Vasoconstrictor
Encyclopedia : V : VA : VAS : Vasoconstrictor
Vasoconstriction is the constriction of blood vessels, in other words, when the lumen narrows. A vasoconstrictor, or vasopressor, is any substance or environmental stressor that acts to cause vasoconstriction. Many vasoconstrictors act on specific receptors, such as vasopressin receptors or adrenoreceptors. Vasoconstrictors are also used clinically to increase blood pressure or to reduce local blood flow. Exposure to moderately high levels of stress also induces vasoconstriction.
The opposite process, vasodilation, is the opening of blood vessels.
Vasoconstriction also occurs in superficial blood vessels of warm-blooded animals when their ambient environment is cold; this process diverts the flow of heated blood to the center of the animal, preventing the loss of heat.
Examples of vasoconstrictors
- Antihistamines
- Adrenalin
- Asymmetric dimethylarginine
- Caffeine
- Cannabis
- Catecholamines
- Decongestants
- Pseudoephedrine
- Norepinephrine
- Tetrahydrozoline hydrochloride (in eye drops)
- Thromboxane
See also
External links
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