Biomaterial Database

Relaxation of large coronary artery by verapamil, D600, and nifedipine is constrictor selective: comparison with glyceryl trinitrate. 1983

J A Angus, and R M Brazenor

We compared the vasodilator potencies of a number of Ca2+-entry blockers with glyceryl trinitrate (GTN) in isolated ring segments of dog coronary arteries contracted by a variety of substances. Rings were contracted to 80% of maximum by serotonin, phenylephrine (PE), noradrenaline (NA), K+ (KCl), or U46619 (stable thromboxane A2 analogue). Cumulative additions of a vasodilator then relaxed the ring towards basal tone. GTN had a similar IC50 value (0.1 - 0.3 microM) regardless of the substance used to contract the ring. In contrast, nifedipine and verapamil were weak relaxant drugs against arteries contracted by U46619. Nifedipine was most potent in rings contracted by K+, whereas verapamil was similarly effective towards K+ and serotonin, but threefold less potent against PE or NA. The (-)enantiomers of verapamil and D600 were more potent (seven-to 26-fold) than the (+)enantiomers in arteries contracted by K+ or serotonin, but not for PE or NA. A combination of (-)verapamil and GTN showed additive effects without a change in the IC50 for GTN. We conclude that, in contrast with GTN, the effectiveness of Ca2+-entry blockers in the treatment of coronary vasospasm may be dependent on the nature of the constrictor signal.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009543	Nifedipine	A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.	Adalat,BAY-a-1040,Bay-1040,Cordipin,Cordipine,Corinfar,Fenigidin,Korinfar,Nifangin,Nifedipine Monohydrochloride,Nifedipine-GTIS,Procardia,Procardia XL,Vascard,BAY a 1040,BAYa1040,Bay 1040,Bay1040,Monohydrochloride, Nifedipine,Nifedipine GTIS
D010656	Phenylephrine	An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent.	(R)-3-Hydroxy-alpha-((methylamino)methyl)benzenemethanol,Metaoxedrin,Metasympatol,Mezaton,Neo-Synephrine,Neosynephrine,Phenylephrine Hydrochloride,Phenylephrine Tannate,Neo Synephrine,Tannate, Phenylephrine
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D011450	Prostaglandin Endoperoxides, Synthetic	Synthetic compounds that are analogs of the naturally occurring prostaglandin endoperoxides and that mimic their pharmacologic and physiologic activities. They are usually more stable than the naturally occurring compounds.	Prostaglandin Endoperoxide Analogs,Prostaglandin Endoperoxide Analogues,Synthetic Prostaglandin Endoperoxides,Analogues, Prostaglandin Endoperoxide,Endoperoxide Analogues, Prostaglandin,Endoperoxides, Synthetic Prostaglandin
D011725	Pyridines	Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.
D003331	Coronary Vessels	The veins and arteries of the HEART.	Coronary Arteries,Sinus Node Artery,Coronary Veins,Arteries, Coronary,Arteries, Sinus Node,Artery, Coronary,Artery, Sinus Node,Coronary Artery,Coronary Vein,Coronary Vessel,Sinus Node Arteries,Vein, Coronary,Veins, Coronary,Vessel, Coronary,Vessels, Coronary
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D005260	Female		Females
D005711	Gallopamil	Coronary vasodilator that is an analog of iproveratril (VERAPAMIL) with one more methoxy group on the benzene ring.	Methoxyverapamil,D-600,D600,Elgiprona,Gallobeta,Gallopamil Hydrochloride,Prebet,Procorum,gallopamil von ct,D 600,Hydrochloride, Gallopamil