A

Adrenergic: Pertaining to nerves that release the neurotransmitter norepinephrine/noradrenaline (e.g. adrenergic nerves, adrenergic response). An alternative U.S. useage also pertains to the receptors acted upon by noradrenaline, i.e. adrenergic receptors. The IUPHAR approved nomenclature for these receptors is 'adrenoceptor'. www.adrenoceptor.com!

Adrenoceptor: The receptors upon which the circulating catecholamines (adrenaline and noradrenaline) exert theri action.

Agonist: A drug which binds to a receptor and activates it, producing a pharmacological response (e.g. contraction, relaxation, secretion, enzyme activation, etc.).

Allosteric (Change): Alteration of a protein conformation resulting in alteration of function (e.g. non-competitive receptor inhibition).

Amino Acid: A component of every protein, in which up to 20 different amino acids are strung together into polymer chains.

Antagonist: A drug which attenuates the effects of an agonist. Antagonism can be competitive and reversible (i.e. it binds reversibly to a region of the receptor in common with the agonist.) or competitve and irreversible (i.e.antagonist binds covalently to the agonist binding site, and no amount of agonist can overcome the inhibition). Other types ofantagonism are non-competitive antagonism where the antagonist binds to an allosteric site on the receptor or an associated ion channel.

B

Blood Pressure: The hydrostatic force that blood exerts against the wall of a vessel.

Bronchoconstriction: Constriction of the smooth muscle in airways in the lungs due to exposure to irritant chemicals or to an immunological reaction involving release of inflammatory mediators.

C

Chromosome: A long, threadlike association of genes in the nucleus of all eukaryotic cells. Chromosomes consist of DNA and protein.

Clone: A lineage of genetically identical individuals.

Cloning vector: An agent used to transfer DNA in genetic engineering, such as a plasmid that moves recombinant DNA from a test tube back into a cell, or a virus that transfers recombinant DNA by infection.

Complementary DNA (cDNA): DNA that is identical to a native DNA containing a gene of interest, except that the cDNA lacks noncoding regions (introns) because it is synthesised in the laboratory using mRNA templates.

Concentration ratio: Concentration of agonist producing a defined response in the presence of an antagonist, divided by the concentration producing the same response in the absence of antagonist.

Cooperativity: An interaction of the constituent subunits of a protein causing a conformational change in one subunit to be transmitted to all others.

cyclic AMP (cAMP) (cyclic adenosine monophosphate): A small, ring shaped molecule that acts as achemical signal in slime molds, as an intracellular second messenger in vertebrate endocrine systems, and as a regulator of the lac operon.

Cytoplasm: The entire contents of the cell, exclusive of the nucleus, and bounded by the plasma membrane.