3070: Prostaglandins

Arachidonic acid (AA) is the precursor to:

prostaglandins, thromboxanes, and leukotrienes

Where is arachidonic acid stored?

in the cell’s lipid membrane as a phospholipid

How is arachidonic acid released?

released upon activation of phospholipase A2 after tissue damage, toxin exposure, or hormonal stimulation

What suppresses Phospholipase A2?

Glucocorticosteroids (like hydrocortisone). are considered anti-inflammatory

What metabolizes arachidonic acid?

cyclooxygenase (COX) and/or lipoxygenase (LOX)

What converts arachidonic acid into prostaglandin G2?

COX 1 or COX 2

What converts Prostaglandin G2 into Prostaglandin H2:

Peroxidase

PGH2 can be converted into which PG’s?

PGE2, PGD2, PGF2, PGI2, and TXA2

Platelets have a high concentration of:

TXA synthetase

TXA2 released from platelets causes:

aggregation and vasoconstriction in response to vascular injury

COX 1 is always present in:

all tissues that produce PG and TX

COX1 is involved in:

gastric protection, platelet aggregation, inhibition of platelet aggregation (COX2 mediated), vasoconstriction, vasodilation

Which COX is inducible & present in inflammation:

COX2

COX2 are produced in inflammatory & immune cells in response to:

growth factors, tumor promoters, cytokines, endotoxins

What can inhibit COX2 expression?

Corticosteroids

Alprostadil use:

natural PG. used for ED and treatment of ductus arterious dependent congenital heart defects

Dinoprostone use:

natural PG. used for cervical ripening & labor induction, 2nd trimester abortion, and evacuation of uterine contents in fecal death

Epoprostenol use:

natural PG. used for primary pulmonary hypertension & scleroderma.

directly opposes TXA2

What are the 3 natural PG’s?

aprostadil, dinoprostone, & epoprostenol

Carboprost use:

modified PG. treats postpartum bleeding and for 2nd trimester abortions

given IM injection

Carboprost ADR:

NVD, bronchoconstriction, & increased body temp

Misoprostol use:

modified PG. prevents NSAID induced gastric ulcers in high risk patients

Misoprostol ADR:

has potential to induce abortions, abdominal pain, NVD, increased body temp

What are the 2 modified PG’s?

carboprost & misoprostol

Treprostinil use:

PG analog. pulmonary arterial hypertension.

Treprostinil ADR:

injection site/pain & hypotension

Iloprost use:

PG analog. pulmonary arterial hypertension

Iloprost ADR:

hypotension

What are the modified opthalmic PG’s?

travoprost, bimatoprost, latanoprost, unoprostone, & talfluprost

What is the use for the modified opthalmic PG’s?

reduce intra-ocular pressure in patients with open-angle glaucoma

What is the ADR for the modified opthalmic PG’s?

changes to eye color & eye lashes