Endothelium-derived factors and k+ channels are involved in the vasorelaxation induced by Sida cordifolia L. in the rat superior mesenteric artery
| Autor: | M R V, Santos, N M S, Nascimento, A R, Antoniolli, I A, Medeiros |
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| Rok vydání: | 2006 |
| Předmět: |
Potassium Channels
Charybdotoxin Nitric Oxide Synthase Type III Plant Extracts Muscle Relaxation Anti-Inflammatory Agents Non-Steroidal Indomethacin In Vitro Techniques Muscle Smooth Vascular Potassium Chloride Rats Plant Leaves NG-Nitroarginine Methyl Ester Mesenteric Artery Superior Animals Endothelium Vascular Enzyme Inhibitors Malvaceae |
| Zdroj: | Die Pharmazie. 61(5) |
| ISSN: | 0031-7144 |
| Popis: | The vasorelaxantion of the aqueous fraction of the hydroalcoholic extract of the Sida cordifolia leaves (AFSC) was evaluated in this work. In rat superior mesenteric artery, AFSC (3-1000 microg/mL) induced relaxation of phenylephrine-induced contractions. This effect was significantly attenuated after removal of the endothelium, after atropine (1 microM), L-NAME (100 microM), indomethacin (10 microM), high K+ (20 mM), tetraethylammonium (1 microM), a K(Ca) blocker, apamin (1 microM), a SK(Ca) blocker and ChTX (0.1 microM), a BK(Ca) blocker, however, it was not affected after glibenclamide (10 microM), an KATP blocker, and 4-aminopyridine (1 microM), a Kv blocker. ChTX (0.1 microM) was able to induce an additional inhibition of the vasorelaxation induced by AFSC in the presence of L-NAME plus indomethacin. The vasorelaxation induced by AFSC in the presence of L-NAME plus indomethacin plus ChTX was not different from that induced by AFSC in rings without endothelium. In conclusion, the results show that endothelium-derived factors (mainly NO, PGI2) and K+ channels (BK(Ca) and SK(Ca)) play a crucial role in the vasorelaxation induced by AFSC in the rat superior mesenteric artery. |
| Databáze: | OpenAIRE |
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