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Flashcards in Essential Pharmacology Deck (12):

What are the basic functions of receptors?

- enable specificity
- evoke an appropriate response


What is a receptor?

A protein that recognises a specific compound or molecule
- this can result in the triggering of a massive variety of effects
- or can in some cases inhibit the effects of the proteins and chemicals


What do agonists do?

Mimic the normal effect of a receptor


What do antagonists do?

Block the normal action of a receptor


Describe the relationship between agonist concentration and effect

Increasing conc. of agonist will mean more receptors are occupied by it so the effect increases
- this only works up to a certain point where all of the receptors become saturated and there are no longer free ones for the agonist to bind to


What is affinity?

The strength of the chemical attraction between the drug and receptor


What is the efficacy of an agonist?

How good an agonist is at activating the particular receptor


What are the four types of membrane receptors?

- receptors that act as ion channels
- receptors with intrinsic enzyme activity
- receptors that interact with JAK kinases
- receptors that interact with G-proteins


What is the largest family of membrane receptors?

G-protein receptors


What happens when G-protein receptors are couples to Adenylyl Cyclase?

- increases/decreases conc. of cAMP
- activates/inhibits PKA


What happens when G-protein receptors are coupled to Phospholipase C?

- produces diacylglycerol and inositol triphosphate
- activates PKC and releases internal Ca2+ stores


What are the sources on intracellular calcium?

- from internal stores via calcium triggered release from endoplasmic reticulum
- from outside the cell via ligand-gated or voltage-gated channels
- via inhibition of Ca2+ transport out of the cell