Vasoconstrictor

A vasoconstrictor, also vasopressor or simply pressor, is any substance that acts to cause vasoconstriction (narrowing of the lumena of blood vessels) and usually results in an increase of the blood pressure. (The opposite process, vasodilation, is the opening of blood vessels. )

Many vasoconstrictors also cause pupil dilation.

Uses
Vasoconstrictors are used in medicine to treat hypotension and as topical decongestants.

Mechanism
Many vasoconstrictors act on specific receptors, such as vasopressin receptors or adrenoreceptors.

Causes
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.

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
Vasoconstrictors include systemic and topical. For example, pseudoephedrine is available systemic (i.e. orally ingested tablets like Sudafed), and topical (such as nose sprays like phenylephrine Neo-synephrine, and eye drops for pupil dilation purposes)


 * Adenosine triphosphate
 * Amphetamines
 * Antihistamines
 * Asymmetric dimethylarginine
 * Bright light
 * Catecholamines
 * Cocaine
 * Cold (water, air, etc.)
 * Decongestants
 * Elevated sound levels
 * Endothelin
 * Ergine
 * LSD
 * Methylphenidate
 * Neuropeptide Y
 * Norepinephrine
 * Phenylephrine
 * Pseudoephedrine
 * Psilocybin
 * Stimulants
 * Tetrahydrozoline hydrochloride (in eye drops)
 * Thromboxane