Flashcards in Introduction to Pharmacology and Toxicology- Transporters as targets Deck (21):
What membranes does passive diffusion require?
Doesn't require any proteins
Example: glycerol- no membrane needed to diffuse across
What membranes does facilitated diffusion require?
Requires a protein, substance flows along concentration gradient
Example: Glucose transporters- to and from the brain- blood brain barrier
What membranes does Primary Active Transport require?
Requires a protein which a substance flows against concentration gradient
This requires energy to provide directly by ATP hydrolysis- Na+K+ATPase- transfers multiple ions
What membranes does Secondary Active Transport require?
Requires a protein where substance flows against concentration gradient
Energy required provided indirectly by ATP hydrolysis
Gradient of ion used to couple transport (usually sodium)
Can be simper or antiport mechanism
Can go forward or backward
What does it mean by facilitated transport is saturated?
Can only have as much substrate on the extracellular domain, cannot transport anymore of that ion or that molecule due to the levels of substrate concentration
Need active transport to solve the issue
What are the different classes of pumps?
1. P class pumps
2. V class pumps
3. F class pumps
4. ABC (ATP binding cassete)
What is the function of the P class pump work and what does it transport?
1. Transports all types of ion- phosphorylation event occurs
2. Only specific to one or two kinds of ions
3. Transport more than one type of ion at a time
4. Example: Na+/K+ pump
What is the function of the V class Pump and what does it transport?
1. Only transports protons
2. Structure is very different to P class
3. They are normally used to maintain a low pH in vacuoles and Lysosomes
What is the function of the F class pump and what does it transport?
1. Only transports protons down its electrochemical gradient, using the movement of protons to power ATP synthesis
2. Structure is very different to F class
3. Example: ATP synthase pump found in mitochondria
What is the function of the ABC (ATP Binding Cassette) and what does it transport?
1. Superfamily of pumps that can transport all kinds of molecules- including polysaccharides and proteins
2. All pumps contain two transmembrane domains and two cytosolic domains which bind ATP
3. Example: CFTR pump in the membrane of epithelial cells can cause cystic fibrosis if mutated
What are the different 3 transporter families?
1. Ion transporters and pumps- sodium potassium ATPase
2. Metabolite transporters
3. Neurotransmitter Transporters
- plasma membranes
What are the metabolite transporters and give an example?
1. Drug super family of transporters
2. Chloroquine Resistance Transporter (PfCRT) Family:
some malarial parasites have developed resistance to chloroquine through mutations in this transporter
What are the Neurotransmitter transporters I?
1. Vesicular inhibitory amino acid transporter
2. Vesicular excitatory amino acid transporter
3. Vesicular amine transporters
Used for scientific research for things to be packed into vesicles and released into the synaptic terminal
Packaging neurotransmitter for release
What are the neurotransmitter transporters II used for? And give some examples
In the plasma membrane that's tailored to specific transporters
NET- Noradrenaline transporter
DAT- dopamine transporters
EAAT- Excitatory amino acid transporters
GAT- GABA transporters
GlyT- Glycine transporters
How does the pre synaptic terminal and post synaptic terminal work?
The presynaptic terminal sends a signal of serotonin containing vesicle through the serotonin transporter/5-HT transporter
How does the 5-HT+ transporter works?
For one K+, one Na+ and Cl- comes along
What does serotonin do?
Creates happy thoughts
What does citalopram do?
1. Blocks serotonin reuptake (member of the SSRIs)
2. More increase of serotonin signal so it stays longer
3. Indication: Depressive illness, panic disorder
What does the dexamfetamine do?
1. Blocks monoamine transporters (including the dopamine family)
2. Stimulant that increase the levels of central nervous system stimulate
3. Indication: narcolepsy, refractory attention deficit, hyperactivity disorder
What does cocaine do?
Bind to the dopamine transporter and acts as an antagonist