receptors

DEFINITION:

See definitions under "receptor."

homologous

DEFINITION:

1. Corresponding in structure, position, origin, etc., as (a) the feathers of a bird and the scales of a fish, (b) antigen and its specific antibody, (c) allelic chromosomes.

2. Allogeneic.

3. Pertaining to an antibody and the antigen that elicited its production.

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.

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.

superfamily

DEFINITION:

1. A taxonomic category sometimes established, subordinate to an order and superior to a family.
2. Any of a group of proteins having similarities such as areas of structural homology and believed to descend from the same ancestral gene; e.g., integrins or immunoglobulins.

genes

DEFINITION:

In the singular: 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.

receptors

DEFINITION:

See definitions under "receptor."

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.

series

DEFINITION:

1. A group or succession of objects or substances arranged in regular order or forming a kind of chain.
2. Pertaining to electrical circuit components connected "in series" so that the current flow goes through each component without branching; applied by extension to any similar series circuit, e.g., the pulmonary and systemic circulations.
3. A taxonomic category of fungi falling between a subphylum and an order and based on the type of ascus the organism possesses.

monocytic series - The succession of developing cells that ultimately culminates in the monocyte; after the colony-forming unit-granulocyte-macrophage , the stages in order of maturity are the monoblast , promonocyte , and the mature monocyte .

mutants

DEFINITION:

1. Genes or organisms that have undergone genetic mutation.

constructed

DEFINITION:

Built, made.

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.

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.

signal transduction

DEFINITION:

The process by which a cell receives and acts on some external chemical or physical signal, such as a hormone, including receiving the information at specific receptors in the plasma membrane, conveying the signal across the plasma membrane into the cell, and subsequently inducing an intracellular chain of other signalling molecules, thereby stimulating a specific cellular response.

properties

DEFINITION:

Properties are characteristic qualities, abilities, capabilities, or functions.

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 .

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 .

receptors

DEFINITION:

See definitions under "receptor."

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 .

mutants

DEFINITION:

1. Genes or organisms that have undergone genetic mutation.

mediate

DEFINITION:

Indirect; accomplished by the aid of an intervening medium.

intracellular cAMP

DEFINITION:

Cyclic adenosine monophosphate within a cell.

adenylyl cyclase

DEFINITION:

A membrane-bound enzyme that catalyzes the formation of cyclic AMP from ATP. An important component of some intracellular signaling pathways.

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 .

mutant

DEFINITION:

1. A gene or organism that has undergone genetic mutation.

constructed

DEFINITION:

Built, made.

amino acids

DEFINITION:

See definition for "amino acid."

ARG

DEFINITION:

Abbreviation for autoradiography.

ARG

DEFINITION:

Abbreviation for autoradiography.

intracellular

DEFINITION:

Situated or occurring within a cell or cells.

corresponding

DEFINITION:

Agreeing or conforming.

amino acids

DEFINITION:

See definition for "amino acid."

ARG

DEFINITION:

Abbreviation for autoradiography.

ARG

DEFINITION:

Abbreviation for autoradiography.

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.

gastrin

DEFINITION:

Any of several polypeptide hormones released from peptidergic fibers in the vagus nerve and from G cells in the pyloric glands in the gastric antrum. Forms include little gastrins (G₁₇), with chain lengths of 17 amino acids, big gastrins (G₃₄), and minigastrins (G₁₄). Gastrin stimulates secretion of gastric acid (causing contraction of the lower esophageal sphincter and modifying gastric and esophageal motility), increases growth of acid-secreting mucosa cells, and weakly stimulates secretion of pancreatic enzymes and gallbladder contraction.

calcium

DEFINITION:

A silvery yellow metal, the basic element of lime. Symbol, Ca; atomic number, 20; atomic weight, 40.08. It is found in nearly all organized tissues, being the most abundant mineral in the body. In combination with phosphorus it forms calcium phosphate, the dense, hard material of the teeth and bones. It is an essential dietary element, a constant blood calcium level being essential for the maintenance of the normal heartbeat, and for the normal functioning of nerves and muscles. It also plays a role in multiple phases of blood coagulation and in many enzymatic processes.

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 .

positive

DEFINITION:

Having a value greater than zero; indicating existence or presence of a condition, organism, etc., as chromatin positive or Wassermann positive; characterized by affirmation or cooperation.

cAMP

DEFINITION:

Cyclic AMP (cyclic adenosine monophosphate).

gastrin

DEFINITION:

Any of several polypeptide hormones released from peptidergic fibers in the vagus nerve and from G cells in the pyloric glands in the gastric antrum. Forms include little gastrins (G₁₇), with chain lengths of 17 amino acids, big gastrins (G₃₄), and minigastrins (G₁₄). Gastrin stimulates secretion of gastric acid (causing contraction of the lower esophageal sphincter and modifying gastric and esophageal motility), increases growth of acid-secreting mucosa cells, and weakly stimulates secretion of pancreatic enzymes and gallbladder contraction.

intracellular

DEFINITION:

Situated or occurring within a cell or cells.

coupling

DEFINITION:

1. The joining together of two things.

2. In genetics, the occurrence on the same chromosome in a double heterozygote of the two mutant alleles of interest.

3. In cardiology, the serial occurrence of a normal heart beat followed closely by a premature beat.

activation

DEFINITION:

1. The act or process of rendering active.

2. The transformation of a proenzyme into an active enzyme by the action of a kinase or another proenzyme.

3. Gain in the purifying of sewage by means of activated sludge.

4. The process by which the central nervous system is stimulated into activity through the mediation of the reticular activating system.

5. The deliberate induction of a pattern of electrical activity in the brain in electroencephalography.

permission

DEFINITION:

Formal consent; authorization.