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.

antidiuretic

DEFINITION:

1. Suppressing the rate of urine formation.

2. An agent that suppresses urine formation.

arginine vasopressin

DEFINITION:

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

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.

X-linked nephrogenic diabetes insipidus

DEFINITION:

A form of diabetes insipidus, inherited as an X-linked trait, caused by 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.

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.

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-receptor

DEFINITION:

See under "receptor."

molecular

DEFINITION:

Of, pertaining to, or composed of molecules.

genetic

DEFINITION:

1. Relating to or determined by the origin, development, or causal antecedents of something.

2. Of, relating to, or being a gene.

clinical symptoms

DEFINITION:

Symptoms observed while in a clinical setting.

urinary osmolality

DEFINITION:

The concentration of osmotically active particles in solution (in this case, urine) expressed in terms of osmoles of solute per kilogram of solvent. The osmolality is directly proportional to the colligative properties of solutions: osmotic pressure, boiling point elevation, freezing point depression, and vapor pressure lowering.

administration

DEFINITION:

1. The act of dispensing.

2. Application, as of a salve, medicine, etc.

arginine vasopressin

DEFINITION:

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

dDAVP

DEFINITION:

Also DDAVP. Trademark for preparation of desmopressin.

mutations

DEFINITION:

1. Changes in form, quality, or some other characteristic.

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.

histiocytosis X

DEFINITION:

A rare childhood disease in which there is an overgrowth of a type of tissue cell called a histiocyte. The cause is unknown, but it probably results from a disturbance of the immune system.

In the mildest form of the disease, rapid cell growth occurs in one bone only, usually affecting the skull, clavicle, or a rib or vertebra, causing swelling and pain. The chances of recovery are good in these cases.

The most severe, and least common, form of the disease affects infants. This form of the disease behaves like advanced leukemia, leading rapidly to death.

central diabetes insipidus

DEFINITION:

See under diabetes insipidus.

mutations

DEFINITION:

1. Changes in form, quality, or some other characteristic.

V2-receptor

DEFINITION:

See under "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.

genetic

DEFINITION:

1. Relating to or determined by the origin, development, or causal antecedents of something.

2. Of, relating to, or being a gene.

X-linked nephrogenic diabetes insipidus

DEFINITION:

A form of diabetes insipidus, inherited as an X-linked trait, caused by 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.

V2-receptor

DEFINITION:

See under "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.