Inhibitory effect of cannabinoid agonists on gastric emptying in the rat

Abstract

We have studied the effect of WIN 55,212-2 (a psychoactive cannabinoid agonist), cannabinol (a nonpsychoactive cannabinoid agonist), SR141716A, a cannabinoid CB1 antagonist, and SR144528, a cannabinoid CB2 antagonist, on gastric emptying in the rat. WIN 55,212-2 (0.1-5 mg/kg, i.p.) and cannabinol (0.1-25 mg/kg, i.p.) dose-dependently delayed gastric emptying while SR141716A (1 mg/kg and 5 mg/kg) and SR144528 (1 mg/kg) were without effect. SR141716A (1 mg/kg), but not SR144528 (1 mg/kg), counteracted the inhibitory effect of the two cannabinoid agonists. These results suggest that cannabinoid agonists delay gastric emptying through activation of cannabinoid CB1 receptors, while the endogenous cannabinoid system does not seem to modulate gastric motility.

Angiotensin II-induced activation of central AT1 receptors exerts endocannabinoid-mediated gastroprotective effect in rats

“…Cannabinoids were shown to inhibit gastrointestinal motility (Izzo et al, 1999;Krowicki et al, 1999), gastric acid secretion (Adami et al, 2002) and development of gastric mucosal lesions both in acid-dependent (Germano et al, 2001;Rutkowska and Fereniec-Goltbiewska, 2006) and acid-independent ulcer models (Shujaa et al, 2009). Accordingly, CB 1 receptors were identified in neurons of the enteric nervous system and in sensory terminals of vagal and spinal neurons, moreover, CB 1 receptors are also identified in the dorsal vagal complex: in the nucleus of the solitary tract (NTS) (Partosoedarso et al, 2003), in the dorsal motor nucleus of vagus (DMNV) (Mackie, 2005) and prominently, in the area postrema (Mackie, 2005).…”

Antidiarrheal mechanism ofCarpolobia lutealeaf fractions in rats

“…An inhibitory action on intestinal transit, as elicited by the ethyl acetate fraction in this study, delays the passage of gastrointestinal contents and allows feces to become desiccated, thus further retarding movement through the colon (Akindede & Adeyemi, 2006). The effect of C. lutea in reducing intestinal propulsion is linked to delay in gastric emptying, as observed for the case with atropine and morphine (Izzo et al, 1999;Akindele & Adeyemi, 2006). The dose 770 mg/ kg of ethyl acetate fraction inducing 100% inhibition of IPM is critical as other doses (median or lower) did not produce significant dose-dependent inhibition of gastric emptying (unpublished data).…”

Antidiarrheal activity of methanolic leaf extract of <i>Rumex vesicarius</i>

“…One mL of the marker (10% charcoal suspension in 5% gum acacia) was administered orally 1 hour after castor oil treatment. The rats were sacrificed after 1 hour and the distance traveled by the charcoal meal from the pylorus was measured and expressed as the percentage of the total length of the intestine from the pylorus to cecum (Izzo et al, 1999).…”