Receptor Theory (Owen) Flashcards
How do most drugs work?
By interacting with endogenous proteins.
What can drugs do to endogenous proteins?
Antagonize, block, or inhibit endogenous proteins.
Activate endogenous proteins.
What is pharmacology?
The study of what drugs do and how they do it. This includes interactions between drugs and body constituents at any level of organization.
A knowledge of pharmacology is essential for using drugs ______ and ______as therapy
…..safely…..effectively…..
What is a drug?
Any chemical compound that may be used on or administered to humans or animals as an aid in the diagnosis, treatment, or prevention of disease or other abnormal condition for the relief of pain or suffering, or to control/improve any physiological pathological condition.
How do drugs bring about change in biological functions?
Through their chemical actions.
What is a receptor, in terms of pharmacology?
A macromolecular component of the organism that binds the drug and initiates the drug’s effect.
Describe what you’d expect to find as a receptor.
Proteins that have undergone various post-translational modifications such as covalent attachments of carbohydrates, lipids, and phosphates.
How do some drugs antagonize, block, or inhibit endogenous proteins?
They act as: Antagonists of cell surface receptors Antagonists of nuclear receptors Enzyme inhibitors Ion channel blockers Transport inhibitors Inhibitors of signal transduction proteins
Why do cell surface receptors exist?
To transmit chemical signals from the outside to the inside of the cell.
What is a receptor antagonist?
A drug that “antagonizes” or “blocks” the receptor.
How might a drug prevent a response involving cell surface receptors?
The drug can bind the cell surface receptor without activating a receptor to trigger a response. It can also, by virtue of binding, prevent the endogenous chemical from binding the receptor, also preventing it from triggering a response.
What kind of cell surface receptor drug is used for angina, myocardial infarction, heart failure, high blood pressure, and performance anxiety?
Beta-adrenoreceptor blockers
How do beta-adrenoreceptor blockers work?
Via beta-blocking - they decrease the force of heart contractions so that the heart works less. Blocking the Beta1 by this Beta1Beta2 drug leads to less renin.
What is an example of a beta-adrenoreceptor blocker?
Propranolol
What is a nuclear receptor?
A receptor that exists in the intracellular compartment and upon activation binds to regulator regions in the DNA and modulates gene expression.
Some drugs bind to _____ _____, yet do not activate the receptors to translocate to the nucleus to bind _____ and alter _____ ______.
…..nuclear receptors…..DNA…..gene expresssion.
When nuclear receptors bind the drug molecule, the _____ ______ cannot bind to the receptor and thus cannot ______ ______ ______.
…..endogenous chemical…..alter gene expression.
What kind of nuclear receptor drug is used for prevention and treatment of breast cancer?
Estrogen receptor antagonists
What is an example of estrogen receptor antagonists?
Tamoxifen
How do drugs work by blocking ion channels?
Some drugs bind to ion channels and physically block cell membrane pores or cause an allosteric change that closes the pore.
Changes in the _____ concentration of ions mediate the effects of inhibitors of ion channels.
…..intracellular…..
What kind of drug that blocks ion channels is used for angina and high blood pressure?
Calcium channel blockers (CCBs)
What is an example of CCBs?
Diltiazem
How do drugs work by inhibiting enzymes?
Some drugs bind to enzymes and inhibit enzymatic activity, preventing the catalysis of biosynthesis of products from substrates. Loss of product due to enzyme inhibition mediates the effects of enzyme inhibitors.
What kind of drug that inhibits enzymes is used for pain relief, especially due to arthritis?
Cyclooxygenase inhibitors
What is an example of cyclooxygenase inhibitors?
Aspirin, Ibuprofen
What do cyclooxygenase inhibitors affect?
Prostaglandin synthesis
How do drugs work by inhibiting transporters?
Some drugs bind to transporters, which bind to and shuttle membrane-impermeable solutes across the cell membrane, and cause allosteric changes that prevent proper functioning of the transporters.
Changes in the _____ concentration of specific solutes mediate the effects of inhibitors of transporters.
…..intracellular…..
What kind of drug that inhibits transporters is used for the treatment of depression?
Selective serotonin reuptake inhibitors (SSRIs)
What is an example of SSRIs?
Fluoxetine
How do drugs work by inhibiting signal transduction proteins?
Some drugs bind to and inhibit key signal transduction proteins, which transmit a chemical signal from a receptor to the final biological target.
Inhibition of key signal transduction proteins may _____ or ______ the signal transduction pathway, ______ the effects of the drug.
…..block…..augment…..mediates…..
What kind of drug that inhibits signal transduction proteins is used for erectile dysfunction? What does it do?
Type 5 Phosphodiesterase Inhibitors - enables more vasodilation of penis
What is an example of Type 5 Phosphodiesterase Inhibitors?
Sildenafil
In what ways do some drugs activate endogenous proteins?
Agonists of cell surface receptors
Agonists of nuclear receptors
Enzyme activators
Ion channel openers
How do drugs work by activating cell surface receptors?
Cell surface receptors exist to transmit chemical signals from the outside to the inside of the cell. Some drugs, receptor agonists, bind to these receptors and trigger a response.
What kind of signal is the receptor drug agonist?
Some drug agonists are endogenous chemical signals whereas others mimic endogenous chemical signals.
What kind of drug that activates cell surface receptors is used for nasal congestion?
Alpha1-adrenoreceptor agonists
What is an example of alpha1-adrenoreceptor agonists?
Phenylephrine
How do drugs work by activating nuclear receptors?
Nuclear receptors exist to mediate the effects of intracellular, endogenous chemicals on gene expression. Some drugs, receptor agonists, bind to these receptors and trigger a response.
What kind of drug that activates nuclear receptors is used for hormone replacement therapy in postmenopausal women?
Estrogen receptor agonist
What is an example of an estrogen receptor agonist?
Conjugated equine estrogens
How do drugs work by activating enzymes?
Some drugs bind to enzymes and increase their enzymatic activity. Increased biosynthesis of product mediates the effects of enzyme activators.
What kind of drug activates enzymes? What is it used for?
Reactivators of cholinesterase - used after poisoning with nerve gas or organophosphate pesticide
What is an example of cholinesterase?
Pralidoxime - gets rid of built-up acetylcholine
How do drugs work by opening ion channels?
Some drugs bind to ion channels and allosterically open the ion channel or allosterically render the channel more readily open by other endogenous channels.
What kind of drug opens ion channels?
Potassium channel openers
What is an example of potassium channel openers?
Minoxidil - used for hair regrowth
What kind of drug is a disrupter of structural proteins? What is it used for?
Vinca alkaloids - used for cancer
What are examples of Vinca Alkaloids?
Vincristine, vinblastine
What kind of drug is an enzyme? What is it used for?
Thrombolytic therapy - myocardial infarction
What is an example of thrombolytic therapy?
Alteplase
What kind of drug covalently links to macromolecules? What is it used for?
DNA alkylating agent - treatment of cancer
What kind of drug reacts chemically with small molecules? What is it used for?
Antacids - neutralize gastric acid
What drug is an example of a DNA alkylating agent?
Cyclophosphamide
What drug is an example of an antacid?
Various preparations containing Al(OH)3, Mg(OH)2, CaCO3
What kind of drug binds free molecules or atoms? What is it used for?
Chelating agents - used for heavy metal poisoning
What are examples of chelating agents?
Dimercaprol, penicillamine
What kinds of drugs are nutrients?
Vitamins, minerals, lipids, carbohydrates, aminoacids
What kind of drug exerts actions due to physical properties? What is it used for?
Osmotic diuretic - edema; prevents fluid from going back into the body
What is an example of an osmotic diuretic?
Mannitol
What kind of drug works via an antisense action?What is it used for?
Antisense deoxyoligonucleotides - used for CMV, retinitis in patients with AIDS
What is an example of an antisense deoxyoligonucleotide?
Fomiversen
What kinds of drugs are antigens?
Vaccines
What kind of drug has an an unknown mechanism of action? What is it used for?
Inhalation anesthetics - used for general anesthesia
What is an example of an inhalation anesthetic?
Isoflurane
