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.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

vasopressin receptor

DEFINITION:

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

gene

DEFINITION:

A segment of a DNA molecule that contains all the information required for synthesis of a product (polypeptide chain or RNA molecule), including both coding and non-coding sequences. It is the biological unit of heredity, self-reproducing, and transmitted from parent to progeny. Each gene has a specific position (locus) on the chromosome map. From the standpoint of function, genes are conceived of as structural, operator, and regulatory genes.

wild-type gene - The normal allele of a gene, sometimes symbolized by +.

X-linked gene - A gene carried on the X chromosome; the corresponding trait, whether dominant or recessive, is always expressed in males, who have only one X chromosome. X linkage is used sometimes synonymously with sex linkage since no genetic disorders have as yet been associated with genes on the Y chromosome.

transcript

DEFINITION:

1. A term used to refer to the various segment(s) of messenger RNA (MRNA) that result from transcription of a gene.

2. A written, printed, or typed copy.

3. An official copy, especially of a student's educational record.

encodes

DEFINITION:

Converts (a message, information, etc.) into code.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

transcript

DEFINITION:

1. A term used to refer to the various segment(s) of messenger RNA (MRNA) that result from transcription of a gene.

2. A written, printed, or typed copy.

3. An official copy, especially of a student's educational record.

encodes

DEFINITION:

Converts (a message, information, etc.) into code.

variant

DEFINITION:

1. Something that differs in some characteristic from the class to which it belongs; as a variant of a disease, trait, species, etc.

2. Exhibiting such variation.

sequence

DEFINITION:

1. A connected series of events or things.
2. In dysmorphology, a pattern of multiple anomalies derived from a single known or presumed prior anomaly or mechanical factor.
3. In molecular biology, often used to refer to DNA having a particular nucleotide composition or occurring in a particular region of the genome.

corresponding

DEFINITION:

Agreeing or conforming.

putative

DEFINITION:

1. Commonly accepted or supposed.

2. Assumed to exist or to have existed.

transmembrane

DEFINITION:

Extending across a membrane, usually referring to a protein subunit that is exposed on both sides of a cell membrane.

domain

DEFINITION:

A compact globular structure composed of one section of a polypeptide chain that constitutes a recognizable unit of the tertiary structure of a protein. Domains may fold up independently and maintain their native conformation when the connecting sections of the chain are broken.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

transcript

DEFINITION:

1. A term used to refer to the various segment(s) of messenger RNA (MRNA) that result from transcription of a gene.

2. A written, printed, or typed copy.

3. An official copy, especially of a student's educational record.

translated

DEFINITION:

1. Changed from one place, state, or form to another.

2. Turned into one's own or another language.

See also "translation" for application of the term in genetics.

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.

collecting tubules

DEFINITION:

See under tubule.

protein

DEFINITION:

Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur, the characteristic element being nitrogen, and which are widely distributed in plants and animals. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a-amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins, and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. They serve as enzymes, structural elements, hormones, immunoglobulins, etc., and are involved in oxygen transport, muscle contraction, electron transport, and other activities throughout the body, and in photosynthesis.

binding protein - any of a number of plasma proteins (See below) that bind to hormones of low solubility (chiefly the thyroid and steroid hormones), thus providing a transport system for them; some are specific for particular hormones, while others bind to any sparingly soluble hormones. Called also carrier protein or transport protein (See below).

carrier proteins - A binding protein (See above).

plasma proteins - The hundreds of different proteins present in blood plasma, including carrier proteins (such as albumin, transferrin, and haptoglobin), fibrinogen and other coagulation factors, complement components, immunoglobulins, enzyme inhibitors, precursors of substances such as angiotensin and bradykinin, and many other types of proteins.

transport protein - binding protein (See above).

encoded

DEFINITION:

Converted (a message, information, etc.) into code.

transcript

DEFINITION:

1. A term used to refer to the various segment(s) of messenger RNA (MRNA) that result from transcription of a gene.

2. A written, printed, or typed copy.

3. An official copy, especially of a student's educational record.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

variant

DEFINITION:

1. Something that differs in some characteristic from the class to which it belongs; as a variant of a disease, trait, species, etc.

2. Exhibiting such variation.

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.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

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.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

variant

DEFINITION:

1. Something that differs in some characteristic from the class to which it belongs; as a variant of a disease, trait, species, etc.

2. Exhibiting such variation.

binding

DEFINITION:

1. Wrapping with a binder or bandage.

2. Forming a weak, reversible chemical bond, e.g., antigen to antibody or hormone to receptor.

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).

variant

DEFINITION:

1. Something that differs in some characteristic from the class to which it belongs; as a variant of a disease, trait, species, etc.

2. Exhibiting such variation.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

down-regulates

DEFINITION:

A decrease in the number of aquaporin 2 (AQP2) water channels, i.e., regulation to a lower number of channels expressed on the luminal membrane (adapted from D. Bichet's definition).

A reduction in the levels of AQP2 protein in the collecting duct cells. Since AQP2 is essential for reabsorption of water from the collecting duct lumen back to the circulation, the absence or reduced levels of AQP2 (downregulation) results in the development of polyuria. Thus the conditions associated with this downregulation of AQP2 share many common features with the inherited forms of NDI (with mutations in vasopressin V2 receptor) since this condition is also associated with a reduced/absence of regulation of AQP2. This regulation is important for keeping the levels of AQP2 protein up, but it is also extremely important in regulating the trafficking of AQP2 from the reservoir in small vesicles to the apical plasma membrane (its active site for water reabsorption—the site where the water channel faces the water to be reabsorbed). This is why the studies of the very common acquired forms of NDI are very important in connection with inherited NDI (the shared elements of regulation or rather dysregulation) (adapted from S. Nielsen's definition). See downregulation.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

formation

DEFINITION:

1. The process of giving shape or form; the creation of an entity, or of a structure of definite shape.

2. A structure of definite shape.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

variant

DEFINITION:

1. Something that differs in some characteristic from the class to which it belongs; as a variant of a disease, trait, species, etc.

2. Exhibiting such variation.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

variant

DEFINITION:

1. Something that differs in some characteristic from the class to which it belongs; as a variant of a disease, trait, species, etc.

2. Exhibiting such variation.

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.

negative

DEFINITION:

1. Marked by denial, prohibition, or refusal.
2. Not positive or constructive.
3. Less than zero.
4. Being, relating to, or charged with electricity of which the electron is the elementary unit.
5. Having the light and dark parts opposite to what they were in the original photographic subject.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

variant

DEFINITION:

1. Something that differs in some characteristic from the class to which it belongs; as a variant of a disease, trait, species, etc.

2. Exhibiting such variation.

affect

DEFINITION:

1. To produce an effect on; influence.

2. The external expression of emotion attached to ideas or mental representations of objects.

G protein

DEFINITION:

Any of a family of similar heterotrimeric proteins of the intracellular portion of the plasma membrane that bind activated receptor complexes and, through conformational changes and cyclic binding and hydrolysis of GTP, directly or indirectly effect alterations in channel gating and so couple cell surface receptors to intracellular responses. Some G proteins are named for their activities, e.g., G_s stimulates and G_I inhibits enzyme activity.

coupled

DEFINITION:

See coupling.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

sequence

DEFINITION:

1. A connected series of events or things.
2. In dysmorphology, a pattern of multiple anomalies derived from a single known or presumed prior anomaly or mechanical factor.
3. In molecular biology, often used to refer to DNA having a particular nucleotide composition or occurring in a particular region of the genome.

residues

DEFINITION:

1. That which remains after the removal of other substances.
2. In biochemistry, the portion of a molecule that remains after it has lost some of its components, as an amino acid residue, which loses a water molecule when it is joined to another amino acid.

corresponding

DEFINITION:

Agreeing or conforming.

C-terminal

DEFINITION:

The end of the peptide chain carrying the free alpha carboxyl group of the last amino acid, conventionally written to the right.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

variant

DEFINITION:

1. Something that differs in some characteristic from the class to which it belongs; as a variant of a disease, trait, species, etc.

2. Exhibiting such variation.

down-regulates

DEFINITION:

A decrease in the number of aquaporin 2 (AQP2) water channels, i.e., regulation to a lower number of channels expressed on the luminal membrane (adapted from D. Bichet's definition).

A reduction in the levels of AQP2 protein in the collecting duct cells. Since AQP2 is essential for reabsorption of water from the collecting duct lumen back to the circulation, the absence or reduced levels of AQP2 (downregulation) results in the development of polyuria. Thus the conditions associated with this downregulation of AQP2 share many common features with the inherited forms of NDI (with mutations in vasopressin V2 receptor) since this condition is also associated with a reduced/absence of regulation of AQP2. This regulation is important for keeping the levels of AQP2 protein up, but it is also extremely important in regulating the trafficking of AQP2 from the reservoir in small vesicles to the apical plasma membrane (its active site for water reabsorption—the site where the water channel faces the water to be reabsorbed). This is why the studies of the very common acquired forms of NDI are very important in connection with inherited NDI (the shared elements of regulation or rather dysregulation) (adapted from S. Nielsen's definition). See downregulation.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

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.

variant

DEFINITION:

1. Something that differs in some characteristic from the class to which it belongs; as a variant of a disease, trait, species, etc.

2. Exhibiting such variation.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

wild-type

DEFINITION:

In genetics, the standard phenotype for any experimental organism; also a gene that determines a standard phenotypic trait. See also under gene .

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

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.

formation

DEFINITION:

1. The process of giving shape or form; the creation of an entity, or of a structure of definite shape.

2. A structure of definite shape.

V

DEFINITION:

Valine; vanadium; vision; volt; volume.

permission

DEFINITION:

Formal consent; authorization.