vasopressin receptor

DEFINITION:

A molecular structure to which the hormone, vasopressin, binds. See also receptor .

antagonist

DEFINITION:

1. A muscle whose action is the direct opposite of that of another muscle.

2. A substance that tends to nullify the action of another, as a drug that binds to a cell receptor without eliciting a biological response, blocking binding of substances that could elicit such responses.

3. A tooth in one jaw that articulates with a tooth in the other jaw.

beta

DEFINITION:

[B, β] The second letter of the Greek alphabet.

As Beta - The beets, a genus of herbaceous plants of the family Chenopodiaceae. Beta vulgaris (L.) is the sugar beet, a commercial source of sucrose. The leafy tops of beets are rich in oxalates and can cause oxalate poisoning in animals that eat them in large amounts.

beta

DEFINITION:

[B, β] The second letter of the Greek alphabet.

As Beta - The beets, a genus of herbaceous plants of the family Chenopodiaceae. Beta vulgaris (L.) is the sugar beet, a commercial source of sucrose. The leafy tops of beets are rich in oxalates and can cause oxalate poisoning in animals that eat them in large amounts.

beta

DEFINITION:

[B, β] The second letter of the Greek alphabet.

As Beta - The beets, a genus of herbaceous plants of the family Chenopodiaceae. Beta vulgaris (L.) is the sugar beet, a commercial source of sucrose. The leafy tops of beets are rich in oxalates and can cause oxalate poisoning in animals that eat them in large amounts.

acid

DEFINITION:

Any of a large class of sour chemical substances which are normally water-soluble, that are capable of reacting with a base to form a salt, that redden litmus, that are hydrogen-containing molecules or ions able to give up a proton to a base, or that are substances able to accept an unshared pair of electrons from a base.

tyrosine

DEFINITION:

A crystallizable, nonessential amino acid, ß-p-hydroxyphenylalanine, found in most proteins and synthesized metabolically from phenylalanine; it is a precursor of thyroid hormones, catecholamines, and melanin. Symbols Tyr and Y.

valine

DEFINITION:

An essential amino acid, alpha-amino-isovalerianic acid, produced by the digestion or hydrolytic decomposition of proteins; it is essential for optimal growth in infants and for nitrogen equilibrium in human adults.

arginine vasopressin

DEFINITION:

Vasopressin containing arginine, as that from most mammals, including man.

antagonist

DEFINITION:

1. A muscle whose action is the direct opposite of that of another muscle.

2. A substance that tends to nullify the action of another, as a drug that binds to a cell receptor without eliciting a biological response, blocking binding of substances that could elicit such responses.

3. A tooth in one jaw that articulates with a tooth in the other jaw.

potent

DEFINITION:

Powerful; effective.

radioiodinated

DEFINITION:

Involving the use of a radioiodine.

peptide

DEFINITION:

Any member of a class of compounds of low molecular weight which yield two or more amino acids on hydrolysis. Formed by loss of water from the NH₂ and COOH groups of adjacent amino acids, they are known as di-, tri-, tetra- [etc.] peptides, depending on the number of amino acids in the molecule. Peptides form the constituent parts of proteins.

bind

DEFINITION:

To form a weak, reversible chemical bond, e.g., antigen to antibody or hormone to receptor.

vasopressin

DEFINITION:

1. One of two octapeptide hormones formed by the neuronal cells of the hypothalamic nuclei and stored in the posterior lobe of the pituitary gland (neurohypophysis), the other being oxytocin. It stimulates the contraction of the muscular tissue of the capillaries and arterioles, raising the blood pressure. It promotes contraction of the intestinal musculature and increases peristalsis, and also exerts some contractile influence on the uterus. It also has a specific effect on the epithelial cells of the distal portion of the uriniferous tubule, augmenting resorption of water independently of solutes, resulting in concentration of urine and dilution of blood serum. Its rate of secretion is regulated chiefly by the osmolarity of the plasma.

2. [USP], A pharmaceutical preparation of the same principle, prepared synthetically or obtained from the posterior pituitary of healthy domestic animals used for food by man; used mainly as an antidiuretic in the treatment of acute or chronic diabetes insipidus, administered intramuscularly as a test of hypothalamo-neurohypophysial-renal function in distinguishing central from nephrogenic diabetes insipidus; it may also be used to stimulate smooth muscle tissue, especially to induce vasoconstriction in the presence of hemorrhage. Called also antidiuretic hormone (ADH).

V2

DEFINITION:

Vasopressin-2. See vasopressin-2 gene and vasopressin-2 receptor.

receptors

DEFINITION:

See definitions under "receptor."

dissociation constant

DEFINITION:

An equilibrium constant, expressed in concentrations, describing the dissociation of a molecule or ion into its components. Symbol K_d. See also acid dissociation constant and base dissociation constant . Called also ionization constant .

ligand

DEFINITION:

1. A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme.
2. A molecule that donates or accepts a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex.

vasopressin V2 receptor

DEFINITION:

The molecular structure within a cell or on the surface to which the antidiuretic hormone, arginine vasopressin binds.

localization

DEFINITION:

1. The determination of the site or place of any process or lesion.
2. Restriction to a circumscribed or limited area.
3. Prelocalization.

characterization

DEFINITION:

1. Indicating the character or peculiar quality of a person or thing; indicating a typical or distinctive quality.

2. Indicating a distinguishing feature or quality.

selective

DEFINITION:

Having a high degree of selectivity.

vasopressin

DEFINITION:

1. One of two octapeptide hormones formed by the neuronal cells of the hypothalamic nuclei and stored in the posterior lobe of the pituitary gland (neurohypophysis), the other being oxytocin. It stimulates the contraction of the muscular tissue of the capillaries and arterioles, raising the blood pressure. It promotes contraction of the intestinal musculature and increases peristalsis, and also exerts some contractile influence on the uterus. It also has a specific effect on the epithelial cells of the distal portion of the uriniferous tubule, augmenting resorption of water independently of solutes, resulting in concentration of urine and dilution of blood serum. Its rate of secretion is regulated chiefly by the osmolarity of the plasma.

2. [USP], A pharmaceutical preparation of the same principle, prepared synthetically or obtained from the posterior pituitary of healthy domestic animals used for food by man; used mainly as an antidiuretic in the treatment of acute or chronic diabetes insipidus, administered intramuscularly as a test of hypothalamo-neurohypophysial-renal function in distinguishing central from nephrogenic diabetes insipidus; it may also be used to stimulate smooth muscle tissue, especially to induce vasoconstriction in the presence of hemorrhage. Called also antidiuretic hormone (ADH).

ligand

DEFINITION:

1. A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme.
2. A molecule that donates or accepts a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex.