Mediators of Inflammation: Leukotrienes and Hisatmine Flashcards
Vocab
AA
arachidonic acid
COX
cyclooxygenase enzyme
GSH
reduced glutathionie
H1 and H2
histamine receptors 1 and 2
LT
Leukotrienes LTA(4), LTB()4), LTC (4)m LTD(4)
5-LO
5-Lipoxygenase
NSAID
non-steroidal anti-inflammatory drug
PG
prostaglandin
PGI
prostacyclin (Prostaglandin I(2))
PUFA
polyunsaturated fatty acid
TNF-alpha
tumor necrosis factor
TxA(s)
thromboxane A(2)
Cells rich in COX =
smooth muscle, fibroblasts, epithelia, endothelia, hematopoietic cells
less in neutrophils
Cells rich in 5-LO
myeloid cells
AA –> LTXs: enzymes
Phospholipase A(2) + phospholipid –> AA or PUFA
w5-LO + O2+ FLAP + w5-LO accessory protein+ AA or PUFA –> LTA(4)
xLTA(4) Hydrolase + LTA(4)+ H20 –> LTB(4)
yLTC(4) synthase + GSH –> LTC(4)
z Peptidases + LTC(4) –> LTD (4), LTE (4)
phospholipase A(2)
converts phospholipids into AA or PUFA
5-LO, Ca2+, FLAP
5-lipoxygenase enzyme, (5-LO activating protein)+ accessory 5-LO protein, and Calcium
converts PUFA or AA with O2 into LTA(4) in
LTA (4) hydrolase
converts LTA(4) into LTB(4) along with hydrolysis
LTC(4) synthase
converts LTA(4) and GSG into LTC(4)
Peptidases
convert LTC(4) into LTD(4) and LTE (4)
What makes a leukotriene a leukotriene?
a) they’re made by leukocytes and b) they have a conjugated system consisting of three double bonds
Prostaglandins, thromboxane, leukotrienes and other eicosinoids are considered
autacoids, not hormones
characteristics of these eicosinoids
made upon demand
biosynthesis of latent
short lived
local, not systemic actions
