Receptors Flashcards
(22 cards)
What is the role of hydroxyphenylalanine in the synthesis of dopamine?
Hydroxyphenylalanine is converted into dopa, which is then converted into dopamine.
This process is an essential part of catecholamine synthesis.
What inhibits the synthesis of dopamine?
Metyrosine inhibits the synthesis of dopamine.
Metyrosine acts as a competitive inhibitor.
How is dopamine stored in neurons?
Dopamine is stored in vesicles using carriers.
This storage mechanism is crucial for neurotransmitter release.
What inhibits the release of norepinephrine (NE)?
The release of norepinephrine is inhibited by reserpine.
Reserpine prevents the packaging of NE into vesicles.
What is the primary mechanism for terminating the action of norepinephrine?
Reuptake by the NE transporter is the primary mechanism for termination.
This process removes NE from the synaptic cleft.
Which drugs inhibit the reuptake of norepinephrine?
Tricyclic antidepressants and cocaine inhibit the reuptake of norepinephrine.
These drugs increase the availability of NE in the synaptic cleft.
What enzymes are involved in the metabolic transformation of norepinephrine?
MAO (Monoamine oxidase) and COMT (Catechol-O-methyltransferase) are involved in the metabolic transformation of norepinephrine.
These enzymes are critical for neurotransmitter catabolism.
What is the effect of calcium influx on adrenergic signaling?
Calcium influx increases PLC (Phospholipase C) and PKC (Protein Kinase C) activity.
This signaling pathway is important for various physiological responses.
What are the physiological effects of adrenergic signaling in blood vessels?
Adrenergic signaling causes vasoconstriction and contraction of sphincters.
This is crucial for regulating blood flow and pressure.
What does adrenergic stimulation do to glycogen metabolism?
Adrenergic stimulation promotes glycogenolysis and gluconeogenesis.
This enhances energy availability during stress responses.
What is the effect of beta-adrenergic receptors on cardiac function?
Beta-adrenergic receptors increase cardiac growth and contractility.
This is part of the body’s response to increased demand for blood flow.
Fill in the blank: Alpha 1 adrenergic receptors cause _______.
vasoconstriction
This action helps to increase blood pressure.
What neurotransmitter is synthesized by choline acetyltransferase?
Acetylcholine is synthesized by choline acetyltransferase.
This enzyme plays a key role in cholinergic signaling.
What inhibits the synthesis of acetylcholine?
Hemicholiniums inhibit the synthesis of acetylcholine.
These are competitive inhibitors of choline uptake.
What is the mechanism of acetylcholine release?
Acetylcholine is released through exocytosis.
This process is essential for neurotransmission at cholinergic synapses.
What inhibits the release of acetylcholine?
Botulinum toxin inhibits the release of acetylcholine.
This toxin prevents vesicle fusion with the membrane.
What are the two types of cholinergic receptors?
Muscarinic and nicotinic receptors are the two types of cholinergic receptors.
Each type has distinct physiological roles.
What is the role of acetylcholinesterase?
Acetylcholinesterase terminates the action of acetylcholine by hydrolyzing it.
This enzyme is crucial for preventing continuous stimulation of receptors.
Fill in the blank: M2 receptors cause a _______ in heart rate.
decrease
This is known as a negative chronotropic effect.
What is the effect of G-protein stimulation in the neuromuscular junction?
G-protein stimulation leads to skeletal muscle contraction.
This is mediated by depolarization of the muscle membrane.
What is the effect of beta-2 adrenergic receptors on the uterus?
Beta-2 adrenergic receptors cause uterine relaxation.
This is important during pregnancy and labor.
What is the role of Gq protein in adrenergic signaling?
Gq protein activates phospholipase C, leading to increased intracellular calcium.
This pathway is important for smooth muscle contraction.
