Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacology > AUTOCOIDS & AUTOCOID ANTAGONISTS > Flashcards

AUTOCOIDS & AUTOCOID ANTAGONISTS Flashcards

1
Q

Non neuronal site of histamine storage

A

Enterochromaffin-like cells of the fundus of the stomach —> release histamine, which activates acid-producing parietal cells of the mucosa.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mast cells

A

Rich at sites of potential tissue injury: nose, mouth, feet, internal body surfaces, and blood vessels (esp @ pressure points and bifurcations)

Granules store histamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

H1 receptors

A

In brain, located on postsynaptic membranes.
Also present in endothelium, smooth muscle cells and nerve endings.

Coupled to PLC —>
activation causes IP3 and DAG formation —> IP3 = release of Ca2+ from ER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

H2 receptors

A

In brain, located on postsynaptic membranes.
Also located in gastric mucosa, cardiac muscle cells and some immune cells.

Linked to stimulation of adenylyl cyclase —>
Activation of cAMP-dependent protein kinase in target cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

H3 receptors

A

Predominantly presynaptic receptors

Reduce transmitter release from histaminergic and other neurons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

H4 receptors

A

Mainly found on leukocytes in the bone marrow and circulating blood

Chemotactic effect on eosinophils and mast cells —> important role in inflammation and allergy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

CVS Effects of Histamine

A

-Vasodilation (H1 & H2)
H1: higher histamine affinity, rapid and short response (located on endothelial cells; formation of NO)
H2: dilation develops slowly and is more sustained (located on vascular smooth muscle, vasodilation mediated by cAMP)
Dec BP usually leads to reflex tachycardia

-Inc contractility and rate (H2)
In atrial muscle, can also lead to dec contractility (H1)

-Inc capillary permeability (H1 on vessels of micro circulation, esp post capillary vessels)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The Triple Response

A

1) A localized red spot (direct histamine vasodilatory effects)
2) A brighter red flush or flare ( indirect vasodilatory effect d/t histamine induced stimulation of axon reflexes
3) A wheal seen in 1-2 minutes (histamine’s capacity to cause edema)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Extravascular smooth muscle

A

GI tract - contraction of intestinal smooth muscle (H1)

Bronchiolar - bronchoconstriction (H1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Nervous System effect of Histamine

A

Powerful stimulant of sensory nerve endings, esp those mediating pain and itching ( H1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Physiological histamine antagonist

A

Epinephrine

Act on different receptors than histamine

Injection can be life-saving in systemic anaphylaxis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Histamine release inhibitors

A

Cromolyn and Nedocromil

Reduce degranulation of mast cells that result from immunologic triggering by antigen-IgE interaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Histamine effect on secretory tissue

A

Gastric acid secretion and, to a lesser extent, gastric pepsin and IF production (H2 mediated)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

H2 receptor antagonists

A
  • cimeTIDINE, raniTIDINE, famoTIDINE, nizaTIDINE
  • inhibit gastric acid secretion (block H2 receptors = dec cAMP)
  • uses: peptic ulcers, acute stress ulcers, GERD

-Adverse effects: less than 3% of cases; extremely safe drugs
Cimetidine inhibits CYP450; also binds to androgen receptors (antiandrogenic effects = gynecomastia and reduced sperm count in men, galactorrhea in women)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Serotonin

A
  • rapidly oxidized by MAO
  • over 90% found in enterochromafgin cells in GI tract
  • in blood, found in platelets
  • is a precursor of melatonin in the pineal gland
  • Raphe nuclei of the brain stem: contain cell bodies of serotenergic neurons that synthesize, store and release serotonin as a NT.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

GI tract effect of serotonin

A

Increases GI motility (5HT2 smooth muscle receptors)

Overproduction of serotonin in carcinoid tumor results in severe diarrhea

17
Q

CVS effect of serotonin

A

-constricts large vessels (both arteries and veins) (5HT2 receptor activation on vascular smooth muscle cells)

18
Q

Serotonin effect on platelets

A

Platelet aggregation (via 5HT2a receptors)

19
Q

Nervous system effect of serotonin

A
  • excited some and inhibits other neurons
  • 5HT3 receptors in GI tract and vomiting center in medulla participate in vomiting reflex
  • 5HT3 receptor effect involved in pain and itch sensation
20
Q

Sumatriptan

A

5HT1D/1B receptor agonist (triptans)

Used almost exclusively in migraines

MOA: activation of postsynaptic 5HT1b = vasoconstriction. Activation of presynaptic 5HT1D = inhibit release of CGRP (a powerful vasodilator). Inhibition of pain transmission by inhibiting trigeminal neurons

Adverse: triptans may cause coronary vasospasm, this are contraindicated in pts with CAD or angina

21
Q

Metoclopramide

A

5HT4 receptor agonist

Prokinetic (enhances GI motility)
—>Facilitates ACh release from enteric neurons

22
Q

Cisapride

A

5HT4 agonist

Prokinetic agent

*No longer generally available in the US d/t adverse cardiac effects (extends AP, prolong mA QT interval, serious cardiac arrhythmia sand deaths from VT, VF, torsades de pointes)

23
Q

Cyproheptadine

A

5HT2 receptor antagonist

Prevents smooth muscle effects of both serotonin and histamine (but has no effect on gastric secretion by histamine)

Uses: allergic rhinitis, vasomotor rhinitis, allergic conjunctivitis. Treatment of serotonin syndrome (caused by overstimulation if 5HT1a and 2 receptors - may be fatal, causes hyperthermia, muscle rigidity and myoclonus)

24
Q

Ondanestrone

A

5HT3 receptor antagonist

Anti-emetic drug, particularly for controlling severe N/V in pts on chemo

25
Q

Ergot alkaloids

A
  • ergotamine, dihydroergotamine, bromocriprome, cabergoline, ergonovine, methylergonovine
  • MOA: act on several types of receptors. Effects include agonist, partial agonist, and antagonist action @ alpha-adrenoreceotors and 5HT receptors; and agonist or partial agonist @ CNS dopamine receptors

Uses:

  • migraine
  • hyperprolactinemia
  • postpartum hemorrhage
  • dx of variant angina

Adverse:
-N/V

26
Q

Eicosanoids

A

Principal subgroups: prostaglandins, prostacyclin, thromboxanes and leukotrienes

Not preformed in tissue, are generated de novo from phospholipids (mainly arachidonic acid, which is found esterified in phospholipids, usually in the 2nd position)

2 major pathways of eicosanoid synthesis:

  1. Cyclo-oxygenate: prostaglandins, prostacyclins and thromoxanes
  2. Lipoxygenase: leukotrienes, and other compounds
27
Q

MAO of Eicosanoids

A
  • act in autocrine and paracrine fashion
  • bind to receptors on cell surface, all which are G protein coupled
  • some coupled to activation of PLC, some to activation of adenylyl cyclase, some to inhibition of adenylyl cyclase
  • contractile effects on smooth muscle mediated by release of Ca2+, relaxation medicated by elevations in cAMP
28
Q

Dinoprostone

A

PGE2

Used to ripen the cervix @ or near term

Can be used as an abortifacient

29
Q

Misoprostol

A

Synthetic derivative of PGE1

Used to ripen the cervix @ or near term

Can be used for the management of postpartum hemorrhage

Approved for the prevention of peptic ulcers in pts who must take high doses of NSAIDS

30
Q

Alprostadil

A

PGE1

Given IV to maintain latency of ductus arteriosus in infants with transposition of the great vessels until surgical correction can be undertaken

Used in the treatment of impotence

Preparations available for injection into the penis as well as for insertion into the urethra.

31
Q

Prostacyclin

A

PGI2

Lowers peripheral, pulmonary and coronary resistance

32
Q

Epoprostenol

A

Commercial preparation of PGI2

Severe HTN & to prevent platelet aggregation in dialysis machines

33
Q

Latanoprost

A

A PGF2alpha derivative used for the treatment of glaucoma

Increases the outflow of aqueous humor, thus reducing intraocular pressure

34
Q

Zileuton

A

5-lipooxygenase inhibitor

Prevents leukotriene synthesis

35
Q

Zafirlukast, Montelulast

A

LTD4 receptor antagonists

Prevent LTD4 from binding to its receptor in target tissues, thereby preventing its action

36
Q

Glucocorticoids

A

Inhibit cytosolic phospholipids A2, this blocking the release of arachidonic acid from phospholipids, and its subsequent conversion to eicosanoids.

Also inhibit COX-2 synthesis

37
Q

NSAIDS

A

Act primarily by inhibiting COX enzymes

Group of agents with antipyretic, analgesic, and anti-inflammatory activities.

38
Q

Cimetidine

A

H2 receptor antagonist

Inhibits cytochrome P450 and can slow metabolism of several drugs

Antiandrogenic efffects

Pharmacology (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions