l2 SAQ Inverse Agonists

Play an AI-generated podcast conversation about this lesson

What does the term 'Quantal Dose Response' describe?

The dose of a drug that produces a given effect in a population.

What are some examples of responses that can be seen over a range of doses?

Sleep/no sleep, pain/no pain.

What does the term 'ED50' stand for?

Effective Dose 50.

What can be derived from graphs of receptor activation responses?

Measures of potency and efficacy. Signup and view all the answers

How can drugs be compared and contrasted?

By analyzing measures of potency and efficacy. Signup and view all the answers

What is the relationship between drug concentration and contraction traces?

As the drug concentration increases, the contraction traces also increase. Signup and view all the answers

What is the relationship between drug concentration and response in terms of mm?

As the drug concentration increases, the response in mm also increases. Signup and view all the answers

What is the relationship between drug concentration and % maximal response?

As the drug concentration increases, the % maximal response also increases. Signup and view all the answers

What is the EC50 value for the dose-response curve?

The EC50 value is 2.88 x 10-8 M. Signup and view all the answers

What is the difference between potency and efficacy?

Potency refers to the concentration or dose required to produce a certain response, while efficacy refers to the maximum response that can be achieved. Signup and view all the answers

What is the nature of drug interactions?

Agonists and Antagonists Signup and view all the answers

How are drug effects measured?

Receptor occupancy, Names, Receptors, Ion channels, Enzymes, Transporters, Full, Partial, Inverse, Biased, Competitive, Noncompetitive, Kd and Bmax, Potency, Dose response, EC50 and Emax, Efficacy, Agonists and antagonists Signup and view all the answers

Describe the concepts of agonists and antagonists.

Agonists: Drugs that bind to a receptor and cause an effect. Antagonists: Drugs that prevent the agonist-induced activation of the receptor. Signup and view all the answers

Describe the concept of partial agonists.

Partial agonists are drugs that do not fully activate a receptor, even at high doses. Signup and view all the answers

Depict the effects of inverse agonists and biased agonists.

Inverse agonists: Drugs that bind to a receptor and cause the opposite effect of an agonist. Biased agonists: Drugs that selectively activate specific signaling pathways of a receptor. Signup and view all the answers

What are the two types of antagonists according to Rang and Dale's classification?

Competitive antagonists and non-competitive antagonists. Signup and view all the answers

What is the most common and most important type of reversible competitive antagonism?

Antagonist competes with agonist for receptor binding sites. Signup and view all the answers

What is the difference between reversible competitive antagonism and irreversible competitive antagonism?

Reversible competitive antagonism can be out-competed by adding extra agonist, while irreversible competitive antagonism stays bound and cannot be displaced. Signup and view all the answers

What is the difference between non-competitive antagonism and competitive antagonism?

Non-competitive antagonism blocks at some point other than the receptor binding site, while competitive antagonism occurs at the same binding site as the endogenous ligand. Signup and view all the answers

What are the two theories regarding the molecular basis of partial agonism?

<ol> <li>The partial agonist is a good fit for the receptor binding site, but less able to promote the receptor conformational change leading to transduction. 2. The receptor may be in an active and inactive state, and that partial agonists form complexes with both states, whereas full agonists preferentially bind the active form.</li> </ol> Signup and view all the answers

What is the definition of an inverse agonist?

An inverse agonist is a ligand that binds to receptors and reduces the fraction of them in an active conformation, producing biological effects opposite to those produced by an agonist. Signup and view all the answers

What is the difference between an inverse agonist and a competitive antagonist?

An inverse agonist reduces the activation of a constitutively active receptor, while a competitive antagonist simply blocks the receptor without further inactivating receptor activity beyond its baseline value. Signup and view all the answers

What is the classical idea of an agonist?

The classical idea of an agonist is that it activates the whole repertoire of signals following activation. Signup and view all the answers

What is the revised theory of receptor coupling?

The revised theory suggests that receptor coupling results in myriad configurations (states), and that a certain configuration may elicit a specific subset of signaling response. Signup and view all the answers

What are the key concepts of agonists and antagonists?

The key concepts include: 1. Receptor activation can be described with mathematical models. 2. Receptor activation is not linear with ligand binding. 3. Usually relatively low receptor occupancy is required to elicit relatively high response. 4. Receptor-mediated activity is affected by the inherent properties of the ligand, the number of receptors present, and the characteristics of the signal transduction machinery. Signup and view all the answers