Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Mediation by 5‐hydroxytryptamine 2B receptors of endothelium‐dependent relaxation in rat jugular vein

Mediation by 5‐hydroxytryptamine 2B receptors of endothelium‐dependent relaxation in rat jugular... 1 An ‘atypical’ 5‐HT2 receptor which is located on the endothelium of rat jugular vein has been described. In the present study we have further defined the nature of the 5‐HT2 receptor subtype present in this preparation. 2 In experiments conducted in the presence of ketanserin to preclude involvement of 5‐HT2 receptors, the mixed 5‐HT2B/2C antagonist, SB 200646, acted as an antagonist of 5‐HT at the endothelial 5‐HT receptor (pA2 = 7.2). Yohimbine, which exhibits negligible affinity for rat 5‐HT2C receptors but has high 5‐HT2B receptor affinity, acted as a potent but non‐surmountable antagonist (pA2 ≥ 7.3) in rat jugular vein. Neither yohimbine nor SB 200646 affected endothelium‐dependent relaxations induced by carbachol. 3 Mianserin also acted as a surmountable antagonist (pA2 = 7.3) and the 5‐HT2B agonist, BW 723C86, acted as a potent partial agonist (pEC50 (95% C L), intrinsic activity ± s.e.mean = 7.9 (7.6–8.3), 0.84 ± 0.04). Responses to BW 723C86 were antagonized by SB 200646 (0.3 μm) yielding an ‘apparent’ pA2 (95% CL) of 7.03 (6.76–7.32). 4 These data are consistent with the presence of 5‐HT2B receptors mediating endothelium‐dependent relaxation of rat jugular vein. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png British Journal of Pharmacology Wiley

Mediation by 5‐hydroxytryptamine 2B receptors of endothelium‐dependent relaxation in rat jugular vein

Download PDF
5 pages

Loading next page...
 
/lp/wiley/mediation-by-5-hydroxytryptamine-2b-receptors-of-endothelium-dependent-0Km5i5muUt

References (19)

Publisher
Wiley
Copyright
1995 British Pharmacological Society
ISSN
0007-1188
eISSN
1476-5381
DOI
10.1111/j.1476-5381.1995.tb13240.x
Publisher site
See Article on Publisher Site

Abstract

1 An ‘atypical’ 5‐HT2 receptor which is located on the endothelium of rat jugular vein has been described. In the present study we have further defined the nature of the 5‐HT2 receptor subtype present in this preparation. 2 In experiments conducted in the presence of ketanserin to preclude involvement of 5‐HT2 receptors, the mixed 5‐HT2B/2C antagonist, SB 200646, acted as an antagonist of 5‐HT at the endothelial 5‐HT receptor (pA2 = 7.2). Yohimbine, which exhibits negligible affinity for rat 5‐HT2C receptors but has high 5‐HT2B receptor affinity, acted as a potent but non‐surmountable antagonist (pA2 ≥ 7.3) in rat jugular vein. Neither yohimbine nor SB 200646 affected endothelium‐dependent relaxations induced by carbachol. 3 Mianserin also acted as a surmountable antagonist (pA2 = 7.3) and the 5‐HT2B agonist, BW 723C86, acted as a potent partial agonist (pEC50 (95% C L), intrinsic activity ± s.e.mean = 7.9 (7.6–8.3), 0.84 ± 0.04). Responses to BW 723C86 were antagonized by SB 200646 (0.3 μm) yielding an ‘apparent’ pA2 (95% CL) of 7.03 (6.76–7.32). 4 These data are consistent with the presence of 5‐HT2B receptors mediating endothelium‐dependent relaxation of rat jugular vein.

Journal

British Journal of Pharmacology – Wiley

Published: Jan 1, 1995

There are no references for this article.