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.

protein kinase C

DEFINITION:

Any of a family of protein kinase isozymes, occurring in numerous tissues, that catalyze the phosphorylation of specific serine or threonine residues of a variety of intracellular proteins, altering their activities. The enzymes are activated via receptor binding by the hormones, growth factors, and other agents that cause increases in intracellular calcium and cleavage of phosphoinositides; some isozymes require calcium and phospholipid for activity, which is enhanced by diacylglycerol. The enzyme is involved in several types of cellular signal transduction and has been shown to play a role in platelet activation and in the inhibition of some peptide hormone receptors and to be a binding site for phorbol esters and other tumor promoters, as well as having numerous other roles and substrates, only some of which are known.

PKC

DEFINITION:

Protein kinase C.

isoenzyme

DEFINITION:

Isozyme.

expressed

DEFINITION:

1. Showing a detectable effect of a gene.

2. Made known; shown.

3. Squeezed out; extracted by pressing.

glomeruli

DEFINITION:

Plural of glomerulus.

cortical collecting duct

DEFINITION:

Also known as the "cortical collecting tubule," the more proximal parts of the renal tubule, lying within the cortex.

intercalated cells

DEFINITION:

Dark-colored cells in the renal collecting tubules that are responsible for acidification of the urine.

medullary collecting duct

DEFINITION:

The distal part of the renal tubule, including the loop of Henle, lying within the medulla. See also duct .

PKC

DEFINITION:

Protein kinase C.

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 .

PKC

DEFINITION:

Protein kinase C.

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.

metabolic

DEFINITION:

Pertaining to or of the nature of metabolism.

urinary

DEFINITION:

Pertaining to the urine; containing or secreting urine.

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).

creatinine

DEFINITION:

A white crystalline strongly basic compound excreted in the urine; measurements of excretion rates are used as diagnostic indicators of kidney function and muscle mass and can be used to simplify other clinical assays.

ratio

DEFINITION:

An expression of the quantity of one substance or entity in relation to that of another; the relationship between two quantities expressed as the quotient of one divided by the other.

PKC

DEFINITION:

Protein kinase C.

renal

DEFINITION:

Pertaining to the kidney.

albumin

DEFINITION:

1. Any protein that is soluble in water and moderately concentrated salt solutions and is coagulable by heat.

2. Serum albumin; the major plasma protein (approximately 60 percent of the total), which is responsible for much of the plasma colloidal osmotic pressure and serves as a transport protein carrying large organic anions, such as fatty acids, bilirubin, and many drugs, and also carrying certain hormones, such as cortisol and thyroxine, when their specific binding globulins are saturated. Albumin is synthesized in the liver. Low serum levels occur in protein malnutrition, active inflammation and serious hepatic and renal disease.

glomerular filtration rate

DEFINITION:

(GFR): The quantity of glomerular filtrate formed per unit time in all nephrons of both kidneys, equal to the inulin clearance; usually measured clinically by the endogenous creatinine clearance.

fractional

DEFINITION:

Pertaining to a portion of something larger.

renal

DEFINITION:

Pertaining to the kidney.

reabsorption

DEFINITION:

The act or process of absorbing again, as the selective absorption by the kidneys of substances (glucose, proteins, sodium, etc.) already secreted into the renal tubules, and their return to the circulating blood.

PKC

DEFINITION:

Protein kinase C.

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.

PKC

DEFINITION:

Protein kinase C.

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.

hypotonic

DEFINITION:

1. Denoting a solution which, when bathing body cells, causes a net flow of water across the semipermeable cell membrane into the cell.

2. Denoting a solution having less tonicity than another solution, e.g., the blood, with which it is compared.

3. Exhibiting hypotonia.

PKC

DEFINITION:

Protein kinase C.

oral

DEFINITION:

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

water loading

DEFINITION:

The administration of sufficient quantities of water to test the subject's ability to metabolize it.

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).

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.

antagonist

DEFINITION:

1. A muscle whose action is the direct opposite of that of another muscle.

2. 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 of substances that could elicit such responses.

3. A tooth in one jaw that articulates with a tooth in the other jaw.

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.

PKC

DEFINITION:

Protein kinase C.

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 .

basal

DEFINITION:

Pertaining to or situated near a base.

PKC

DEFINITION:

Protein kinase C.

renal

DEFINITION:

Pertaining to the kidney.

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).

medullary collecting duct

DEFINITION:

The distal part of the renal tubule, including the loop of Henle, lying within the medulla. See also duct .

urinary concentration

DEFINITION:

The increase in strength of urine by evaporation.

PKC

DEFINITION:

Protein kinase C.

PKC

DEFINITION:

Protein kinase C.

medullary collecting duct

DEFINITION:

The distal part of the renal tubule, including the loop of Henle, lying within the medulla. See also duct .

PKC

DEFINITION:

Protein kinase C.

isoenzymes

DEFINITION:

Isozymes.

permission

DEFINITION:

Formal consent; authorization.