[Effects of osthole on the isolated guinea-pig ileum and taeniae coli].
Effects of osthole (Ost) and verapamil (Ver) were investigated in the isolated guinea-pig ileum and taeniae coli. In the isolated guinea-pig ileum or taeniae coli, Ost and Ver were both found to inhibit the contractions induced by acetylcholine (ACh), histamine (His) and KCl in a dose-dependent manner; and noncompetitively antagonize the CaCl2 cumulative dose-response curves, with pD2 values of 4.41 +/- 0.15 and 7.0 +/- 0.2, respectively. Ost at dose of 100 mumol/L and Ver at 1 mumol/L inhibited CaCl2 0.2 mmol/L induced the contractions of the isolated guinea-pig taeniae coli, and the contractions can be abolished by adding CaCl2 2 mmol/L in Ca(2+)-free medium; both of them showed pronounced inhibitions on intracellular calcium-dependent contractions induced by ACh, but showing no effects on the extracellular calcium-dependent contractions. These results indicate that Ost has calcium antagonistic effect and is similar to Ver in mechanism.
Institute of Clinical Pharmacology, Xian Medical University.
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Li
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Zhuang
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Zhao
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Zhao
D000109:Acetylcholine / Q000037:antagonists & inhibitors; D000818:Animals; D002118:Calcium / Q000037:antagonists & inhibitors; D003106:Colon / Q000187:drug effects; D003374:Coumarins / Q000494:pharmacology*; D005260:Female; D006168:Guinea Pigs; D006633:Histamine Antagonists / Q000494:pharmacology; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D014700:Verapamil / Q000494:pharmacology
D003374:Coumarins; D006633:Histamine Antagonists; D014700:Verapamil; D000109:Acetylcholine; D002118:Calcium; C046627:osthol