water transport

DEFINITION:

The movement of water in biological systems.

collecting tubule

DEFINITION:

See under tubule.

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.

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).

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.

apical cell membrane

DEFINITION:

Pertaining to or located at the apex portion of the cell's membrane (the thin layer of tissue which covers the surface of the cell).

A cell

DEFINITION:

1. Alpha cell (definition 1).
2. Acidophil (definition 2).
3. Amacrine cell.

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.

hormone

DEFINITION:

A product of living cells that circulates in body fluids and produces a specific effect on the activity of cells remote from its point of origin; especially: one exerting a stimulatory effect on a cellular activity.

hypophysiotropic hormones - Hormones produced by the hypothalamus, usually releasing hormones (see below), which maintain the endocrine functions of cells of the adenohypophysis.

neurohormone - A hormone secreted by a specialized neuron into the bloodstream, the cerebrospinal fluid, or the intercellular spaces of the nervous system.

releasing hormones - Hormones elaborated in one structure that cause the release of hormones from another structure, such as those from the hypothalamus that act on the adenohypophysis. The term is applied to substances of established chemical identity, whereas substances of unknown chemical structure are called releasing factors .

shuttling

DEFINITION:

In biochemistry, referring to a mechanism for the transport of electrons or an organic group, or both, across a membrane.

Madin-Darby canine kidney cells

DEFINITION:

A line of canine epithelial cells that grow readily in culture and form confluent monolayers with relatively low trans-monolayer permeability (varies between clones). Often used as a general model for epithelial cells. (Author: John Lackie for Dictionary of Cell and Molecular Biology - Online.)

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.

expression

DEFINITION:

1. The aspect or appearance of the face (or surface of a cell) as determined by the physical or emotional state.

2. The act of squeezing or evacuating by pressure; a term used in pharmacy, surgery, and obstetrics.

3. The detectable effect of a gene.

4. A representation of value, relation, or the like (e.g., ratio).

construct

DEFINITION:

Something constructed especially by mental synthesis.

cells

DEFINITION:

See definitions for "cell."

clone

DEFINITION:

1. One or a group of genetically identical cells, organisms, or plants derived by vegetative reproduction from a single parent; also, a DNA population derived from a single hybrid DNA molecule by replication in a eukaryotic or bacterial host cell.

2. Used as a verb to denote the establishment of a clone.

semipermeable

DEFINITION:

Permitting the passage of certain molecules and hindering that of others.

basal

DEFINITION:

Pertaining to or situated near a base.

cells

DEFINITION:

See definitions for "cell."

indomethacin

DEFINITION:

A nonsteroidal anti-inflammatory agent; used in the treatment of rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, and acute gouty arthritis.

incubation

DEFINITION:

1. The development of the embryo in the eggs of oviparous animals.

2. The maintenance of an environment with controlled temperature, humidity, and oxygen for the development of an infant, especially of a premature one.

3. The development of an infectious disease from the entrance of the pathogen to the appearance of clinical symptoms.

4. The development of microorganisms or other cells in an appropriate medium under controlled environmental conditions, especially of temperature, to permit optimum growth.

5. The process of maintaining reaction mixtures at a given temperature for specified time periods for the development of chemical or enzymatic reactions.

arginine vasopressin

DEFINITION:

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

dDAVP

DEFINITION:

Also DDAVP. Trademark for preparation of desmopressin.

translocation

DEFINITION:

A structural chromosome aberration in which one segment of a chromosome is transferred to a nonhomologous chromosome, the result of breakage of both chromosomes with repair in abnormal arrangement.

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.

intracellular

DEFINITION:

Situated or occurring within a cell or cells.

apical membrane

DEFINITION:

See under membrane.

cells

DEFINITION:

See definitions for "cell."

dDAVP

DEFINITION:

Also DDAVP. Trademark for preparation of desmopressin.

maximal

DEFINITION:

The greatest possible, allowable, or appreciable; the reverse of minimal .

dDAVP

DEFINITION:

Also DDAVP. Trademark for preparation of desmopressin.

intracellular cAMP

DEFINITION:

Cyclic adenosine monophosphate within a cell.

dDAVP

DEFINITION:

Also DDAVP. Trademark for preparation of desmopressin.

basal

DEFINITION:

Pertaining to or situated near a base.

dDAVP

DEFINITION:

Also DDAVP. Trademark for preparation of desmopressin.

dDAVP

DEFINITION:

Also DDAVP. Trademark for preparation of desmopressin.

washout

DEFINITION:

A cleansing or sweeping clean.

basal

DEFINITION:

Pertaining to or situated near a base.

mimic

DEFINITION:

1. Mimetic, i.e., marked by stimulation of another bodily process or disease.

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.

water transport

DEFINITION:

The movement of water in biological systems.

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.

translocation

DEFINITION:

A structural chromosome aberration in which one segment of a chromosome is transferred to a nonhomologous chromosome, the result of breakage of both chromosomes with repair in abnormal arrangement.

collecting duct cells

DEFINITION:

The cells of the renal collecting tubule: the arcuate renal tubule, straight collecting tubule, and papillary duct considered together.

in vitro

DEFINITION:

Within a glass; observable in a test tube; in an artificial environment.

cell

DEFINITION:

1. Any one of the minute protoplasmic masses that make up organized tissue, consisting of a nucleus which is surrounded by cytoplasm which contains the various organelles and is enclosed in the cell or plasma membrane. A cell is the fundamental, structural, and functional unit of living organisms.

2. A small, more or less closed space.

neuroglial cells - The cells of the supportive tissue of the central nervous system (neuroglia); these non-neural cells are of three kinds: astrocytes, oligodendrocytes (collectively termed macroglia) and microglia.

reticular cells - The cells forming the reticular fibers of connective tissue; those forming the framework of lymph nodes, bone marrow, and spleen are part of the reticuloendothelial system and under appropriate stimulation may differentiate into macrophages.

stem cell - 1. Any precursor cell.

2. A blood cell progenitor, or mother cell, having the capacity for both replication and differentiation, and giving rise to various morphologically recognizable precursors of different blood cell lines, such as the proerythrocyte and myeloblast, which cannot self-replicate and must differentiate into more mature daughter cells.

model

DEFINITION:

1. Something that represents or simulates something else; a replica.
2. A reasonable facsimile of the body or any of its parts; used for demonstration and teaching purposes.
3. Cast, definition 5.
4. To imitate another's behavior; See modeling .
5. A hypothesis or theory.

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.

water transport

DEFINITION:

The movement of water in biological systems.

test

DEFINITION:

1. An examination or trial.

2. A significant chemical reaction.

3. A reagent.

4. A loose or rigid, secreted or agglutinated, protective shell or shell-like covering or exoskeleton, seen in various invertebrates, including certain protozoa and echinoderms.

putative

DEFINITION:

1. Commonly accepted or supposed.

2. Assumed to exist or to have existed.

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.

blockers

DEFINITION:

Things that obstruct passage or activity.

permission

DEFINITION:

Formal consent; authorization.