drugs and enzyme transporters Flashcards
What is an enzyme inhibitor?
A molecule that binds to an enzyme and decreases its activity by preventing the substrate from binding or the reaction from occurring.
What are the two types of enzyme inhibitors?
Irreversible inhibitors: Bind permanently, often through chemical reactions like covalent bonding.
Reversible inhibitors: Bind non-covalently and can be removed.
How do reversible inhibitors work?
They can bind to the enzyme, the enzyme-substrate complex, or both, depending on the type.
Can enzymes themselves be used as drugs?
Yes, some enzymes (e.g., clot-busting drugs) are used as therapeutic agents.
What do statins do?
Statins block a key step in the cholesterol production pathway to lower cholesterol levels.
What type of medications are statins?
Statins are lipid-lowering medications that reduce “bad cholesterol.”
Why are statins used?
To prevent cardiovascular disease and reduce the risk of heart-related death in high-risk individuals.
What is the role of the renin-angiotensin-aldosterone system (RAAS)?
It regulates blood pressure by increasing salt and water retention, which raises blood pressure.
What does ACE (angiotensin-converting enzyme) do in the RAAS?
ACE converts angiotensin I into angiotensin II, which increases blood pressure through vasoconstriction and stimulating aldosterone secretion.
How do ACE inhibitors help control blood pressure?
ACE inhibitors block the conversion of angiotensin I to angiotensin II, lowering blood pressure by reducing vasoconstriction and water retention.
How does ACE inhibition affect blood pressure?
ACE inhibitors reduce the production of angiotensin II, lowering blood pressure by decreasing vasoconstriction and water retention.
What is the role of angiotensin II in the body?
Angiotensin II increases blood pressure by causing blood vessel constriction and stimulating water and salt retention.
What was the improvement introduced with second-generation ACE inhibitors like Enalapril?
Enhanced effectiveness and bioavailability, making it a billion-dollar drug.
How does SARS-CoV-2 use ACE2?
SARS-CoV-2 binds to ACE2 on cell surfaces to enter and infect human cells.
What is the role of ACE inhibitors in the RAAS system?
ACE inhibitors block the production of angiotensin II, reducing blood pressure and preventing organ damage.
What do ARBs (angiotensin receptor blockers) do?
ARBs prevent angiotensin II from binding to its receptor, reducing inflammation, lung injury, and blood vessel leakage.
parkinsons signs
What causes Parkinson’s disease symptoms?
Degeneration of dopaminergic neurons in the nigrostriatal pathway.
Name key symptoms of Parkinson’s disease.
Hypokinesia, tremor at rest, muscle rigidity, motor inertia, cognitive impairment, and basal ganglia degeneration.
How does treatment for Parkinson’s disease work?
By using enzyme inhibitor drugs to increase dopamine levels in the brain.
Which brain pathway is affected in Parkinson’s disease?
The nigrostriatal pathway.
What is L-DOPA?
A precursor to dopamine synthesized from L-Tyrosine.
Why is L-DOPA important in Parkinson’s disease treatment?
It crosses the blood-brain barrier and is converted into dopamine to improve symptoms.
What enzyme converts L-DOPA into dopamine?
DOPA decarboxylase.
What is the blood-brain barrier (BBB)?
A selective barrier that separates circulating blood from the brain.
What does a peripheral DDC inhibitor do?
It blocks DOPA decarboxylase in the periphery to increase L-DOPA availability for the brain.
Why is Carbidopa used with L-DOPA?
To prevent dopamine formation in the periphery, ensuring more L-DOPA crosses the blood-brain barrier
What is the benefit of blocking DDC in the periphery?
It reduces peripheral side effects and increases dopamine production in the CNS.
What is the role of peripheral COMT inhibitors?
They block the enzyme Catechol-O-methyl transferase (COMT) in the periphery to prevent the breakdown of L-DOPA.
How do COMT inhibitors improve L-DOPA therapy?
By increasing the amount of L-DOPA available to cross the blood-brain barrier.
Name two peripheral COMT inhibitors.
Tolcapone and Entacapone.
What do central COMT inhibitors do?
They prevent the breakdown of dopamine in the CNS.
How do central COMT inhibitors benefit Parkinson’s patients?
By keeping dopamine levels high in the brain, they help improve motor symptoms.
Name a central COMT inhibitor.
Tolcapone
What is the role of MAO-B inhibitors?
They prevent the breakdown of dopamine in the CNS.
How do MAO-B inhibitors help in Parkinson’s disease?
By increasing dopamine availability, they help alleviate motor symptoms.
Name two examples of MAO-B inhibitors.
Selegiline and Rasagiline.
What is the role of central dopamine receptor agonists in Parkinson’s disease?
They directly activate dopamine receptors in the brain.
How do dopamine receptor agonists differ from enzyme inhibitors in Parkinson’s treatment?
They mimic dopamine by activating its receptors, whereas enzyme inhibitors alter dopamine breakdown or production.
Name examples of dopamine receptor agonists.
Bromocriptine, Pergolide, Pramipexole, Ropinirole, and Rotigotine.
What does the diagram illustrate about therapeutic options?
It shows that multiple treatments can target different steps in a pathway to achieve the desired outcome.
Why are multiple therapeutic options important in a pathway?
They provide flexibility to address different aspects of the disease mechanism, allowing for tailored treatments.
What is the common goal of treatments shown in the diagram?
To enhance dopamine activity or mimic its effects in the brain for symptom management.
What is passive transport?
Transport that does not require energy, including symporters (e.g., Na/K/2Cl) and ion channels (e.g., Na, Ca, K, Cl).
What is active transport?
Transport that requires energy from ATP, facilitated by ATP-ases like Na/K pumps or K/H pumps.
Name examples of passive transport mechanisms.
Symporters (e.g., Na/K/2Cl) and ion channels (e.g., Na, Ca, K, Cl).
What are ATP-ases used for?
They drive active transport processes such as Na/K and K/H exchanges.
What energy source does active transport use?
ATP, which is converted to ADP or AMP during the process.
What does active transport help cells obtain?
Ions, glucose, and amino acids.