Title: Functional Characterization of Nonadrenergic Noncholinergic Neurotransmitter Release via Endocannabinoids: An in Vitro Study in Rabbit Corpus Cavernosum
Abstract: ABSTRACT Introduction Corporal smooth muscle relaxation is mediated mainly but not completely by nitric oxide. Endocannabinoids modulate the various neurotransmitter systems. Aim In the present study, a possible role of endocannabinoids on non-nitrergic nonadrenergic noncholinergic (NANC)-mediated relaxations was investigated. Methods In precontracted tissues, control electrical field stimulation (EFS)-induced NANC relaxation responses were obtained using varying frequencies of stimulation in the presence of L-arginine methyl ester (L-NAME), guanethidine, and atropine. To investigate the effects of cannabinoids on EFS-evoked non-nitrergic NANC relaxation responses, a similar experimental procedure was applied in the presence of cannabinoid receptor antagonists AM251 or AM630; vanilloid receptor antagonist capsazepine; or cannabinoid receptor agonists anandamide, arachidonyl-2-chloroethylamide (ACEA), or JHW015. Main Outcome Measures Effects of cannabinoid receptor antagonists and agonists on EFS-evoked non-nitrergic NANC relaxation responses. Results L-NAME abolished EFS-induced relaxation responses at lower frequencies (2–4 Hz) and inhibited the relaxation responses at higher frequencies (8–32 Hz). AM251 and AM630 either together or separately inhibited, whereas anandamide, ACEA, and JHW015 enhanced non-nitrergic NANC relaxation responses. Anandamide did not alter EFS-induced non-nitrergic NANC relaxations in the presence of AM251 and AM630. Capsazepine enhanced non-nitrergic NANC relaxation responses. Conclusion These results suggest that non-nitrergic NANC relaxations may be mediated partially by cannabinoid-like neuronal factors acting at both cannabinoid CB1 and cannabinoid CB2 receptors.
Publication Year: 2009
Publication Date: 2009-03-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
Access and Citation
Cited By Count: 9
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot