Skip Navigation


ToxSci Advance Access originally published online on August 27, 2003
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
76/1/131    most recent
kfg216v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (3)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Segall, Y.
Right arrow Articles by Casida, J. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Segall, Y.
Right arrow Articles by Casida, J. E.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Toxicological Sciences 76, 131-137 (2003)
Copyright © 2003 by the Society of Toxicology

NEUROTOXICOLOGY

Toxicological and Structural Features of Organophosphorus and Organosulfur Cannabinoid CB1 Receptor Ligands

Yoffi Segall1, Gary B. Quistad, Susan E. Sparks, Daniel K. Nomura and John E. Casida2

Environmental Chemistry and Toxicology Laboratory, Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720-3112

Potent cannabinoid CB1 receptor ligands include anandamide [N-(2-hydroxyethyl)arachidonamide], {Delta}9-tetrahydrocannabinol, and 3H-CP 55,940 at the agonist site and selected organophosphorus esters (including some pesticides) and organosulfur compounds at a proposed closely coupled "nucleophilic" site. This study considers the toxicological and structural features of alkylfluorophosphonates, benzodioxaphosphorin oxides, alkanesulfonyl fluorides, and analogs acting at the nucleophilic site. Binding at the agonist site, using3H-CP 55,940 in assays with mouse brain membranes, is inhibited byO-isopropyl dodecylfluorophosphonate (compound 2), dodecanesulfonyl fluoride (compound 14) and dodecylbenzodioxaphosphorin oxide with IC50 values of 2–11 nM. Compounds 2 and 14 are also effectivein vivo, with 84% inhibition of mouse brain CB1 binding 4 h after intraperitoneal dosage at 30 mg/kg. Compound 14-inhibited CB1 in mouse brain requires about 3–4 days for recovery of 50% activity, suggesting covalent derivatization. Delayed toxicity (mortality in 0.3–5 days) from compounds 2, 14, and octanesulfonyl fluoride (18) is more closely associated with in vivo inhibition of brain neuropathy target esterase–lysophospholipase (NTE-LysoPLA) than with that of CB1 or acetylcholinesterase. NTE-LysoPLA inhibited by sulfonyl fluorides 14 and 18 cannot "age," a proposed requirement for NTE phosphorylated by organophosphorus-delayed neurotoxicants. Several octane- and dodecanesulfonamides with N-(2-hydroxyethyl) and other substituents based on anandamide give depressed mobility and recumbent posture in mice, but the effects do not correlate with potency for CB1 inhibition in vitro. Specific toxicological responses are not clearly associated with organophosphorus- or organosulfur-induced inhibition of the proposed CB1 nucleophilic site in mouse brain. On the other hand, the most potent CB1 inhibitors examined here are also NTE-LysoPLA inhibitors and cause delayed toxicity in mice.

Key Words: cannabinoid receptor; CB1; dodecanesulfonyl fluoride; O-isopropyl dodecylfluorophosphonate; neuropathy target esterase; lysophospholipase; fatty acid amide hydrolase.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.