L5 Intro to Pharmacology

Question 1

Define ‘drug’

Answer 1

A chemical substance of known structure, other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect

Question 2

Define ‘pharmacology’

Answer 2

The study of mechanisms by which drugs affect the function of living systems

Question 3

What are bioassays?

Answer 3

Bioassays are analytical methods used to determine the potency or effect of a substance by observing its impact on living organisms or their components

Question 4

What are the 3 fundamental principles of pharmacology?

Answer 4

• Drug action must be explicable in terms of conventional chemical interactions between drugs and tissues
• Drug molecules must be ‘bound’ to particular constituents of cells and tissues in order to produce an effect
• Drug molecules must exert some chemical influence on one or more constituents of cells in order to produce a pharmacological response

Question 5

What are the 4 classes of proteins commonly targeted by drugs?

Answer 5

Enzymes
Transporters
Ion Channels
Receptors

Question 6

How do most drugs exert their actions?

Answer 6

Most drugs exert their actions by binding to proteins

Question 7

Define the term ‘ligand’

Answer 7

Any molecule that binds to the receptor, it may be an agonist or an antagonist

Question 8

Define the term ‘agonists’

Answer 8

Drugs or chemical mediators that bind to a receptor producing a response are referred to as agonists

Question 9

Define the term ‘antagonist’

Answer 9

Drugs that prevent or inhibit the response of an agonist. They may bind to the receptor but DO NOT elicit a response

Question 10

How do drugs cause side effects?

Answer 10

Drugs lack specificity. Many receptors are found in more than one organ.
Drugs will bind to receptors wherever they are located which can lead to side effects

Question 11

Within the receptor family, we often find subtypes with distinct subunit compositions. How can this be exploited to develop drugs with selective effects?

Answer 11

Variation in receptor subtype and localisation gives rise to specificity which may be exploited by drugs to produce desirable therapeutic effects.

Question 12

What is the abbreviation for CAR?

Answer 12

Chimeric antigen receptor

Engineered receptor designed to recognise cancer cell

Question 13

What do CAR T immunotherapy do?

Answer 13

It’s uses contact-dependent signalling to kill cancer cells.

Question 14

How does CAR T immunotherapy work?

Answer 14

1) Collect T cells from your blood
2) Change the T cells in the lab to become CAR T-cells
3) CAR T- cells multiply in the lab
4) A drip of CAR T-cells into your blood stream
5) The CAR T-cells find and attack the cancer cell

Question 15

What are mast cells?

Answer 15

They detect allergens and are located under the skin. They are receptors

Question 16

Can you give one example of the paracrine signalling to be affected by drugs that act on receptors?

Answer 16

Histamine (mediator) which act locally to produce vasodilation and activate neurones are involved in itchiness

Question 17

How can paracrine signalling be affected by drugs that are acting on enzymes?

Answer 17

• Drugs - Paracetamol can target enzymes which synthesis the mediators
• Nitric Oxide causes relaxation of smooth muscle cells and vasodilation however Viagra inhibits the enzyme responsible for the breakdown of cGMP, prolonging NO action

Question 18

What are the 4 classes of proteins that are commonly targeted by drugs?

Answer 18

Enzymes
Transporters
Ion channels
Receptors

Question 19

Drugs can target ion channels involved in regulating neurotransmission. How?

Answer 19

Drugs can block voltage-gated Na+ channels
- prevent action potential generation
- used as local anaesthetics
- e.g. lidocaine (lignocaine)

Question 20

Drugs can target the machinery involved in the release of neurotransmitters. Example?

Answer 20

Botulinum toxin (BoTox) produced by bacteria cleaves proteins which are part of the synaptic machinery

Question 21

Drugs can target transporters found on the cell membrane and vesicle membrane. An example?

Answer 21

Amphetamines indirectly increase noradrenaline release by displacing it from its vesicles

Question 22

Therapeutic drugs can also target transporters required for neurotransmission. How? Example?

Answer 22

• It prevents the reuptake of neurotransmitters
• Used to alleviate the symptoms of neurological conditions
• e.g. Fluoxetine (Prozac) blocks 5HT reuptake and is an antidepressant and anxiolytic

Question 23

Neuronal signalling can be affected by drugs acting on receptors. How?

Answer 23

Receptors at the post-synaptic terminal can be:
- Activated by agonists
Inhibited by antagonists