Histamine Receptor and Effects

Question 1

Secondary Cell Messenger

Answer 1

cAMP (c = cyclic)

Question 2

Substance that trigger allergies

Answer 2

Allergen

Question 3

Low blood pressure

Answer 3

Hypotension

Question 4

Swelling caused by too much water trapped in body’s tissue

Answer 4

Edema

Question 5

Fatty acids that contain more than one double bond in their backbone

Answer 5

Polyunsaturated Fatty Acids (PUFA)

Question 6

A biological catalyst that speeds up the rate of a specific chemical reaction in the cell

Answer 6

Enzyme

Question 7

BBB

Answer 7

Blood-Brain Barrier

Question 8

SSRI

Answer 8

Selective Serotonin Reuptake Inhibitors

Question 9

A compound which is released by cells in response to injury and in allergic and inflammatory reactions, causing contraction of smooth muscle and dilation of capillaries

Answer 9

Histamine

Question 10

Synthesized by amino acid called ___ , and stored with in the ___ found on tissues, ___ in blood vessels, and ___ in the stomach lining

Answer 10

histidine; granules of mast cells; basophil and eosinophil; enterochromaffin-like

Question 11

Distribution and Storage Sites of Histamines (3)

Answer 11

1. The Primary Tissue Sites (lungs, skin, mucosal layer of the stomach, basophil)
2. Mast Cells
3. Central Nervous System
4. Others

Question 12

Factors Mediating the Release of Histamines (5)

Answer 12

1. Allergic reactions
2. Physical injury
3. Immune release
4. Drugs and Foreign Chemical
5. Plant and Animal Sting

Question 13

Present on the vascular endothelial cell, smooth muscles, brain and peripheral nerve ending

Answer 13

H1 Receptors

Question 14

[H1 receptors]

Contraction of smooth muscle and neuronal actions are due to increases in ___ and activation of ___ .

Answer 14

Calcium Ion; protein kinase C

Question 15

[H1 Receptors]

Relaxation of vascular smooth muscle involves ___ .

Answer 15

Ca2+ -induced formation of nitric oxide (NO)

Question 16

H1-receptors mediate ___ . (3)

Answer 16

1. contraction of bronchiolar and intestinal smooth muscle,
2. vasodilation of small arteries and veins,
3. increased capillary permeability and pruritus

Question 17

Stimulation of Gs-coupled H2 receptors activate adenylyl cyclase and increase tissue cAMP levels. This is the mechanism by which vascular smooth muscle relaxes, and gastric acid secretion is stimulated.

Answer 17

H2 Receptors

Question 18

This is the mechanism by which vascular smooth muscle relaxes, and gastric acid secretion is stimulated.

Answer 18

Stimulation of Gs-coupled H2 receptors activate adenylyl cyclase and increase tissue cAMP levels.

Question 19

Inhibition of the release of histamine and other neurotransmitters involves inhibition of cAMP synthesis, opening of K+ channels to increase K + efflux, and closure of Ca2+ channels to block Ca2+ entry into the nerve.

Answer 19

H3 receptors

Question 20

These receptors are selectively expressed in mast cells, basophils, and eosinophils. Activation of ___ receptors mediates histamine-induced mast cell chemotaxis and leukotriene B4 production.

Answer 20

H4 Receptors

Question 21

Physiologic and Pathologic Roles of HIstamine Receptors

Answer 21

1. Gastric Acid Secretion
2. Allergic Reaction and Anaphylactic Shock
3. Inflammation
4. Neurotransmission
5. Microcirculation

Question 22

Body systems that has pharmacologic effects of Histamines

Answer 22

1. Cardiovascular system
2. Respiratory system
3. Glandular system

Question 22

• Histamine dilates arterioles, capillaries, and venules, increases cardiac contractility and heart rate by activating both H1– and H2-receptors.
• There is an increase in capillary permeability brought about by contracting the endothelial cells, which exposes the basement membrane.

Answer 22

Cardiovascular system

Question 23

*** smooth muscles is contracted in most species via H1-receptor

Answer 23

Respiratory system