aquaporin membrane water channels

DEFINITION:

A family of membrane channel proteins that serve as selective pores through which water crosses the plasma membranes of many human tissues and cell types.

biophysical

DEFINITION:

Pertaining to biophysics.

biologic membranes

DEFINITION:

The membranes of living organisms.

molecular

DEFINITION:

Of, pertaining to, or composed of molecules.

physiology

DEFINITION:

1. The science which treats of the functions of the living organism and its parts, and of the physical and chemical factors and processes involved.

2. The basic processes underlying the functioning of a species or class of organism, or any of its parts or processes.

water balance

DEFINITION:

Fluid balance.

pathophysiology

DEFINITION:

The physiology of abnormal states; specif.: the functional changes that accompany a particular syndrome or disease.

water balance disorders

DEFINITION:

Disorders caused by the disproportional relationship between the body's ingestion and excretion of water and electrolytes.

kidney

DEFINITION:

One of a pair of vertebrate organs situated in the body cavity near the spinal column that excrete waste products of metabolism, in man are bean-shaped organs about 4-1/2 inches long lying behind the peritoneum in a mass of fatty tissue, and consist chiefly of nephrons by which urine is secreted, collected, and discharged into a main cavity whence it is conveyed by the ureter to the bladder.

nephron

DEFINITION:

The anatomical and functional unit of the kidney, consisting of the renal corpuscle, the proximal convoluted tubule, the descending and ascending limbs of Henle's loop, the distal convoluted tubule, and the collecting tubule.

collecting duct

DEFINITION:

See under duct.

aquaporin-1

DEFINITION:

Also known as CHIP-28, aquaporin-1 is the major water channel of the red blood cells. In the kidneys, it is involved in the reabsorption of most of the waste filtered through the glomerula.

AQP1

DEFINITION:

Aquaporin-1.

proximal tubule

DEFINITION:

See proximal convoluted tubule or proximal straight tubule under tubule .

limb

DEFINITION:

1. One of the paired appendages of the body used in locomotion or grasping. In humans, an arm or leg (upper limb or lower limb) with all its component parts (e.g., arm, forearm, and hand). In embryology, the skeleton of each limb is divided into four main parts: the zonoskeleton , comprising the scapula and clavicle (as a unit) and the hip bone; the stylopodium , comprising the humerus and femur; the zygopodium , comprising the radius and ulna and the tibia and fibula; and the autopodium comprising the hand and the foot.

2. A structure or part resembling an arm or leg.

anterior limb - A limb-like structure situated in front of or in the forward part of a structure.

ascending limb - A limb-like structure which is moving or growing upward.

descending limb - A limb-like structure which is moving or growing downward.

posterior limb - A limb-like structure situated in back of or in the back part of a structure.

water reabsorption

DEFINITION:

1. The act or process of absorbing water again.

2. Resorption.

AQP2

DEFINITION:

Aquaporin-2.

collecting duct

DEFINITION:

See under duct.

principal cells

DEFINITION:

1. The fundamental cells of an organ, which usually have a specific function.

2. The principal cells are the chief cells, i.e., the most abundant cells of the parathyroid glands, being polygonal epithelial cells with a granular cytoplasm and vesicular nuclei, arranged in plates or cords, and which are rich in glycogen: the clear cells are more numerous and have relatively large nuclei and clear cytoplasm with few granules, while the dark cells are smaller with smaller and darker nuclei and finely granular cytoplasm with many granules. Intermediate forms also exist.

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).

regulate

DEFINITION:

1. To adjust to a certain standard.
2. In biology, to adapt the form or behavior of an organism to changed conditions.
3. To possess the power to form a whole embryo from stages before the gastrula.

collecting duct

DEFINITION:

See under duct.

water reabsorption

DEFINITION:

1. The act or process of absorbing water again.

2. Resorption.

regulation

DEFINITION:

1. The act of adjusting or state or being adjusted to a certain standard.
2. In biology, the adaptation of form or behavior of an organism to changed conditions.
3. The power to form a whole embryo from stages before the gastrula.

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.

trafficking

DEFINITION:

Acting as a transporter.

AQP2

DEFINITION:

Aquaporin-2.

intracellular

DEFINITION:

Situated or occurring within a cell or cells.

reservoir

DEFINITION:

1. A place or cavity for storage.
2. Cisterna.
3. An alternate or passive host or carrier that harbors pathogenic organisms, without injury to itself, and serves as a source from which other individuals can be infected. Called also reservoir host or reservoir of infection .

apical plasma membrane

DEFINITION:

Indicating the apex of the plasma membrane.

AQP2

DEFINITION:

Aquaporin-2.

regulation

DEFINITION:

1. The act of adjusting or state or being adjusted to a certain standard.
2. In biology, the adaptation of form or behavior of an organism to changed conditions.
3. The power to form a whole embryo from stages before the gastrula.

body water balance

DEFINITION:

See fluid balance.

regulation

DEFINITION:

1. The act of adjusting or state or being adjusted to a certain standard.
2. In biology, the adaptation of form or behavior of an organism to changed conditions.
3. The power to form a whole embryo from stages before the gastrula.

AQP2 expression

DEFINITION:

The process, or the regulation of the process, by which the effects of the aquaporin-2 gene are manifested.

multiple

DEFINITION:

1. More than one.

2. Occurring in or affecting various parts of the body at once.

3. The product of a quantity by an integer.

AQP2

DEFINITION:

Aquaporin-2.

inherited

DEFINITION:

That which has been acquired by transmission from parent to offspring.

acquired

DEFINITION:

Not genetic, but produced by influences originating outside the organism.

water balance disorders

DEFINITION:

Disorders caused by the disproportional relationship between the body's ingestion and excretion of water and electrolytes.

inherited

DEFINITION:

That which has been acquired by transmission from parent to offspring.

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.

acquired

DEFINITION:

Not genetic, but produced by influences originating outside the organism.

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.

AQP2 expression

DEFINITION:

The process, or the regulation of the process, by which the effects of the aquaporin-2 gene are manifested.

AQP2 expression

DEFINITION:

The process, or the regulation of the process, by which the effects of the aquaporin-2 gene are manifested.

congestive heart failure

DEFINITION:

A clinical syndrome due to heart disease, characterized by breathlessness and abnormal sodium and water retention, often resulting in edema. The congestion may occur in the lungs or peripheral circulation or both, depending on whether the heart failure is right-sided or general.

AQP3

DEFINITION:

Aquaporin-3.

AQP4

DEFINITION:

Aquaporin-4.

basolateral

DEFINITION:

Pertaining to the base and the sides.

water channels

DEFINITION:

Channels in a cell membrane that permit passage of water molecules; chemical substances such as vasopressin cause the opening of new channels and increase permeability.

kidney collecting duct

DEFINITION:

Also known as the tubulus renalis colligens , or renal collecting tubule: that structure of the kidney consisting of the arcuate renal tubule, straight collecting tubule, and papillary duct considered together.

AQP6

DEFINITION:

Aquaporin-6.

AQP7

DEFINITION:

Aquaporin-7.

expressed

DEFINITION:

1. Showing a detectable effect of a gene.

2. Made known; shown.

3. Squeezed out; extracted by pressing.

proximal tubule

DEFINITION:

See proximal convoluted tubule or proximal straight tubule under tubule .

AQP2

DEFINITION:

Aquaporin-2.

pathophysiology

DEFINITION:

The physiology of abnormal states; specif.: the functional changes that accompany a particular syndrome or disease.

water balance disorders

DEFINITION:

Disorders caused by the disproportional relationship between the body's ingestion and excretion of water and electrolytes.

permission

DEFINITION:

Formal consent; authorization.