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The effects of Delta9-tetrahydrocannabinol in rat mesenteric vasculature, and its interactions with the endocannabinoid anandamide.
Br J Pharmacol. 2005 Jun; 145(4):514-26.BJ

Abstract

1 Delta9-tetrahydrocannabinol (THC) produces varying effects in mesenteric arteries: vasorelaxation (third-order branches, G3), modest vasorelaxation (G2), no effect (G1) and vasoconstriction (the superior mesenteric artery, G0). 2 In G3, vasorelaxation to THC was inhibited by pertussis toxin, but was unaffected by the CB1 receptor antagonist, AM251 (1 microM), incubation with the TRPV1 receptor agonist capsaicin (10 microM, 1 h), the TRPV1 receptor antagonist capsazepine (10 microM) or de-endothelialisation. 3 In G3, vasorelaxation to THC was inhibited by high K+ buffer, and by the following K+ channel inhibitors: charybdotoxin (100 nM), apamin (500 nM) and barium chloride (30 microM), but not by 4-aminopyridine, glibenclamide or tertiapin. 4 In G3, THC (10 and 100 microM) inhibited the contractile response to Ca2+ in a Ca2+-free, high potassium buffer, indicating that THC blocks Ca2+ influx. 5 In G0, the vasoconstrictor responses to THC were inhibited by de-endothelialisation and SR141716A (100 nM), but not by the endothelin (ET(A)) receptor antagonist FR139317 (1 microM).THC (1 and 10 microM) antagonised vasorelaxation to anandamide in G3 but not G0. THC did not antagonise the noncannabinoid verapamil, capsaicin or the CB1 receptor agonist CP55,940. 6 THC (10 and 100 microM) inhibited endothelium-derived relaxing factor (EDHF)-mediated responses to carbachol in a manner similar to the gap junction inhibitor 18alpha-glycyrrhetinic acid. 7 These data show that THC causes vasorelaxation through activation of K+ channels and inhibition of Ca2+ channels, and this involves non-CB1, non-TRPV1 but G-protein-coupled receptors. In G0, THC does not cause relaxation and at high concentrations causes contractions. Importantly, THC antagonises the effects of anandamide, possibly through inhibition of EDHF activity.

Authors+Show Affiliations

School of Biomedical Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH. saoirse.o'sullivan@nottingham.ac.ukNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15821751

Citation

O'Sullivan, Saoirse E., et al. "The Effects of Delta9-tetrahydrocannabinol in Rat Mesenteric Vasculature, and Its Interactions With the Endocannabinoid Anandamide." British Journal of Pharmacology, vol. 145, no. 4, 2005, pp. 514-26.
O'Sullivan SE, Kendall DA, Randall MD. The effects of Delta9-tetrahydrocannabinol in rat mesenteric vasculature, and its interactions with the endocannabinoid anandamide. Br J Pharmacol. 2005;145(4):514-26.
O'Sullivan, S. E., Kendall, D. A., & Randall, M. D. (2005). The effects of Delta9-tetrahydrocannabinol in rat mesenteric vasculature, and its interactions with the endocannabinoid anandamide. British Journal of Pharmacology, 145(4), 514-26.
O'Sullivan SE, Kendall DA, Randall MD. The Effects of Delta9-tetrahydrocannabinol in Rat Mesenteric Vasculature, and Its Interactions With the Endocannabinoid Anandamide. Br J Pharmacol. 2005;145(4):514-26. PubMed PMID: 15821751.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The effects of Delta9-tetrahydrocannabinol in rat mesenteric vasculature, and its interactions with the endocannabinoid anandamide. AU - O'Sullivan,Saoirse E, AU - Kendall,David A, AU - Randall,Michael D, PY - 2005/4/12/pubmed PY - 2005/8/30/medline PY - 2005/4/12/entrez SP - 514 EP - 26 JF - British journal of pharmacology JO - Br J Pharmacol VL - 145 IS - 4 N2 - 1 Delta9-tetrahydrocannabinol (THC) produces varying effects in mesenteric arteries: vasorelaxation (third-order branches, G3), modest vasorelaxation (G2), no effect (G1) and vasoconstriction (the superior mesenteric artery, G0). 2 In G3, vasorelaxation to THC was inhibited by pertussis toxin, but was unaffected by the CB1 receptor antagonist, AM251 (1 microM), incubation with the TRPV1 receptor agonist capsaicin (10 microM, 1 h), the TRPV1 receptor antagonist capsazepine (10 microM) or de-endothelialisation. 3 In G3, vasorelaxation to THC was inhibited by high K+ buffer, and by the following K+ channel inhibitors: charybdotoxin (100 nM), apamin (500 nM) and barium chloride (30 microM), but not by 4-aminopyridine, glibenclamide or tertiapin. 4 In G3, THC (10 and 100 microM) inhibited the contractile response to Ca2+ in a Ca2+-free, high potassium buffer, indicating that THC blocks Ca2+ influx. 5 In G0, the vasoconstrictor responses to THC were inhibited by de-endothelialisation and SR141716A (100 nM), but not by the endothelin (ET(A)) receptor antagonist FR139317 (1 microM).THC (1 and 10 microM) antagonised vasorelaxation to anandamide in G3 but not G0. THC did not antagonise the noncannabinoid verapamil, capsaicin or the CB1 receptor agonist CP55,940. 6 THC (10 and 100 microM) inhibited endothelium-derived relaxing factor (EDHF)-mediated responses to carbachol in a manner similar to the gap junction inhibitor 18alpha-glycyrrhetinic acid. 7 These data show that THC causes vasorelaxation through activation of K+ channels and inhibition of Ca2+ channels, and this involves non-CB1, non-TRPV1 but G-protein-coupled receptors. In G0, THC does not cause relaxation and at high concentrations causes contractions. Importantly, THC antagonises the effects of anandamide, possibly through inhibition of EDHF activity. SN - 0007-1188 UR - https://www.unboundmedicine.com/medline/citation/15821751/The_effects_of_Delta9_tetrahydrocannabinol_in_rat_mesenteric_vasculature_and_its_interactions_with_the_endocannabinoid_anandamide_ L2 - https://doi.org/10.1038/sj.bjp.0706218 DB - PRIME DP - Unbound Medicine ER -