Analysis of the Vasorelaxant Action of Angiotensin II in the Isolated Rat Renal Artery
Taking into consideration that mechanisms involved in the vasodilatator actions of angiotensin II have not yet been completely elucidated, the present study was undertaken in order to examine the mechanisms underlying the angiotensin II–induced relaxation of rat renal artery (RRA). Angiotensin II pr...
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| Format: | Article |
| Language: | English |
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Elsevier
2008-01-01
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| Series: | Journal of Pharmacological Sciences |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1347861319314963 |
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| author | Leposava Grbović Jelena Djokić Miroslav Radenković Srðan Pešic |
| author_facet | Leposava Grbović Jelena Djokić Miroslav Radenković Srðan Pešic |
| author_sort | Leposava Grbović |
| collection | DOAJ |
| description | Taking into consideration that mechanisms involved in the vasodilatator actions of angiotensin II have not yet been completely elucidated, the present study was undertaken in order to examine the mechanisms underlying the angiotensin II–induced relaxation of rat renal artery (RRA). Angiotensin II produced concentration-dependent and endothelium-independent relaxation of isolated RRA. Angiotensin II–induced relaxation was partially reduced by inhibitors of nitric oxide synthase and guanylyl cyclase. The remaining dilatation was inhibited by a potassium channel blocker, charybdotoxin. Precontraction of RRA with high concentration of K+partially reduced angiotensin II–evoked relaxation, while indomethacin, glibenclamide, apamin and barium did not alter the angiotensin II concentration-response curve. Losartan had no effect on angiotensin II effect. Oppositely, HOE 140 and PD123319, separately or in combination, partially antagonized vasorelaxation induced by angiotensin II. Complete blockade of RRA response was obtained after simultaneous incubation of all three receptor antagonists HOE-140, PD123319, and losartan; L-NOARG plus HOE-140; or PD123319 plus charybdotoxin. These results indicate that angiotensin II produces endothelium-independent relaxation of RRA, which is most probably mediated by the interaction of the NO-cGMP pathway and K+channels. Moreover, we can assume that AT1, AT2, and B2receptors are involved in the vasorelaxant effect of angiotensin II. Keywords:: angiotensin II, rat renal artery, vasorelaxation, K+channel, AT receptor |
| first_indexed | 2024-04-13T03:33:10Z |
| format | Article |
| id | doaj.art-d8f2f4c45e7d4de5a61a8f5a0975d245 |
| institution | Directory Open Access Journal |
| issn | 1347-8613 |
| language | English |
| last_indexed | 2024-04-13T03:33:10Z |
| publishDate | 2008-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Pharmacological Sciences |
| spelling | doaj.art-d8f2f4c45e7d4de5a61a8f5a0975d2452022-12-22T03:04:25ZengElsevierJournal of Pharmacological Sciences1347-86132008-01-011063376384Analysis of the Vasorelaxant Action of Angiotensin II in the Isolated Rat Renal ArteryLeposava Grbović0Jelena Djokić1Miroslav Radenković2Srðan Pešic3Department of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade 11129, SerbiaDepartment of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade 11129, Serbia; Corresponding author. jelenadjokic2003@yahoo.co.ukDepartment of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Belgrade, Belgrade 11129, SerbiaDepartment of Pharmacology, Faculty of Medicine, University of Niš, Niš 18000, SerbiaTaking into consideration that mechanisms involved in the vasodilatator actions of angiotensin II have not yet been completely elucidated, the present study was undertaken in order to examine the mechanisms underlying the angiotensin II–induced relaxation of rat renal artery (RRA). Angiotensin II produced concentration-dependent and endothelium-independent relaxation of isolated RRA. Angiotensin II–induced relaxation was partially reduced by inhibitors of nitric oxide synthase and guanylyl cyclase. The remaining dilatation was inhibited by a potassium channel blocker, charybdotoxin. Precontraction of RRA with high concentration of K+partially reduced angiotensin II–evoked relaxation, while indomethacin, glibenclamide, apamin and barium did not alter the angiotensin II concentration-response curve. Losartan had no effect on angiotensin II effect. Oppositely, HOE 140 and PD123319, separately or in combination, partially antagonized vasorelaxation induced by angiotensin II. Complete blockade of RRA response was obtained after simultaneous incubation of all three receptor antagonists HOE-140, PD123319, and losartan; L-NOARG plus HOE-140; or PD123319 plus charybdotoxin. These results indicate that angiotensin II produces endothelium-independent relaxation of RRA, which is most probably mediated by the interaction of the NO-cGMP pathway and K+channels. Moreover, we can assume that AT1, AT2, and B2receptors are involved in the vasorelaxant effect of angiotensin II. Keywords:: angiotensin II, rat renal artery, vasorelaxation, K+channel, AT receptorhttp://www.sciencedirect.com/science/article/pii/S1347861319314963 |
| spellingShingle | Leposava Grbović Jelena Djokić Miroslav Radenković Srðan Pešic Analysis of the Vasorelaxant Action of Angiotensin II in the Isolated Rat Renal Artery Journal of Pharmacological Sciences |
| title | Analysis of the Vasorelaxant Action of Angiotensin II in the Isolated Rat Renal Artery |
| title_full | Analysis of the Vasorelaxant Action of Angiotensin II in the Isolated Rat Renal Artery |
| title_fullStr | Analysis of the Vasorelaxant Action of Angiotensin II in the Isolated Rat Renal Artery |
| title_full_unstemmed | Analysis of the Vasorelaxant Action of Angiotensin II in the Isolated Rat Renal Artery |
| title_short | Analysis of the Vasorelaxant Action of Angiotensin II in the Isolated Rat Renal Artery |
| title_sort | analysis of the vasorelaxant action of angiotensin ii in the isolated rat renal artery |
| url | http://www.sciencedirect.com/science/article/pii/S1347861319314963 |
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