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.

angiotensin II

DEFINITION:

An octapeptide hormone formed by the action of angiotensin-converting enzyme (peptidyl-dipeptidase A) on angiotensin I, chiefly in the lungs but also at other sites, including the blood vessel walls, uterus, and brain. It is a powerful vasopressor and stimulator of aldosterone secretion by the adrenal cortex, and it also functions as a neurotransmitter. Its vasopressor action raises blood pressure and diminishes fluid loss in the kidney by restricting blood flow.

malignant

DEFINITION:

1. Tending to become progressively worse and to result in death.
2. Having the properties of anaplasia, invasion, and metastasis; said of tumors.

hypertension

DEFINITION:

Abnormally high blood pressure and especially arterial blood pressure.

sodium

DEFINITION:

A silver white soft waxy ductile element of the alkali metal group that occurs abundantly in nature in combined form and is very active chemically.

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.

medullary

DEFINITION:

Pertaining to the marrow or to any medulla; resembling marrow.

transporters

DEFINITION:

Transport proteins; often specifically a transport protein that after binding one to several molecules of substrate, undergoes a conformational change that moves only the substrate across the membrane. Different types facilitate movement with (symport) and against (antiport) concentration gradients.

blood pressure

DEFINITION:

1. The pressure of blood against the walls of any blood vessel.

2. The pressure of the blood on the walls of the arteries, dependent on the energy of the heart action, the elasticity of the walls of the arteries, and the volume and viscosity of the blood. The maximum or systolic blood pressure occurs near the end of the stroke output of the left ventricle of the heart. The minimum or diastolic blood pressure occurs late in ventricular diastole. Mean blood pressure is the average of the blood pressure levels, and basic blood pressure is that during quiet rest or basal conditions. See also hypertension and hypotension.

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.

inner medullary

DEFINITION:

Pertaining to or situated in the inner medulla.

base

DEFINITION:

1. The main ingredient of a compound.

2. In chemistry, the nonacid part of a salt; a substance that combines with acids to form salts; a substance that dissociates to give hydroxide ions in aqueous solutions; a substance whose molecule or ion can combine with a proton (hydrogen ion); a substance capable of donating a pair of electrons (to an acid) for the formation of a coordinate covalent bond.

3. In genetics, a nucleotide, particularly one in a nucleic acid sequence.

4. Indicating the bottom of an organ or other object.

5. Foundation.

6. A side or face on which a geometrical figure stands; also, the length of a base.

7. The point of beginning an act or operation.

8. A place on which a force depends for supplies.

9. A number (as 5 in 5⁷) that is raised to a power; especially, a number that when raised to a power equal to the logarithm of a number yields the number itself (the logarithm of 100 to ~ 10 is 2 since 10² = 100).

10. The number of units in a given digit's place of a number system that is required to give the numeral 1 in the next higher place (the decimal system uses a ~ of 10); also, such a system using an indicated base (convert from ~ 10 to ~ 2).

11. Any of the four stations at the corners of a baseball diamond.

12. To form or serve as a base for.

13. Establish.

14. Of inferior quality; debased, alloyed.

15. Contemptible, ignoble.

16. Menial, degrading.

17. Of little value.

outer medulla

DEFINITION:

See outer medulla of kidney.

transporter

DEFINITION:

A transport protein; often specifically a transport protein that after binding one to several molecules of substrate, undergoes a conformational change that moves only the substrate across the membrane. Different types facilitate movement with (symport) and against (antiport) concentration gradients.

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).

UT-A1

DEFINITION:

One of the urea transporters that is present only in the inner portion of the kidney. This urea transporter is important in the movement of urea from the urine into the tissue so that the kidney can move water and make a concentrated urine. (Klein)

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.

water channel

DEFINITION:

A channel in the plasma membrane of plant and animal cells that permits passage of water molecules; chemical substances such as vasopressin cause the opening of new channels and increase permeability.

NKCC2/BSC1

DEFINITION:

Sodium - potassium -2 chloride cotransporter, a transport protein that is responsible for moving sodium and chloride in and out of the cell. Works in conjunction with ROMK to maintain proper ion concentrations in cells. In the kidney it aids in making a concentrated urine. (Klein)

hypertension

DEFINITION:

Abnormally high blood pressure and especially arterial blood pressure.

aldosterone

DEFINITION:

The major mineralocorticoid hormone secreted by the adrenal cortex. It promotes the retention of sodium and bicarbonate, the excretion of potassium and hydrogen ions, and the secondary retention of water. Large excesses can invoke plasma volume expansion, edema, and hypertension. The secretion of aldosterone is stimulated by low plasma potassium concentration and angiotensin II.

norepinephrine

DEFINITION:

1. One of the naturally occurring catecholamines, a neurohormone released by the postganglionic adrenergic nerves and some brain neurons; it is a major neurotransmitter that acts on a- and ß₁-adrenergic receptors. It is also secreted by the adrenal medulla in response to splanchnic stimulation and is stored in the chromaffin granules. It is a powerful vasopressor and is released in the body usually in response to hypotension or stress. Called also noradrenaline .
2. A pharmaceutical preparation of the same substance, usually seen in the form of the bitartrate salt.

norepinephrine

DEFINITION:

1. One of the naturally occurring catecholamines, a neurohormone released by the postganglionic adrenergic nerves and some brain neurons; it is a major neurotransmitter that acts on a- and ß₁-adrenergic receptors. It is also secreted by the adrenal medulla in response to splanchnic stimulation and is stored in the chromaffin granules. It is a powerful vasopressor and is released in the body usually in response to hypotension or stress. Called also noradrenaline .
2. A pharmaceutical preparation of the same substance, usually seen in the form of the bitartrate salt.

urine volume

DEFINITION:

The measure of the quantity of urine, e.g., excreted from the kidneys.

sodium

DEFINITION:

A silver white soft waxy ductile element of the alkali metal group that occurs abundantly in nature in combined form and is very active chemically.

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.

UT-A1

DEFINITION:

One of the urea transporters that is present only in the inner portion of the kidney. This urea transporter is important in the movement of urea from the urine into the tissue so that the kidney can move water and make a concentrated urine. (Klein)

AQP2

DEFINITION:

Aquaporin-2.

NKCC2/BSC1

DEFINITION:

Sodium - potassium -2 chloride cotransporter, a transport protein that is responsible for moving sodium and chloride in and out of the cell. Works in conjunction with ROMK to maintain proper ion concentrations in cells. In the kidney it aids in making a concentrated urine. (Klein)

urine volume

DEFINITION:

The measure of the quantity of urine, e.g., excreted from the kidneys.

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.

UT-A1

DEFINITION:

One of the urea transporters that is present only in the inner portion of the kidney. This urea transporter is important in the movement of urea from the urine into the tissue so that the kidney can move water and make a concentrated urine. (Klein)

AQP2

DEFINITION:

Aquaporin-2.

proteins

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).

UT-A1

DEFINITION:

One of the urea transporters that is present only in the inner portion of the kidney. This urea transporter is important in the movement of urea from the urine into the tissue so that the kidney can move water and make a concentrated urine. (Klein)

AQP2

DEFINITION:

Aquaporin-2.

NKCC2/BSC1

DEFINITION:

Sodium - potassium -2 chloride cotransporter, a transport protein that is responsible for moving sodium and chloride in and out of the cell. Works in conjunction with ROMK to maintain proper ion concentrations in cells. In the kidney it aids in making a concentrated urine. (Klein)

UT-A1

DEFINITION:

One of the urea transporters that is present only in the inner portion of the kidney. This urea transporter is important in the movement of urea from the urine into the tissue so that the kidney can move water and make a concentrated urine. (Klein)

AQP2

DEFINITION:

Aquaporin-2.

diuresis

DEFINITION:

Increased excretion of urine.

natriuresis

DEFINITION:

The excretion of sodium in the urine.

norepinephrine

DEFINITION:

1. One of the naturally occurring catecholamines, a neurohormone released by the postganglionic adrenergic nerves and some brain neurons; it is a major neurotransmitter that acts on a- and ß₁-adrenergic receptors. It is also secreted by the adrenal medulla in response to splanchnic stimulation and is stored in the chromaffin granules. It is a powerful vasopressor and is released in the body usually in response to hypotension or stress. Called also noradrenaline .
2. A pharmaceutical preparation of the same substance, usually seen in the form of the bitartrate salt.

hypertension

DEFINITION:

Abnormally high blood pressure and especially arterial blood pressure.

aldosterone

DEFINITION:

The major mineralocorticoid hormone secreted by the adrenal cortex. It promotes the retention of sodium and bicarbonate, the excretion of potassium and hydrogen ions, and the secondary retention of water. Large excesses can invoke plasma volume expansion, edema, and hypertension. The secretion of aldosterone is stimulated by low plasma potassium concentration and angiotensin II.

permission

DEFINITION:

Formal consent; authorization.

malignant

DEFINITION:

1. Tending to become progressively worse and to result in death.
2. Having the properties of anaplasia, invasion, and metastasis; said of tumors.

hypertension

DEFINITION:

Abnormally high blood pressure and especially arterial blood pressure.

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 .

angiotensin II

DEFINITION:

An octapeptide hormone formed by the action of angiotensin-converting enzyme (peptidyl-dipeptidase A) on angiotensin I, chiefly in the lungs but also at other sites, including the blood vessel walls, uterus, and brain. It is a powerful vasopressor and stimulator of aldosterone secretion by the adrenal cortex, and it also functions as a neurotransmitter. Its vasopressor action raises blood pressure and diminishes fluid loss in the kidney by restricting blood flow.

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.

sodium

DEFINITION:

A silver white soft waxy ductile element of the alkali metal group that occurs abundantly in nature in combined form and is very active chemically.

transport protein

DEFINITION:

See under proteins .

UT-A1

DEFINITION:

One of the urea transporters that is present only in the inner portion of the kidney. This urea transporter is important in the movement of urea from the urine into the tissue so that the kidney can move water and make a concentrated urine. (Klein)

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.

NKCC2/BSC1

DEFINITION:

Sodium - potassium -2 chloride cotransporter, a transport protein that is responsible for moving sodium and chloride in and out of the cell. Works in conjunction with ROMK to maintain proper ion concentrations in cells. In the kidney it aids in making a concentrated urine. (Klein)

malignant

DEFINITION:

1. Tending to become progressively worse and to result in death.
2. Having the properties of anaplasia, invasion, and metastasis; said of tumors.

hypertension

DEFINITION:

Abnormally high blood pressure and especially arterial blood pressure.

urine

DEFINITION:

The fluid excreted by the kidneys, passed through the ureters, stored in the bladder, and discharged through the urethra. Urine, in health, has an amber color, a slight acid reaction, a peculiar odor, and a bitter, saline taste.

diuresis

DEFINITION:

Increased excretion of urine.

sodium

DEFINITION:

A silver white soft waxy ductile element of the alkali metal group that occurs abundantly in nature in combined form and is very active chemically.

urine

DEFINITION:

The fluid excreted by the kidneys, passed through the ureters, stored in the bladder, and discharged through the urethra. Urine, in health, has an amber color, a slight acid reaction, a peculiar odor, and a bitter, saline taste.

natriuresis

DEFINITION:

The excretion of sodium in the urine.

hypertension

DEFINITION:

Abnormally high blood pressure and especially arterial blood pressure.

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.

hypertension

DEFINITION:

Abnormally high blood pressure and especially arterial blood pressure.

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.

UT-A1

DEFINITION:

One of the urea transporters that is present only in the inner portion of the kidney. This urea transporter is important in the movement of urea from the urine into the tissue so that the kidney can move water and make a concentrated urine. (Klein)

AQP2

DEFINITION:

Aquaporin-2.

NKCC2/BSC1

DEFINITION:

Sodium - potassium -2 chloride cotransporter, a transport protein that is responsible for moving sodium and chloride in and out of the cell. Works in conjunction with ROMK to maintain proper ion concentrations in cells. In the kidney it aids in making a concentrated urine. (Klein)

hypertension

DEFINITION:

Abnormally high blood pressure and especially arterial blood pressure.

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 .

aldosterone

DEFINITION:

The major mineralocorticoid hormone secreted by the adrenal cortex. It promotes the retention of sodium and bicarbonate, the excretion of potassium and hydrogen ions, and the secondary retention of water. Large excesses can invoke plasma volume expansion, edema, and hypertension. The secretion of aldosterone is stimulated by low plasma potassium concentration and angiotensin II.

transport

DEFINITION:

The movement of materials in biological systems, particularly into and out of cells and across epithelial layers.

proteins

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).

diuresis

DEFINITION:

Increased excretion of urine.

natriuresis

DEFINITION:

The excretion of sodium in the urine.