antagonize

DEFINITION:

1. To act in direct opposition.

2. To nullify; i.e., the action of a substance that tends to nullify the action of another, as a drug that binds to a cell receptor without eliciting a biological response, blocking binding or substances that could elicit such responses.

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).

absorption

DEFINITION:

1. The uptake of substances into or across tissues, e.g., skin, intestine, and kidney tubules.


2. In radiology, the taking up of energy by matter with which the radiation interacts.

thick ascending limb

DEFINITION:

See "loop of Henle."

absorption

DEFINITION:

1. The uptake of substances into or across tissues, e.g., skin, intestine, and kidney tubules.


2. In radiology, the taking up of energy by matter with which the radiation interacts.

collecting duct

DEFINITION:

See under duct.

blockade

DEFINITION:

1. Receptor blockade, the blocking of the effect of a hormone or neurotransmitter at a cell-surface receptor by a pharmacologic antagonist bound to the receptor.

2. In histochemistry, a chemical reaction that by modifying certain chemical groups blocks a specific staining method.

3. Regional anesthesia.

synthesis

DEFINITION:

The artificial building up of a chemical compound, by the union of its elements or from other suitable starting materials.

urinary concentration

DEFINITION:

The increase in strength of urine by evaporation.

antidiuretic

DEFINITION:

1. Suppressing the rate of urine formation.

2. An agent that suppresses urine formation.

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.

NDI

DEFINITION:

Nephrogenic diabetes insipidus.

etiologies

DEFINITION:

The studies or theories of the factors that cause disease and the method of their introduction to the host; the causes or origin of a disease or disorder.

renal

DEFINITION:

Pertaining to the kidney.

cyclooxygenase-2 (COX-2)

DEFINITION:

An activity of prostaglandin endoperoxide synthase. COX-2 is found in cells in the kidney glomerulus and in small blood vessels in the kidney. This suggests that it helps regulate the movement of the blood in the kidneys. (JC/JTRAN-620)

hypothesized

DEFINITION:

Adopted as a hypothesis.

NDI

DEFINITION:

Nephrogenic diabetes insipidus.

COX-2

DEFINITION:

Cyclooxygenase-2. (See JTRAN-620.)

inhibitor

DEFINITION:

1. Any substance that interferes with a chemical reaction, growth, or other biological activity.

2. A chemical substance that inhibits an enzyme reaction.

polyuria

DEFINITION:

The passage of a large volume of urine in a given period, a characteristic of diabetes.

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).

thick ascending limb

DEFINITION:

See "loop of Henle."

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.

collecting duct

DEFINITION:

See under duct.

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.

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.

immunohistochemistry

DEFINITION:

See immunohistochemical .

kidneys

DEFINITION:

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.

lithium-induced NDI

DEFINITION:

Nephrogenic diabetes insipidus, acquired as a result of lithium drug therapy.

COX-2

DEFINITION:

Cyclooxygenase-2. (See JTRAN-620.)

inhibition

DEFINITION:

Arrest or restraint of a process.

Sprague-Dawley rats

DEFINITION:

A strain of albino rats developed by the Sprague-Dawley Animal Company, widely used in experimental work because of their calmness and ease of handling.

COX-2

DEFINITION:

Cyclooxygenase-2. (See JTRAN-620.)

inhibitor

DEFINITION:

1. Any substance that interferes with a chemical reaction, growth, or other biological activity.

2. A chemical substance that inhibits an enzyme reaction.

orally

DEFINITION:

Pertaining to the mouth; taken through or applied in the mouth, as an oral medication or an oral thermometer.

COX-2

DEFINITION:

Cyclooxygenase-2. (See JTRAN-620.)

inhibitor

DEFINITION:

1. Any substance that interferes with a chemical reaction, growth, or other biological activity.

2. A chemical substance that inhibits an enzyme reaction.

polyuria

DEFINITION:

The passage of a large volume of urine in a given period, a characteristic of diabetes.

urine 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.

COX-2

DEFINITION:

Cyclooxygenase-2. (See JTRAN-620.)

inhibition

DEFINITION:

Arrest or restraint of a process.

AQP2

DEFINITION:

Aquaporin-2.

immunohistochemistry

DEFINITION:

See immunohistochemical .

AQP2

DEFINITION:

Aquaporin-2.

COX-2

DEFINITION:

Cyclooxygenase-2. (See JTRAN-620.)

inhibition

DEFINITION:

Arrest or restraint of a process.

lithium-induced NDI

DEFINITION:

Nephrogenic diabetes insipidus, acquired as a result of lithium drug therapy.

upregulation

DEFINITION:

An increase in the number of receptors for a chemical or drug on cell surfaces in a given area so that the cells are more reactive to the effects of the agent. See also downregulation .

AQP2

DEFINITION:

Aquaporin-2.

COX-2

DEFINITION:

Cyclooxygenase-2. (See JTRAN-620.)

inhibitor

DEFINITION:

1. Any substance that interferes with a chemical reaction, growth, or other biological activity.

2. A chemical substance that inhibits an enzyme reaction.

therapeutic

DEFINITION:

A term meaning "related to treatment." The therapeutic dose of a drug is the amount required to have a beneficial effect.

antidiuresis

DEFINITION:

Suppression of urinary excretion.

NDI

DEFINITION:

Nephrogenic diabetes insipidus.

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.