Biomaterial Database

Thromboxane A2 receptor antagonists inhibit endothelium-dependent contractions. 1990

W Auch-Schwelk, and Z S Katusic, and P M Vanhoutte

Department of Physiology and Biophysics, Mayo Clinic, Rochester, Minnesota.

Endothelium-dependent contractions to acetylcholine and endothelium-independent contractions to oxygen-derived free radicals in the aorta of the spontaneously hypertensive rat (SHR) are mediated by an unidentified product of the cyclooxygenase pathway of arachidonic acid metabolism. To determine the role of thromboxane A2 (TXA2) or prostaglandin H2 (PGH2) in these contractions, rings of the thoracic aorta of SHR were suspended in organ chambers for measurement of isometric force. Acetylcholine caused endothelium-dependent contractions in quiescent rings from SHR aortas. Oxygen-derived free radicals generated with xanthine plus xanthine oxidase caused contractions in rings without endothelium. Dazoxiben (thromboxane synthetase inhibitor) did not affect contractions evoked by acetylcholine. AH 23,848, SQ 29,548, or R 68,070 (TXA2/PGH2 receptor antagonists) inhibited contractions to U 46,619 (a TXA2/PGH2 receptor agonist), acetylcholine, and oxygen-derived free radicals. Acetylcholine stimulated the release of prostacyclin from Wistar-Kyoto (WKY) rat and SHR aortas but not the release of other prostaglandins (PGE2, PGF2 alpha, TXA2). Oxygen-derived free radicals did not stimulate the release of prostaglandins from either SHR or WKY rat aortas. These results demonstrate that stimulation of TXA2/PGH2 receptors probably by PGH2 might be involved in endothelium-dependent contractions. Oxygen-derived free radicals, which might be an endothelium-derived contracting factor or factors, ultimately cause contraction by stimulation of TXA2/PGH2 receptors.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
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
D011453	Prostaglandins	A group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase pathway. They are extremely potent mediators of a diverse group of physiological processes.	Prostaglandin,Prostanoid,Prostanoids
D011918	Rats, Inbred SHR	A strain of Rattus norvegicus with elevated blood pressure used as a model for studying hypertension and stroke.	Rats, Spontaneously Hypertensive,Rats, SHR,Inbred SHR Rat,Inbred SHR Rats,Rat, Inbred SHR,Rat, SHR,Rat, Spontaneously Hypertensive,SHR Rat,SHR Rat, Inbred,SHR Rats,SHR Rats, Inbred,Spontaneously Hypertensive Rat,Spontaneously Hypertensive Rats
D011921	Rats, Inbred WKY	A strain of Rattus norvegicus used as a normotensive control for the spontaneous hypertensive rats (SHR).	Rats, Wistar Kyoto,Wistar Kyoto Rat,Rats, WKY,Inbred WKY Rat,Inbred WKY Rats,Kyoto Rat, Wistar,Rat, Inbred WKY,Rat, WKY,Rat, Wistar Kyoto,WKY Rat,WKY Rat, Inbred,WKY Rats,WKY Rats, Inbred,Wistar Kyoto Rats
D011982	Receptors, Prostaglandin	Cell surface receptors that bind prostaglandins with high affinity and trigger intracellular changes which influence the behavior of cells. Prostaglandin receptor subtypes have been tentatively named according to their relative affinities for the endogenous prostaglandins. They include those which prefer prostaglandin D2 (DP receptors), prostaglandin E2 (EP1, EP2, and EP3 receptors), prostaglandin F2-alpha (FP receptors), and prostacyclin (IP receptors).	Prostaglandin Receptors,Prostaglandin Receptor,Receptor, Prostaglandin,Receptors, Prostaglandins,Prostaglandins Receptors
D004730	Endothelium, Vascular	Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.	Capillary Endothelium,Vascular Endothelium,Capillary Endotheliums,Endothelium, Capillary,Endotheliums, Capillary,Endotheliums, Vascular,Vascular Endotheliums
D005609	Free Radicals	Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. Free radicals include reactive oxygen and nitrogen species (RONS). They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.	Free Radical
D000109	Acetylcholine	A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.	2-(Acetyloxy)-N,N,N-trimethylethanaminium,Acetilcolina Cusi,Acetylcholine Bromide,Acetylcholine Chloride,Acetylcholine Fluoride,Acetylcholine Hydroxide,Acetylcholine Iodide,Acetylcholine L-Tartrate,Acetylcholine Perchlorate,Acetylcholine Picrate,Acetylcholine Picrate (1:1),Acetylcholine Sulfate (1:1),Bromoacetylcholine,Chloroacetylcholine,Miochol,Acetylcholine L Tartrate,Bromide, Acetylcholine,Cusi, Acetilcolina,Fluoride, Acetylcholine,Hydroxide, Acetylcholine,Iodide, Acetylcholine,L-Tartrate, Acetylcholine,Perchlorate, Acetylcholine