Wong KL |
------>authors3_c=None ------>paper_class1=1 ------>Impact_Factor=None ------>paper_class3=2 ------>paper_class2=1 ------>vol=70 ------>confirm_bywho=ncchang ------>insert_bywho=thcheng ------>Jurnal_Rank=None ------>authors4_c=None ------>comm_author= ------>patent_EDate=None ------>authors5_c=None ------>publish_day=None ------>paper_class2Letter=None ------>page2=112 ------>medlineContent= ------>unit=E0109 ------>insert_date=20040506 ------>iam=4 ------>update_date=None ------>author=??? ------>change_event=5 ------>ISSN=None ------>authors_c=None ------>score=500 ------>journal_name=Planta Medica ------>paper_name=Isosteviol as a potassium channel opener to lower intracellular calcium concentrations in cultured aortic smooth muscle cells. ------>confirm_date=20040507 ------>tch_id=092006 ------>pmid=14994186 ------>page1=108 ------>fullAbstract=Isosteviol is a derivative of stevioside, a constituent of Stevia rebaudiana, and is commonly used as a non-caloric sugar substitute in Japan and Brazil. The present study attempted to elucidate the role of potassium (K (+)) channels in the action of isosteviol on intracellular calcium concentrations ([Ca (2+)]i) in cultured vascular smooth muscle (A7r5) cells using the Ca (2+)-sensitive dye Fura-2 as an indicator. The increase of [Ca (2+)]i in A7r5 cells produced by vasopressin (1 micromol/L) or phenylephrine (1 micromol/L) was attenuated by isosteviol from 0.01 micromol/L to 10 micromol/L. The attenuation by isosteviol of the vasopressin- and phenylephrine-induced increase in [Ca (2+)]i was inhibited by glibenclamide, apamin and 4-aminopyridine but not by charybdotoxin. Furthermore, the inhibitory action of isosteviol on [Ca (2+)]i was blocked when A7r5 cells co-treated with glibenclamide and apamin in conjunction with 4-aminopyridine were present. Therefore, not only did the ATP-sensitive potassium (K (ATP)) channel affect the action of isosteviol on [Ca (2+)]i modulation in A7r5 cells, but also those on the small conductance calcium-activated potassium (SK (Ca)) channels and voltage-gated (Kv) channels. However, the blockers of large-conductance Ca (2+)-activated potassium channels failed to modify the inhibitory action of isosteviol on [Ca (2+)]i. The obtained results indicated that a decrease of [Ca (2+)]i in A7r5 cells by isosteviol is mainly mediated by the selective opening of K (ATP) channel or/and SK (Ca) channel. Alteration in the Kv channel also plays a critical role in the inhibitory action of isosteviol. ------>tmu_sno=None ------>sno=9054 ------>authors2=Yang HY ------>authors3=Chan P ------>authors4=Cheng TH ------>authors5=Liu JC ------>authors6=Hsu FL, Liu IM, Cheng YW, Cheng JT ------>authors6_c=None ------>authors=Wong KL ------>delete_flag=0 ------>SCI_JNo=None ------>authors2_c=None ------>publish_area=None ------>updateTitle=Isosteviol as a potassium channel opener to lower intracellular calcium concentrations in cultured aortic smooth muscle cells. ------>language=2 ------>check_flag=None ------>submit_date=None ------>country=None ------>no= ------>patent_SDate=None ------>update_bywho=None ------>publish_year=2004 ------>submit_flag=None ------>publish_month=None |