Topic 84 - Catecholamines Flashcards
1
Q
Words to include general
A
- Adrenal medulla
- Granules
- Chromogranin
- ATP
- EC space
- Exocytosis
- Alpha receptors
- Beta receptors
- Sympathetic-adrenal system
- Physical output
- Epinephrine / adrenaline
- Muscular activity
- Cold
- Blood pressure (↓)
- Norepinephrine / noradrenaline
- Hypoxia
- Pain
- Anxiety
2
Q
Words to include in synthesis of catecholamines
A
- Precursors
- Granules
- Antiport protein
- Hydrogen concentration gradient
- ATPase pump
- DBH (Dopamine-Beta-Hydroxylase)
- Granular norepinephrine
- Cytoplasm
- PNMT (Phenylethanolamine-ortho-methyltransferase)
- Chromogranin
- Peptides
- Somatostatin
- Enkephalin
- NPY (neuropeptide Y)
- Adrenal gland
- Sympathetic terminals
- Sympathetic effects
- Peptidergic co-transmission
- Phenylalanine
- Phe-hydroxylase
- Tyrosine
- Thy-hydroxylase
- DOPA
- Decarboxylase
- Dopamine
- Dopamine-beta hydroxylase DBH
- Norepinephrine
- Phenylethanolamine-ortho-methyltransferase PNMT
- Epinephrine
- DBH
- Granules
- PNMT
- Cytoplasm
- Amine precursor
- H+ ATPase
3
Q
Words to include in inactivation of hormones
A
- Degradation
- MAO (monoamine oxidase)
- Mitochondria
- COMT (Cathecholamine-O-methyltranspherase)
- Cytoplasm
- Plasma metabolites
- MAO (monoamine oxidase)
- Inactivation - reuptake
- Presynaptic alpha-receptors
- Alpha-2 receptor
- Reuptake
- Postsynaptic alpha-receptors
- Alpha-1 receptor
- Electrical effect
- Metabolic effect
4
Q
Words to include in receptors
A
- IC signaling
- Catecholamine receptors
- G protein dependent cAMP system
- General effects
- Alpha receptor effects
- Alpha-1
- Smooth muscle contraction
- Glycogenolysis
- Sympathetic synaptic transduction
- PLC
- Alpha-2
- CNS
- AC
- Alpha-1
- Beta receptor effects
- Beta-1
- Heart
- Adipose cells
- AC
- Beta-2
- Smooth muscle relaxation
- Metabolism (↑)
- AC
- Beta-1
- Alpha receptor effects
- Circulation effects
- Sympathetic nervous system
- sympathetic activation
- Vasoconstriction
- BP (Binding Protein)
- Intermediary metabolism effects
- Oxygen consumptrion (BMR) (↑)
- Hepatic glygogenolysis
- Respiration requency
- Calorigenic effect
- Cardiac output (↑)
- Respiration (↑)
- Carbohydrate metabolism
- Blood glucose
- Lipid metabolism
- Free fatty acid (↑)
- Oxygen consumptrion (BMR) (↑)
5
Q
Words to incude in alarm reaction
A
- “Fight or flight” reflex
- Adrenal medulla
- Cannon’s reaction / “alarm reaction#
6
Q
Words to include in regulation of adrenal cortex
A
- Sympathetic nervous system
- Indirectly
- Directily
- Hypoglycemia
- Direct stimulus
- Alarm reaction
- Receptor regulation
- Complex
7
Q
What are cathecholamines?
A
- Hormones of the adrenal medulla
- Epinephrine / adrenaline
- Norepinephrine / noradrenaline
- Synthesized hormone molecules are stored in granules
- Contain chromogranin and ATP
- Act on alpha and beta receptors
8
Q
General about epinephrine / adrenaline
A
- Hormone of fighting
- Produced by effects of:
- Muscle activity
- Cold
- Decreased blood pressure
9
Q
General about norepinephrine / noradrenaline
A
- Hormone of aggressive behavior
- Produced by effects of:
- Hypoxia
- Pain
- Emotional anxiety
10
Q
Synthesis of catecholamines
Steps
A
-
Precursors enter the granules by an antiport protein
- The antiport protein utilizes a hydrogen concentration gradient maintained by ATPase pump
-
DBH (Dopamine-Beta-Hydroxylase) is present in the granules
- Results in granular norepinephrine
- Released into the cytoplasm and converted to epinephrine
-
Norepinephrine and epinephrine are stored in granules until liberation
-
Chromagranin stores the final products:
- Epinephrine
- Norepinephrine
-
Peptides:
- Somatosin
- Enkephalin
- NPY (Neuropeptide Y)
-
Chromagranin stores the final products:
- These modulators are released from adrenal gland and influence sympathetic effects
- Called peptidergic co-transmission
11
Q
Inactivation of hormones
A
- Suspension of hormonal effects is made possible by:
-
Degradation of hormones
-
MAO (monoamine oxidase)
- Mitochondria
-
COMT (catecholamine-O-methyltranspherase)
- Cytoplasm
- Plasma metabolites
-
MAO (monoamine oxidase)
- Reuptake of hormones liberated by neurons
-
Degradation of hormones
Figure: inactivation-reuptake
12
Q
What does catecholamine exerts their effects on?
A
- Alpha-1 and alpha-2 receptors
- Beta-1 and beta-2 receptors
- Circulation
- Smooth muscles
- Intermediary metabolism
- Different organs
13
Q
Receptors
Which receptors does epinephrine and norepinephrine act on?
A
-
Norepinephrine stimulates mainly:
- Alpha-1 receptors
- Beta-1 receptors
-
Epinephrine stimulates mainly:
- Beta-2 receptors
- Alpha-1 receptors
14
Q
Receptor
IC signaling - How does catecholamine receptors exert effect
A
Catecholamine receptors exert effect by G protein dependent cAMP system
15
Q
Receptors
General effect of catecholamines on alpha receptor
A
-
Alpha-1 receptor
- Smooth muscle contraction
- Glycogenolysis
- Sympathetic synaptic transduction
-
Alpha-2 receptor
- Regulation of transmitter release in the CNS
16
Q
Receptors
General effect of catecholamines on beta receptor
A
-
Beta-1 receptor
- Stimulation of the heart
- Stimulation of adipose cells
-
Beta-2 receptor
- Smooth muscle relaxation
- Increase of metabolism
17
Q
Receptors
Effects of catecholamines on circulation
A
- Similar to effects of sympathetic nervous system
- Sympathetic activation
- Low epinephrine
- Beta effect
- Cardiac output ↑
- High epinephrine
- Alpha effect
- Vasoconstriction
- Binding protein ↑
- High norepinephrine
- Similar to high epinephrine
- Effect depends on plasma concentration of hormone, receptor types and ratio of receptor types
19
Q
Receptors
Effects of catecholamines on particular organs
A
20
Q
Alarm reaction
A
- “Fight or flight” reflex
- Adrenal medulla has an important role in the formation of the “alarm-reaction” (Cannon’s reaction) during stress
- Enables rapid utilization of high amount of energy
