Noradrenaline Synthesis, Release And Storage

Question 1

Where are cholesterol processing enzymes located in the cell

Answer 1

Smooth ER and inner mitochondrial membrane
Parenchyma cells can produce cholesterol de novo by Endocytosis of LDL, cholesterol rich lipid droplets in cytoplasm

Question 2

Cells in the adrenal medulla are called

Answer 2

Pheochromocytes

Question 3

In adrenal medulla how many % of E and NE are released

Answer 3

E- 80%
NE- 20%

Question 4

How are epinephrine and norepinephrine released

Answer 4

Secreted into the blood by exocytosis of chromaffin granules

Question 5

Volume of L-tyrosine in plasma

Answer 5

1-1.5mg/dl

Question 6

Plasma ration of epinephrine and norepinephrine

Answer 6

NE-80%
E-20%
8:2

Question 7

List the excitatory and inhibitory adrenergic receptors

Answer 7

Alpha1 and beta 1- excitatory
Alpha2 and beta2- inhibitory

Question 8

Location of alpha 1 adrenergic receptors and examples of response elicited

Answer 8

Most sympathetic target cells
NE>E
Generalized arteriolar vasoconstriction

Question 9

Location of alpha 2 adrenergic receptors and examples of response elicited

Answer 9

Digestive system
NE>E
Decreased motility in the digestive tract

Question 10

Location of beta 1 adrenergic receptors and examples of response elicited

Answer 10

Heart
NE=E
Increased rate and strength of cardiac muscle contraction

Question 11

Location of beta 2 adrenergic receptors and examples of response elicited

Answer 11

Skeletal muscle,smooth muscle of some blood vessels and organs
Breakdown of glycogen in skeletal muscle
Bronchiolar dilation and arteriolar vasodilation in skeletal muscles and heart

Question 12

Cofactors of tyrosine hydroxylase

Answer 12

Fe2+
Tetrahydrobiopterin

Question 13

Cofactors of L-aromatic amino acid decarboxylase

Answer 13

Pyridoxal phosphate

Question 14

Where is dopa decarboxylase stored

Answer 14

Stored in secretory vesicles
Enter by active transport
VMAT- vesicular mono amine transporters

Question 15

Cofactor of dopamine beta hydroxylase

Answer 15

Copper and vitamin C

Question 16

Cofactor of PNMT

Answer 16

SAM- S-adenosylmethionine

Question 17

Expression of PNMT depends on

Answer 17

Expression depends on high local cortisol from adrenal

Question 18

Where are catecolamines stored

Answer 18

In secretory vesicles and they enter via VMAT transporter

Question 19

PNMT is also found where in the body

Answer 19

Kidney, lungs, pancreas

Question 20

Other things in secretory vesicles asides E and NE are chromogranins, dopamine Beta hydroxylase, ATP, other peptides

Question 21

Catecholamines can reach most tissues except

Answer 21

Blood brain barrier
Fetus

Question 22

T or F catecholamines are short lived molecules

Answer 22

T 10sec to 1.7 min

Question 23

Catecholamines are how many percent associated with albumin

Answer 23

50-60% associated with albumin

Question 24

Elimination of Catecholamines

Answer 24

Reuptake into nerve terminals
Reenter through VMAT
Cleaved by MAO mono amine oxidase in the nerve terminal
In target cells degraded by COMPT (catechol-o-methyl transferase)
5% directly filtered to urine

Question 25

Where is Mao specifically found

Answer 25

Outer mitochondrial membrane of nerve

Question 26

Mao also breaks down

Answer 26

Serotonin and histamine

Question 27

Mao oxidized amino group to

Answer 27

Aldehyde

Question 28

End product of MAO is

Answer 28

DOMA dihydroxymandelicacid

Question 29

Two types of Mao

Answer 29

MAO-A for breakdown of E and NE
MAO-B: for breakdown of D,S,H

Question 30

End product of COMT in breakdown of E and NE is

Answer 30

Metanephrine and normetanephrine

Question 31

Normetanephrine can be further broken down into __________ by _______

Answer 31

VMA vanillymandelicacid
By mao

Question 32

Normetanephrine and metanephrine can still be acted upon by the liver

Answer 32

Sulfated or glucoronidated

Question 33

Inhibitors of tyrosine hydroxylase is

Answer 33

AMPT - alpha methyl para tyrosine

Question 34

Inhibitor of dopamine beta hydroxylase is

Answer 34

Disulphiram