Responses of human, monkey and dog coronary arteries in vitro to carbocyclic thromboxane A2 and vasodilators. 1984

N Toda

Carbocyclic thromboxane A2 (cTxA2), a stable analogue of TxA2, and prostaglandin (PG) F2 alpha contracted helical strips of human, monkey and dog coronary arteries in a concentration-dependent manner. Apparent ED50 values for cTxA2 were markedly less (1/58 in humans, 1/373 in monkeys and 1/397 in dogs) than those for PGF2 alpha; maximum contractions induced by cTxA2 and PGF2 alpha relative to those induced by 30 mM K+ were approximately identical in the human and monkey arteries. PGI2 caused a concentration-related relaxation in human and dog coronary arteries maximally precontracted with cTxA2 and in human, monkey and dog coronary arteries partially precontracted with PGF2 alpha. The relaxation response was greatest in the dog arteries and least in the monkey arteries. Contractions induced by cTxA2 or PGF2 alpha and relaxations induced by PGI2 were selectively antagonized by treatment with diphloretin phosphate. Human coronary artery strips contracted with cTxA2 responded to nitroglycerine with a rapid, transient relaxation and to verapamil with a slowly-developing, persistent relaxation, as did monkey and dog coronary artery strips. Thromboxane (Tx) A2 appears to be one of the most potent endogenous vasoconstrictors in human coronary arteries, if cTxA2 acts on TxA2 receptors. It is suggested that PGI2, nitroglycerine and verapamil are effective vasodilators in human conduit coronary arteries maximally contracted with cTxA2, although the extent and the duration of vasodilatation induced by these agents were quite different.

UI MeSH Term Description Entries
D008251 Macaca A genus of the subfamily CERCOPITHECINAE, family CERCOPITHECIDAE, consisting of 16 species inhabiting forests of Africa, Asia, and the islands of Borneo, Philippines, and Celebes. Ape, Barbary,Ape, Black,Ape, Celebes,Barbary Ape,Black Ape,Celebes Ape,Macaque,Apes, Barbary,Apes, Black,Apes, Celebes,Barbary Apes,Black Apes,Celebes Apes,Macacas,Macaques
D008297 Male Males
D008875 Middle Aged An adult aged 45 - 64 years. Middle Age
D009126 Muscle Relaxation That phase of a muscle twitch during which a muscle returns to a resting position. Muscle Relaxations,Relaxation, Muscle,Relaxations, Muscle
D009131 Muscle, Smooth, Vascular The nonstriated involuntary muscle tissue of blood vessels. Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
D011121 Polyphloretin Phosphate A polymeric mixture of polyesters of phosphoric acid and phloretin. It blocks some cellular responses to prostaglandins. Phosphate, Polyphloretin
D011460 Prostaglandins F (9 alpha,11 alpha,13E,15S)-9,11,15-Trihydroxyprost-13-en-1-oic acid (PGF(1 alpha)); (5Z,9 alpha,11,alpha,13E,15S)-9,11,15-trihydroxyprosta-5,13-dien-1-oic acid (PGF(2 alpha)); (5Z,9 alpha,11 alpha,13E,15S,17Z)-9,11,15-trihydroxyprosta-5,13,17-trien-1-oic acid (PGF(3 alpha)). A family of prostaglandins that includes three of the six naturally occurring prostaglandins. All naturally occurring PGF have an alpha configuration at the 9-carbon position. They stimulate uterine and bronchial smooth muscle and are often used as oxytocics. PGF
D011464 Epoprostenol A prostaglandin that is a powerful vasodilator and inhibits platelet aggregation. It is biosynthesized enzymatically from PROSTAGLANDIN ENDOPEROXIDES in human vascular tissue. The sodium salt has been also used to treat primary pulmonary hypertension (HYPERTENSION, PULMONARY). Prostacyclin,Prostaglandin I2,Epoprostanol,Epoprostenol Sodium,Epoprostenol Sodium Salt, (5Z,9alpha,11alpha,13E,15S)-Isomer,Flolan,Prostaglandin I(2),Veletri
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

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