Extracellular region consists of one or more binding sites, complementary in shape to specific molecule(s)

Transmembrane region gives the common name of 'serpentine receptors', polypeptide chain weaves across membrane, consisting of hydrophobic amino acids due to lipid tails of phospholipids.

Intracellular region consists of either the N- or C-terminus as with the extracellular. Does/not ever contain lipid/acrbohydrate derivatives.

Index of the maximal response any drug can elicit as a result of it receptor interactions. Between 1.0-0

Therefore ability of drug to produce a desired therapeutic effect. 

Intrinsic property, no, depends upon the specific receptor which interacts with and which causes effects via. 

Theoretically related to affinity:

• The amount of a drug which is required to elicit a response --> May not require AR complexes at every available receptor [Rt] in order to transduce a signal which is sufficiently "strong" to cause physiological response. 
• -->Energetically efficient for small hormone molecules to have capability to produce a relatively large response from small concentrations
• Therefore determines the dosage that needs to be administered.

Is patient-dependent, due to  physiological constitutive basal level of signal transduction mediated, as a function of the R*, which is dependent upon gene expression

Common units: micromoles ug (10-6)g nanomoles ng (10-9)g

administered to person of "blah" mass

dose/amount per unit volume

Common units:

micro molar uM (10-6)MolesL-1

nanomolar nM (10-9)MolesL-1

Shifts position of equilibrium so that protein receptor is within inatctivated-R conformation. By selectivly binding and stabilising it.

-Ligands selective for R* (active) conformations

DRUG EXAMPLE: male LH mutant receptor

Used in cases where mutant receptors result in a higher basal level of physiological processes occurring

--> without stimulation by hormone/extracellular signal

(regulated secretion/synthesis--> temporal or spatial is lost)

Have efficacy 1.0 -->

Do have potential to produce a maximal response from AR,

(drug-receptor complex)

POTENCY--> is reduced, because the concentration of agonist required /dosage administered, to elicit a response is higher than with no antagonist present within system/patient

EFFICACY--> unaffected, still reached when [agonist]:[antagonist] ratio allows agonist to bind more frquentlya nd cause signal transduction

• any drug which produces response by binding to receptor
• Can be either an increase or decrease in activity
• Less common form of treatment, more possibility of malfunction

POTENCY --> unaffected, intrinsic property of the agonist, but apparent potency decreases, therefore EC/ED50 decreased.

Higher doses required to reach same threshold level of transduction to eleict a tissue response

EFFICACY --> decreased as the competitive anatgonist conc. increases.

Cannot reach maximum response level (transduction limited by receptor availability) 

What would the follow changes indicate about the adjuvent drug's effect on the log-dose agonist respose curve upon increased serial concentrations added?

1. A parallel shift  to right
2. same max. response reached

Indicates a competitive reversible anatgonist

1. proves anatgonistic/blocking effects upon agonst activity(at certain receptor)

2. No change in efficacy at higher agonist concentration, proves that the anatgonist reversibly binds to receptor. Can be outcompeted by agonist, chance of agonist binding higher.

• Some competitive irreversible antagonists producing a parallel shift in agonist dose-response curve at low [anatgonist]

--> Alike to effect of irreversible anatgonist

Where antagonist is bound to receptor reserve: density of [Rt] not required to be in [AR] for threshold level of signal transduction to elict a tissue response.

• At higher concentrations when anatgonist also binds to >Rreserve, the maximum response level of tissue isn't reached.