Lec 1 - Histamine

Question 1

inflammatory histamine is synthesized in mast cells and ____

Answer 1

basophils

Question 2

histamine is complexed in storage granules with sulfated polysaccharides, such as _____, chondroitin sulfate, and _____

Answer 2

heparin sulfate, proteases

Question 3

non-mast cell histamine is found in some areas of the _____; it is also seen in the __ of the stomach

Answer 3

brain;

fundus

Question 4

histamine is released when antigens bind Ig___ on mast cells. the Ig molecule is bound to ____ receptors.

Answer 4

E;

FcER1

Question 5

histamine is also released with ___ or mechanical stress, cytotoxic agents such as ____. and various drugs such as high dose _____

Answer 5

thermal, venoms;

morphine

Question 6

clustering of FcER1 receptors causes an influx of ____ into the cell, triggering release of histamine. what drug prevents histamine release?

Answer 6

Calcium;

cromylyn sodium

Question 7

The H1 receptor is G ___ Coupled. binding causes an increase in what 2 signalling molecules?

Answer 7

q;

IP3 and DAG

Question 8

H1: an increase in IP3/DAG causes an increase in _____. this increase causes smooth muscle _____.

Answer 8

calcium;

contraction

Question 9

binding of H1 receptors also causes an increase in ____. This causes vasodilation due to effect on ____ Cells

Answer 9

NO;
endothelial

histamine constricts veins *

Question 10

H1 receptors are mainly found in what 2 organ systems?

Answer 10

cardiovascular;

respiratory

Question 11

____ receptors are responsible for stimulation of sensory nerves, causing sneezing and ____

Answer 11

H1; itching

Question 12

binding of _____ causes endothelial cells to contract, causing a ____ in vascular permeability and ___

Answer 12

H1;
increase;
edema

Question 13

binding of ____ in the lungs causes bronchoconstriction

Answer 13

H1 receptors

Question 14

____ receptors are linked to relaxation of vascular smooth muscle and gastric secretion

Answer 14

H2

Question 15

H2 receptors are G ___ coupled. binding causes an increase in what signalling molecule?

Answer 15

s, cAMP

Question 16

H3 receptors are located mainly in the ____. They are linked to inhibition of _____ release via a decrease in ____ influx

Answer 16

CNS;

NT, Ca

Question 17

H4 receptors are located on ______. they are linked to histamine-induced _____

Answer 17

mast cells, basophils, eiosinophils;

chemotaxis

Question 18

H2 receptors moderate an increase in ____ and _____ in the heart. This is due to increase in cAMP whic binds ____ and thus causes an increase in ____ entry

Answer 18

rate, force of contraction;

PKA; Calcium

Question 19

which H receptor is responsible for acid release in the stomach

Answer 19

H2

Question 20

on the skin, histamine causes ___ and ____ in response to insect bites

Answer 20

flare, edema

Question 21

H1 antagonists are predominantly ____ _____

Answer 21

inverse agonists

Question 22

3 H1 antagonists ending in “mine”;

2 ending in “zine”

Answer 22

bromphenira-. diphenhydra-, pyrila-;
hydroxy-, prometha- (also meclizine)

cyproheptadine also mentioned in notes

Question 23

1st generation antagonists (especially ____ and _____) have what side effect?

Answer 23

diphenhydramine, promethazine;

sedation

Question 24

_____ has potent anti-motion sickness and anti-emetic effects

Answer 24

promethazine

Question 25

first gen H1 blockers are more ____ soluble than 2nd gen. they thus cross the BBB _____ easily

Answer 25

lipid;

more

Question 26

H1 antagonists have anti ____, _____, and ____ effects as well

Answer 26

muscarinic, cholinergic, sertonergic

Question 27

phenothiazine and promethazine can also cause ____ side effects

Answer 27

extrapyramidal (dystonia, akathisia)

Question 28

2nd gen H1 antagonists include these 4:

Answer 28

loratadine, desloratadine, fexofenadine, cetirizine

Question 29

in addition to decreased lipid solubility, why don’t 2nd gen H1 blockers enter the CNS?

Answer 29

efflux via P-glycoprotein transporter

Question 30

_____ is a physiologic antagonists to histamine

Answer 30

epinephrine