aquaporin 2

DEFINITION:

Also called WCH-CD, this water channel makes the principal cells of the inner medullary collecting duct in the kidneys more permeable to water. Lack of functional aquaporin-2 gene leads to a rare form of nephrogenic diabetes insipidus.

AQP2

DEFINITION:

Aquaporin-2.

phosphorylation

DEFINITION:

The metabolic process of introducing a phosphate group into an organic molecule.

protein kinase A

DEFINITION:

Cyclic AMP-dependent protein kinase. Protein kinase A is a necessary part of the molecular cascade that results in AQP2 insertion into the apical membrane. (JC)

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).

AQP2

DEFINITION:

Aquaporin-2.

plasma membrane

DEFINITION:

The structure enveloping a cell, enclosing the cytoplasm, and forming a selective permeability barrier; it consists of lipids, proteins, and some carbohydrates, the lipids thought to form a bilayer in which integral proteins are embedded to varying degrees.

renal cells

DEFINITION:

Kidney cells.

phosphorylation

DEFINITION:

The metabolic process of introducing a phosphate group into an organic molecule.

AQP2

DEFINITION:

Aquaporin-2.

incubated

DEFINITION:

1. Placed in an optimal situation for development, as by provision of the proper temperature and humidity for the growth of living cells, such as ova, microorganisms, or tissue cells.

2. Of or pertaining to a culture or a reaction mixture which is maintained at a fixed temperature.

synthesized

DEFINITION:

Produced by means of synthesis.

AQP2

DEFINITION:

Aquaporin-2.

endoplasmic reticulum

DEFINITION:

An ultramicroscopic organelle of nearly all cells of higher plants and animals, consisting of a more or less continuous system of membrane-bound cavities that ramify throughout the cytoplasm of a cell.

ER

DEFINITION:

Abbreviation for endoplasmic reticulum.

AQP2

DEFINITION:

Aquaporin-2.

ER

DEFINITION:

Abbreviation for endoplasmic reticulum.

washout

DEFINITION:

A cleansing or sweeping clean.

ER

DEFINITION:

Abbreviation for endoplasmic reticulum.

AQP2

DEFINITION:

Aquaporin-2.

phosphorylated

DEFINITION:

See phosphorylation.

phosphorylated AQP2

DEFINITION:

Phosphorylated aquaporin-2.

p-AQP2

DEFINITION:

Phosphorylated aquaporin-2.

Golgi

DEFINITION:

A part of a cell, named after the Nobel-prize-winning Italian neurologist and histologist, Camillo Golgi (1843-1926). Known as the Golgi complex or the Golgi apparatus, this portion of the cell is usually located near the cell nucleus and is a complex cup-like structure made up of several elements, each consisting of a number of flattened sacs (cisternae) with associated vacuoles and vesicles. Golgi complexes are membrane sites of the formation of the carbohydrate side chains of glycoproteins and mucopolysaccharides, and of other substances. The secretion vacuoles migrate through the cell membrane and release the glycoproteins and mucopolysaccharides, and thus play a role in internal and external secretion.

AQP2

DEFINITION:

Aquaporin-2.

transport

DEFINITION:

The movement of materials in biological systems, particularly into and out of cells and across epithelial layers.

Golgi

DEFINITION:

A part of a cell, named after the Nobel-prize-winning Italian neurologist and histologist, Camillo Golgi (1843-1926). Known as the Golgi complex or the Golgi apparatus, this portion of the cell is usually located near the cell nucleus and is a complex cup-like structure made up of several elements, each consisting of a number of flattened sacs (cisternae) with associated vacuoles and vesicles. Golgi complexes are membrane sites of the formation of the carbohydrate side chains of glycoproteins and mucopolysaccharides, and of other substances. The secretion vacuoles migrate through the cell membrane and release the glycoproteins and mucopolysaccharides, and thus play a role in internal and external secretion.

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).

regulated

DEFINITION:

1. Having been adjusted to a certain standard.

2. In biology, describing the adaptation of form or behavior of an organism to changed conditions.

concomitant

DEFINITION:

Accompanying; accessory; joined with another.

p-AQP2

DEFINITION:

Phosphorylated aquaporin-2.

hypothesis

DEFINITION:

A supposition that appears to explain a group of phenomena and is advanced as a basis for further investigation; a proposition that is subject to proof or to an experimental or statistical test.

AQP2

DEFINITION:

Aquaporin-2.

Golgi apparatus

DEFINITION:

See Golgi complex .

AQP2

DEFINITION:

Aquaporin-2.

phosphorylation

DEFINITION:

The metabolic process of introducing a phosphate group into an organic molecule.

constitutive

DEFINITION:

Produced constantly or in fixed amounts, regardless of environmental conditions or demand.

phosphorylation

DEFINITION:

The metabolic process of introducing a phosphate group into an organic molecule.

Golgi

DEFINITION:

A part of a cell, named after the Nobel-prize-winning Italian neurologist and histologist, Camillo Golgi (1843-1926). Known as the Golgi complex or the Golgi apparatus, this portion of the cell is usually located near the cell nucleus and is a complex cup-like structure made up of several elements, each consisting of a number of flattened sacs (cisternae) with associated vacuoles and vesicles. Golgi complexes are membrane sites of the formation of the carbohydrate side chains of glycoproteins and mucopolysaccharides, and of other substances. The secretion vacuoles migrate through the cell membrane and release the glycoproteins and mucopolysaccharides, and thus play a role in internal and external secretion.

cells

DEFINITION:

See definitions for "cell."

expressing

DEFINITION:

1. Indicating the flow of genetic information from gene to protein.

2. Regulating the process by which the effects of a gene are manifested.

3. Manifesting a heritable trait in an individual carrying the gene or genes that determine it.

mutated

DEFINITION:

1. Changed in form, quality, or some other characteristic.
2. In genetics, having undergone a permanent transmissible change in the genetic material, usually in a single gene. Also, an individual exhibiting such a change.

phosphorylation

DEFINITION:

The metabolic process of introducing a phosphate group into an organic molecule.

AQP2

DEFINITION:

Aquaporin-2.

routing

DEFINITION:

1. A course or way.

2. The area of the body through which a curative is introduced.

lysosomes

DEFINITION:

The minute bodies seen with the electron microscope in many types of cells, containing various hydrolytic enzymes and normally involved in the process of localized intracellular digestion. Injury to a lysosome is followed by release into the cell of the enzymes, which may damage the cell and give rise to wasting and other pathologic aspects of certain diseases, as in muscular dystrophy.

molecular

DEFINITION:

Of, pertaining to, or composed of molecules.

dominant

DEFINITION:

1. Exerting a ruling or controlling influence.

2. In genetics, capable of expression when carried by only one of a pair of homologous chromosomes.

3. A dominant allele or trait.

nephrogenic diabetes insipidus

DEFINITION:

A syndrome of polyuria and hyposthenuria caused by the failure of the renal tubules to reabsorb water in response to antidiuretic hormone, without disturbance in the renal filtration and solute excretion rates; the condition does not respond to exogenous vasopressin. It may be inherited as a rare X-linked trait or be acquired as a result of drug therapy or systemic disease.

mutation

DEFINITION:

1. A change in form, quality, or some other characteristic.

2. In genetics, a permanent transmissible change in the genetic material, usually in a single gene.

frameshift mutation - A mutation resulting from an addition or subtraction that is not an exact multiple of 3 base pairs in a coding sequence. From the point of mutation onwards, base triplets (codons) are read out of phase; the reading frame of the gene is changed, and a completely different set of amino acids is made into protein.

loss-of-function mutation - Impairment of the function of a gene caused by mutation.

missense mutation - A mutation that changes a codon so that it codes for a different amino acid.

nonsense mutation - A mutation in which one of the three terminator codons in the mRNA (UAG, amber; UAA, ochre; UGA, umber or opal), used to signal the end of a polypeptide, appears in the middle of a genetic message, causes premature termination of transcription, and releases incomplete, generally nonfunctional polypeptides from the ribosome.

point mutation - A mutation resulting from a change in a single base pair in the DNA molecule, caused by the substitution of one nucleotide for another.

phenotype

DEFINITION:

1. The entire physical, biochemical, and physiological makeup of an individual as determined both genetically and environmentally, as opposed to genotype.
2. The expression of a single gene or gene pair.

impaired routing

DEFINITION:

Denoting less-than-optimum performance of an object due to damage to the route (course, way) for travel from one location to another.

AQP2

DEFINITION:

Aquaporin-2.

permission

DEFINITION:

Formal consent; authorization.