BIOCHEMISTRY-FLASHCARDS-THIRDLONGS-EICOSANOIDS

Question 1

Origin/Precursor of arachidonic acid

Answer 1

Linoleic acid

Question 2

Three classes of Eicosanoids

Answer 2

Prostaglandins, Thromboxanes and Leukotrienes

Question 3

Two pathways of in the synthesis of Eicosenoids

Answer 3

Cyclic Pathway and Linear Pathway

Question 4

PGH2 is the precursor of what—-

Answer 4

PGI2, TXA2, PGE2, PGF2a

Question 5

Enzyme in the reaction to produce PGI2

Answer 5

prostacyclin synthase

Question 6

Enzyme In the reaction to produce TXA2

Answer 6

Thromboxane synthase

Question 7

Enzyme in the reaction to produce PGE2

Answer 7

isomerase

Question 8

Enzyme in the reaction to produce PF2a

Answer 8

reductase

Question 9

Produced by blood vessel endothelium. Inhibits plately aggregation and causes vasdilation and lowers systemic arterial pressure

Answer 9

PGI 2

Question 10

produced by most tissues, especially kidneys, dilates renal blood vessels and increases renal blood flow. Regulates Na+ excretion and GFR. Promotes uterine contraction, platelet aggregation, vasodilation, relaxation of smooth muscles in the intestines

Answer 10

PGE2

Question 11

produced by most tissues, promotes contraction of smooth muscles, vasoconstriction, and contraction of uterine muscles

Answer 11

PGF2

Question 12

produced primarily by the platelets and causes platelet aggregation, vasoconstriction, mobilizes intracellular Ca2+ and contraction of smooth muscle

Answer 12

TXA2

Question 13

What can 5HPETE be converted to?

Answer 13

5HETE and Leukotrine A4

Question 14

LTA4’s fates

Answer 14

Leukotriene B4 (LTB 4) or Leukotriene C4 (LTC4)

Question 15

FUNCTIONS of LTB4

Answer 15

Chemotatic agent, induces PMN Leukocytes and releases lysosomal hydrolytic enzymes, stimulates adenylate cyclase, immunosuppressive activity, adhesion WBC and release of lysosomal enzymes

Question 16

Functions of LTC4 -> LTD4 -> LTE4

Answer 16

Hormonal Agents, Comprise the slow reacting substance of anaphylaxis

Question 17

2 well studied isoforms of COX-1

Answer 17

COX-1 and COX-2

Question 18

isoform of COX that is responsible for the synthesis of prostaglandins required for maintenance of healthy GIT epithelium, renal homeostasis and thromboxane formation in platelts

Answer 18

COX-1

Question 19

Inhibits COX-1

Answer 19

NSAIDS

Question 20

Isoform of COX that is responsible for the synthesis of prostaglandins required for pain and inflammation. Is needed in angiogenesis (blood vessel development) which is essential to tumor growth

Answer 20

COX-2