Alpha-adrenoceptor blocking action of aaptamine, a novel marine natural product, in vascular smooth muscle.
In the rabbit isolated aorta and renal artery, aaptamine (3 X 10(-5)M), a novel heteroaromatic substance isolated from a sea sponge Aaptos aaptos produced a parallel, rightward shift of the dose-response curve for noradrenaline, whereas that for histamine or KCl was not affected. But, the derivatives of aaptamine, demethylaaptamine, demethyloxyaaptamine, dihydroaaptamine and dihydrodemethylaaptamine at concentrations of 10(-5) to 10(-4)M had no effect on the dose-response curve for noradrenaline. These results suggest that aaptamine is a competitive antagonist of alpha-adrenoceptors in vascular smooth muscles.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009287:Naphthyridines / Q000494:pharmacology*; D009638:Norepinephrine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D011817:Rabbits; D012077:Renal Artery / Q000187:drug effects
D000317:Adrenergic alpha-Antagonists; D009287:Naphthyridines; D011189:Potassium Chloride; D006632:Histamine; C043986:aaptamine; D009638:Norepinephrine