of endocannabinoids (anandamide and 2-arachidonylglycerol) and of mechanisms for endocannabinoid metabolism and possibly endocannabinoid uptake. Pharmacological studies have shown that anandamide inhibits excitatory transmission and peristalsis in the isolated guinea-pig ileum and reduces intestinal motility in the mouse in vivo; all these effects are mediated by CB(1) receptors, which are located on enteric nerves. Conversely, the selective CB(1) receptor antagonist SR141716A increased intestinal motility and this effect is likely due to the displacement of endocannabinoids rather than to its inverse agonist properties. Interestingly, inhibitory effects of anandamide via non-CB(1) receptors and stimulatory effects via vanilloid receptors have also been proposed. Copyright 2002 Elsevier Science Ltd. All rights reserved.