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Role of Ca2+-dependent potassium channels in in vitro anandamide-mediated mesenteric vasorelaxation in rats with biliary cirrhosis.
Liver Int 2007; 27(8):1045-55LI

Abstract

BACKGROUND/AIM

Anandamide can activate potassium (K(+)) channels to induce an endothelium-dependent vasorelaxation in normal rat mesenteric arteries. Cannabinoids contribute partly to the splanchnic vasodilation in cirrhosis. This study investigated the roles of vascular K(+) channels in anandamide-induced mesenteric vasorelaxation in isolated rat cirrhotic vessels.

METHODS

The effects of the pretreatment of AM251, a specific CB(1) receptor antagonist, were assessed on the vascular reactivity to phenylephrine (PE), potassium chloride (KCl), acetylcholine (ACh) and sodium nitroprusside (SNP). Additionally, cannabinoid (CB(1) and CB(2)) receptors' protein expression and the effects of different K(+) channel blockers on vascular reactivity to anandamide were also studied.

RESULTS

Cirrhotic mesenteric arteries showed an overexpression of CB(1) receptor associated with hyporeactivity to PE and KCl, and hyper-response to ACh, SNP and anandamide. Pretreatment with AM251 significantly improved the hyporeactivity to KCl and ameliorated the hyper-response to ACh in cirrhotic vessels. Increased relaxation response to anandamide was suppressed by combinations of vascular Ca(2+)-dependent K(+) channel blockers (including apamin+charybdotoxin+iberiotoxin or apamin+TRAM-34+iberiotoxin) (TRAM-34, 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole).

CONCLUSIONS

In cirrhotic mesenteric arteries, vascular CB(1) receptor and anandamide contribute to the in vitro hyporeactivity to KCl. In addition, hyper-response to ACh may probably act through the modulation of vascular Ca(2+)-dependent K(+) channels.

Authors+Show Affiliations

Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

17845532

Citation

Yang, Ying-Ying, et al. "Role of Ca2+-dependent Potassium Channels in in Vitro Anandamide-mediated Mesenteric Vasorelaxation in Rats With Biliary Cirrhosis." Liver International : Official Journal of the International Association for the Study of the Liver, vol. 27, no. 8, 2007, pp. 1045-55.
Yang YY, Lin HC, Huang YT, et al. Role of Ca2+-dependent potassium channels in in vitro anandamide-mediated mesenteric vasorelaxation in rats with biliary cirrhosis. Liver Int. 2007;27(8):1045-55.
Yang, Y. Y., Lin, H. C., Huang, Y. T., Lee, T. Y., Hou, M. C., Wang, Y. W., ... Lee, S. D. (2007). Role of Ca2+-dependent potassium channels in in vitro anandamide-mediated mesenteric vasorelaxation in rats with biliary cirrhosis. Liver International : Official Journal of the International Association for the Study of the Liver, 27(8), pp. 1045-55.
Yang YY, et al. Role of Ca2+-dependent Potassium Channels in in Vitro Anandamide-mediated Mesenteric Vasorelaxation in Rats With Biliary Cirrhosis. Liver Int. 2007;27(8):1045-55. PubMed PMID: 17845532.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Role of Ca2+-dependent potassium channels in in vitro anandamide-mediated mesenteric vasorelaxation in rats with biliary cirrhosis. AU - Yang,Ying-Ying, AU - Lin,Han-Chieh, AU - Huang,Yi-Tsau, AU - Lee,Tzung-Yan, AU - Hou,Ming-Chih, AU - Wang,Ying-Wen, AU - Lee,Fa-Yauh, AU - Lee,Shou-Dong, PY - 2007/9/12/pubmed PY - 2007/12/21/medline PY - 2007/9/12/entrez SP - 1045 EP - 55 JF - Liver international : official journal of the International Association for the Study of the Liver JO - Liver Int. VL - 27 IS - 8 N2 - BACKGROUND/AIM: Anandamide can activate potassium (K(+)) channels to induce an endothelium-dependent vasorelaxation in normal rat mesenteric arteries. Cannabinoids contribute partly to the splanchnic vasodilation in cirrhosis. This study investigated the roles of vascular K(+) channels in anandamide-induced mesenteric vasorelaxation in isolated rat cirrhotic vessels. METHODS: The effects of the pretreatment of AM251, a specific CB(1) receptor antagonist, were assessed on the vascular reactivity to phenylephrine (PE), potassium chloride (KCl), acetylcholine (ACh) and sodium nitroprusside (SNP). Additionally, cannabinoid (CB(1) and CB(2)) receptors' protein expression and the effects of different K(+) channel blockers on vascular reactivity to anandamide were also studied. RESULTS: Cirrhotic mesenteric arteries showed an overexpression of CB(1) receptor associated with hyporeactivity to PE and KCl, and hyper-response to ACh, SNP and anandamide. Pretreatment with AM251 significantly improved the hyporeactivity to KCl and ameliorated the hyper-response to ACh in cirrhotic vessels. Increased relaxation response to anandamide was suppressed by combinations of vascular Ca(2+)-dependent K(+) channel blockers (including apamin+charybdotoxin+iberiotoxin or apamin+TRAM-34+iberiotoxin) (TRAM-34, 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole). CONCLUSIONS: In cirrhotic mesenteric arteries, vascular CB(1) receptor and anandamide contribute to the in vitro hyporeactivity to KCl. In addition, hyper-response to ACh may probably act through the modulation of vascular Ca(2+)-dependent K(+) channels. SN - 1478-3223 UR - https://www.unboundmedicine.com/medline/citation/17845532/Role_of_Ca2+_dependent_potassium_channels_in_in_vitro_anandamide_mediated_mesenteric_vasorelaxation_in_rats_with_biliary_cirrhosis_ L2 - https://doi.org/10.1111/j.1478-3231.2007.01551.x DB - PRIME DP - Unbound Medicine ER -