Canna~Fangled Abstracts

2-arachidonoylglycerol interferes with lithium-induced vomiting in the house musk shrew, Suncus murinus

By August 22, 2013No Comments
  • Department of Psychology and Neuroscience Graduate Program, University of Guelph, Guelph, Ontario, Canada

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Highlights

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Endocannabinoids are involved in the regulation of nausea and vomiting.

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Controversy exists regarding the emetic/anti-emetic effects of 2-AG

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In the house musk shrew, 2AG does not produce vomiting and it is anti-emetic

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Species differences exist regarding the anti-emetic/emetic effects of 2-AG.

 

Abstract

The role of the endocannabinoid system in vomiting has been previously studied using several animal species. These investigations have clearly demonstrated an anti-emetic role for the eCB, anandamide, in these animal models; however, research concerning the role of 2-arhachidonoylglycerol (2AG) has been less clear. The aim of the present study was to assess the effects of exogenous 2AG administration in the house musk shrew, Suncus murinus. In Experiment 1, shrews were injected with vehicle or 2AG (1, 2, 5, 10 mg/kg) 15 min prior to behavioral testing in which the frequency of vomiting episodes was observed. In Experiment 2, shrews were pre-treated with 2AG (2, 5 mg/kg) prior to being administered the emetic drug, lithium chloride (LiCl). It was found that 2AG alone did not induce emesis, but interfered with vomiting in response to LiCl administration. The anti-emetic effects of 2AG in Suncus murinus do not appear to be mediated by CB1receptors, as concomitant pretreatment with the CB1 receptor antagonist, SR141716, did not reverse the suppressive effects of 2AG. These results confirm that manipulations that increase levels of 2AG exert anti-emetic effects in the house musk shrew.

Keywords

  • Emesis;
  • Endocannabinoid;
  • 2-Arachidonoylglycerol;
  • Lithium chloride;
  • Shrew

Figures and tables from this article:

Full-size image (20 K)
Fig. 1. Mean (+ sem) frequency of vomiting (upper graph) and retching (lower graph) episodes among the shrews treated with various doses of 2AG or vehicle in Experiment 1. The numbers in parentheses indicate n/group that displayed emetic/retching behavior. There was no significant difference in vomiting among any of the treatment groups as compared to vehicle-treated shrews.
Full-size image (24 K)
Fig. 2. Mean (+ sem) frequency of vomiting (upper graph) and retching (lower graph) episodes among the various treatment groups in Experiment 2. All shrews were treated with 0.15 M lithium chloride (LiCl; 390 mg/kg). The numbers in parentheses indicate n/group that displayed emetic/retching behavior following LiCl administration. The asterisks (*p < .05, **p < .01, ***p < .001) denote a significant difference compared to vehicle-treated shrews. Both 2 m/kg and 5 mg/kg 2AG interfered with LiCl-induced vomiting and retching, which was not reversed by the CB1 antagonist, SR141716.
Corresponding author contact information
Corresponding author at: Department of Psychology, University of Guelph, Guelph, ON, Canada, N1G 2W1. Tel.: + 1 519 824 4120; fax: + 1 519 837 8629.

Copyright © 2013 Published by Elsevier Inc.

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