Amino acid based mediators- Histamine and 5HT

Question 1

histamine is a ____ amine derived frm _____

Answer 1

basic

histidine

Question 2

tissue histamine is proportional to

Answer 2

tissue mast cell content

Question 3

there is a high conc of mast cells in

Answer 3

skin and mucous membranes

Question 4

nonmast cel histamine comes frm

Answer 4

brain (NT) and stomach (signals acid secretion)

Question 5

Mast cell histamine release id mediated by

Answer 5

IgE
complement stimulated
initiated by rise in intracellular calcium levels

Question 6

how many types of histamine receptors are there

Answer 6

4

Question 7

histamine receptors are coupled to

Answer 7

GPCR

Question 8

which H receptor is for allergy and inflammation

Answer 8

H1

Question 9

which H receptor stimulates gastric acid secretion

Answer 9

H2

Question 10

wheal and flare entails

Answer 10

local vasodulation, vascular permeability, stimulation of nerve endings in skin

Question 11

antihistamines exert effects primarily by acting on

Answer 11

H1 receptor

Question 12

peptic ulcer drugs act on

Answer 12

H2 as antagonists

Question 13

antihistamines are ____ agonists

Answer 13

inverse

Question 14

5HT is synthesized from

Answer 14

tryotophan

Question 15

5HT is degraded by

Answer 15

MAO

Question 16

functions of 5HT in vascular system and in CNS

Answer 16

local hormone in vascular system

neurotransmitter in CNS

Question 17

where is 5HT found

Answer 17

enterochromaffin cells of intestinal wall
blood platelets
CNS

Question 18

_____ and _____ have high affinity reuptake transporters such as ____

Answer 18

platelets and neurons

SERT

Question 19

effects of 5HT(6)

Answer 19

• vascular constriction in larger vessels and dilation of arterioles
• smooth muscle contraction in bronchi and uterous
• increases GI motility
• stimulate platelet aggregation
• stimulate peripheral nociceptive nerve endings
• excitation/ inhibition in CNS

Question 20

pathophysiological effects of 5HT

Answer 20

migraine 
pulmonary hypertension
carcinoid syndrome
nausea, vomiting
mood disorders and anxiety

Question 21

4 migraine phases

Answer 21

1. premonitory phase
2. aura
3. headache
4. postdromal phase

Question 22

migraine theories

Answer 22

1. vascular
2. brain
3. neuroinflammation

Question 23

vascular migraine theory

Answer 23

intracerebral vasoconstriction, followed by vasodilation

Question 24

brain migraine theory

Answer 24

wave of cortical spreading depression

Question 25

neuroinflammation migraine theory

Answer 25

activation of trigeminal nerve terminals in meninges and extracranial vessels

Question 26

what happens to 5HT concentrations in the blood during a migrane attack

Answer 26

falls | - increase in 5-HIAA metabolite in urine

Question 27

sumatriptan mechanism

Answer 27

5HT receptor agonist = causes vasoconstriction and inhibits trigeminal nerve transmission

Question 28

side effects of sumatriptan

Answer 28

coronary vasoconstriction | dysrhythmia

Question 29

what are some prophylactic antimigraine drugs

Answer 29

pizotifen and cyproheptidine

Question 30

pizotifen and cyproheptidine are

Answer 30

5HT receptor antagonists that prevent vasoconstriction

Question 31

side effects of pizotifen and cyproheptidine

Answer 31

weight gain, sedation, antimuscarinic effects

Question 32

carcinoid syndrome

Answer 32

rare tumor or cancer of enterochromaffin cells = excess amounts of 5HT

Question 33

what is used as treatment of carcinoid syndrome, mechanism

Answer 33

cyproheptadine | - 5HT2 receptor antagonist

Question 34

symptoms of carcinoid syndrome

Answer 34

``` flushing diarrhea bronchoconstriction hypotension fibrotic stenosis of heart valves ```

Question 35

5HT1 is responsible for

Answer 35

cerebral vasoconstriction

Question 36

5HT2 is responsible for

Answer 36

smooth muscle contraction platelet aggregation vasoconstriction