Distribution and Function of Cannabinoid Receptors 1 and 2 in the Rat, Monkey and Human Bladder
Författare
Summary, in English
Purpose: We investigated the distribution of cannabinoid receptor subtypes 1 and 2 in the detrusor of different species and studied the effects of cannabinoid receptor 1 and 2 agonists on bladder function. Materials and Methods: Cannabinoid receptor 1 and 2 expression was studied with Western blot and immunohistochemistry in rat, monkey and human detrusors. Co-staining was done for markers of sensory nerves using calcitonin gene-related peptide (Euro-Diagnostica, Malmo, Sweden) and transient receptor potential vanilloid 1, and for cholinergic nerves using VAChT (Santa Cruz Biotechnology, Santa Cruz, California). Actions of the endogenous cannabinoid receptor-1 and 2 agonist anandamide (Sigma (R)), and the cannabinoid receptor 1 and 2 agonist CP55,940 (Sigma) on isolated detrusor and during cystometry in conscious rats were recorded. Results: Higher expression of cannabinoid receptor 2 but not cannabinoid receptor 1 was noted in the mucosa than in the detrusor. Compared to the detrusor larger amounts of cannabinoid receptor 2 containing nerves that also expressed transient receptor potential vanilloid 1 or calcitonin gene-related peptide were observed in the suburothelium. Nerve fibers containing cannabinoid receptor 2 and VAChT were located in the detrusor. Neither anandamide nor CP55,940 affected isolated detrusor carbachol (Sigma) contractions. Nerve contractions were enhanced by 10 mu M anandamide and decreased by 10 AM CP55,940 (P<0.05). In vivo CP55,940 increased the micturition interval by 46% and threshold pressure by 124% (p <0.05). Anandamide increased threshold pressure by 26% and decreased the micturition interval by 19% (p <0.05 and <0.01, respectively). Conclusions: The distribution of cannabinoid receptor 2 on sensory nerves and in the urothelium, and effects by CP55940 on the micturition interval and threshold pressure suggest a role for cannabinoid receptor 2 in bladder afferent signals. Co-expression of VAChT and cannabinoid receptor 2, and effects by CP55940 on nerve contractions suggest a cannabinoid receptor 2 mediated modulatory effect on cholinergic nerve activity. Anandamide may not be a good tool for cannabinoid receptor studies due to its activity at other receptors.
Avdelning/ar
Publiceringsår
2009
Språk
Engelska
Sidor
1939-1948
Publikation/Tidskrift/Serie
Journal of Urology
Volym
181
Issue
4
Dokumenttyp
Artikel i tidskrift
Förlag
Lippincott Williams & Wilkins
Ämne
- Urology and Nephrology
Nyckelord
- multiple sclerosis
- anandamide
- bladder
- cannabinoid
- receptors
- urination
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1527-3792