[Vasorelaxant effects of forsythiaside from the fruits of Forsythia suspensa].
The vasorelaxant effects of forsythiaside (compound 1) from the fruits of Forsythia suspensa on isolated rat aortic rings were studied. Compound 1 showed a slow relaxation activity against norepinephrine (NE)-induced contractions of rat aorta with/without endothelium. This compound did not affect contractions induced by a high concentration of potassium (K(+) 60 mM), while it inhibited NE-induced vasocontraction in the presence of nicardipine. These results show that the inhibition by compound 1 of NE-induced vasocontraction is due to a decrease in calcium influx from the extracellular space caused by NE.
Iizuka
Toru
T
The Faculty of Pharmaceutical Sciences, Hoshi University, Tokyo 142-8501, Japan. iizuka@hoshi.ac.jp
Nagai
Masahiro
M
D000818:Animals; D001011:Aorta / Q000187:drug effects; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005110:Extracellular Space / Q000378:metabolism; D031657:Forsythia / Q000737:chemistry*; D006027:Glycosides / Q000302:isolation & purification / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009529:Nicardipine / Q000494:pharmacology; D009638:Norepinephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D015220:Calcium Channels; D006027:Glycosides; D009529:Nicardipine; C058049:forsythiaside; D011188:Potassium; D002118:Calcium; D009638:Norepinephrine