Vasoconstrictor Agents
Drugs used to cause constriction of the blood vessels.
Norbornanes
Vasoconstriction
The physiological narrowing of BLOOD VESSELS by contraction of the VASCULAR SMOOTH MUSCLE.
Phenylephrine
Angiotensin II
An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.
Norepinephrine
Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.
Vascular Resistance
The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.
Muscle, Smooth, Vascular
The nonstriated involuntary muscle tissue of blood vessels.
Blood Pressure
Endothelins
21-Amino-acid peptides produced by vascular endothelial cells and functioning as potent vasoconstrictors. The endothelin family consists of three members, ENDOTHELIN-1; ENDOTHELIN-2; and ENDOTHELIN-3. All three peptides contain 21 amino acids, but vary in amino acid composition. The three peptides produce vasoconstrictor and pressor responses in various parts of the body. However, the quantitative profiles of the pharmacological activities are considerably different among the three isopeptides.
Endothelin-1
A 21-amino acid peptide produced in a variety of tissues including endothelial and vascular smooth-muscle cells, neurons and astrocytes in the central nervous system, and endometrial cells. It acts as a modulator of vasomotor tone, cell proliferation, and hormone production. (N Eng J Med 1995;333(6):356-63)
Mesenteric Arteries
Sympathetic Nervous System
The thoracolumbar division of the autonomic nervous system. Sympathetic preganglionic fibers originate in neurons of the intermediolateral column of the spinal cord and project to the paravertebral and prevertebral ganglia, which in turn project to target organs. The sympathetic nervous system mediates the body's response to stressful situations, i.e., the fight or flight reactions. It often acts reciprocally to the parasympathetic system.
Vasomotor System
The neural systems which act on VASCULAR SMOOTH MUSCLE to control blood vessel diameter. The major neural control is through the sympathetic nervous system.
Receptors, Endothelin
Cell surface proteins that bind ENDOTHELINS with high affinity and trigger intracellular changes which influence the behavior of cells.
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid
Vasodilation
The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.
Vasodilator Agents
Drugs used to cause dilation of the blood vessels.
Methoxamine
An alpha-1 adrenergic agonist that causes prolonged peripheral VASOCONSTRICTION.
Receptor, Endothelin A
A subtype of endothelin receptor found predominantly in the VASCULAR SMOOTH MUSCLE. It has a high affinity for ENDOTHELIN-1 and ENDOTHELIN-2.
Renal Circulation
The circulation of the BLOOD through the vessels of the KIDNEY.
Tyramine
An indirect sympathomimetic. Tyramine does not directly activate adrenergic receptors, but it can serve as a substrate for adrenergic uptake systems and monoamine oxidase so it prolongs the actions of adrenergic transmitters. It also provokes transmitter release from adrenergic terminals. Tyramine may be a neurotransmitter in some invertebrate nervous systems.
Nitric Oxide
A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.
Thromboxane A2
An unstable intermediate between the prostaglandin endoperoxides and thromboxane B2. The compound has a bicyclic oxaneoxetane structure. It is a potent inducer of platelet aggregation and causes vasoconstriction. It is the principal component of rabbit aorta contracting substance (RCS).
Receptor, Endothelin B
A subtype of endothelin receptor found predominantly in the KIDNEY. It may play a role in reducing systemic ENDOTHELIN levels.
Arterioles
Endothelium, Vascular
Hemodynamics
Dose-Response Relationship, Drug
Prostaglandin Endoperoxides, Synthetic
Urotensins
Teleost hormones. A family of small peptides isolated from urophyses of bony fishes. They have many different physiological effects, including long-lasting hypotensive activity and have been proposed as antihypertensives. There are at least four different compounds: urotensin I, urotensin II, urotensin III, and urotensin IV.
NG-Nitroarginine Methyl Ester
A non-selective inhibitor of nitric oxide synthase. It has been used experimentally to induce hypertension.
Potassium Chloride
Indomethacin
A non-steroidal anti-inflammatory agent (NSAID) that inhibits the enzyme cyclooxygenase necessary for the formation of prostaglandins and other autacoids. It also inhibits the motility of polymorphonuclear leukocytes.
Rats, Sprague-Dawley
Receptors, Thromboxane
Nitroprusside
A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins.
Dogs
Splanchnic Circulation
The circulation of blood through the BLOOD VESSELS supplying the abdominal VISCERA.
Serotonin
A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.
Muscle Tonus
Nordefrin
A norepinephrine derivative used as a vasoconstrictor agent.
Hydroxyeicosatetraenoic Acids
Eicosatetraenoic acids substituted in any position by one or more hydroxy groups. They are important intermediates in a series of biosynthetic processes leading from arachidonic acid to a number of biologically active compounds such as prostaglandins, thromboxanes, and leukotrienes.
Nitric Oxide Synthase
An NADPH-dependent enzyme that catalyzes the conversion of L-ARGININE and OXYGEN to produce CITRULLINE and NITRIC OXIDE.
Prostaglandins
Acetylcholine
Viper Venoms
Venoms from SNAKES of the viperid family. They tend to be less toxic than elapid or hydrophid venoms and act mainly on the vascular system, interfering with coagulation and capillary membrane integrity and are highly cytotoxic. They contain large amounts of several enzymes, other factors, and some toxins.
Peptides, Cyclic
Adrenergic alpha-Antagonists
Drugs that bind to but do not activate alpha-adrenergic receptors thereby blocking the actions of endogenous or exogenous adrenergic agonists. Adrenergic alpha-antagonists are used in the treatment of hypertension, vasospasm, peripheral vascular disease, shock, and pheochromocytoma.
Sumatriptan
A serotonin agonist that acts selectively at 5HT1 receptors. It is used in the treatment of MIGRAINE DISORDERS.
Rats, Wistar
Arginine Vasopressin
The predominant form of mammalian antidiuretic hormone. It is a nonapeptide containing an ARGININE at residue 8 and two disulfide-linked cysteines at residues of 1 and 6. Arg-vasopressin is used to treat DIABETES INSIPIDUS or to improve vasomotor tone and BLOOD PRESSURE.
Adrenergic alpha-1 Receptor Agonists
Laser-Doppler Flowmetry
Blood Vessels
Any of the tubular vessels conveying the blood (arteries, arterioles, capillaries, venules, and veins).
Phentolamine
Enzyme Inhibitors
Kidney
Astringents
Bretylium Compounds
Bretylium compounds are pharmaceutical agents, primarily used in the treatment of life-threatening ventricular arrhythmias, that work by stabilizing the cardiac membrane and inhibiting the release of norepinephrine from sympathetic nerve endings.
Sympathetic Fibers, Postganglionic
Nerve fibers which project from sympathetic ganglia to synapses on target organs. Sympathetic postganglionic fibers use norepinephrine as transmitter, except for those innervating eccrine sweat glands (and possibly some blood vessels) which use acetylcholine. They may also release peptide cotransmitters.
Nitroarginine
An inhibitor of nitric oxide synthetase which has been shown to prevent glutamate toxicity. Nitroarginine has been experimentally tested for its ability to prevent ammonia toxicity and ammonia-induced alterations in brain energy and ammonia metabolites. (Neurochem Res 1995:200(4):451-6)