Study Set Content:
POTENT INHIBITOR of platelet aggregation
PGI2
concentration of PGE 2 – enhance (via EP 3)
Low
concentration of PGE 2 – inhibit (via IP), platelet
aggregation
High
is the major product of COX-1, the only COX
isoform expressed in mature platelets.
TXA 2
Itself a platelet aggregator, TXA 2 amplifies the
effects of other, more potent, platelet agonist
such as
thrombin
Both the medulla and the cortex of the kidney synthesize
prostaglandins, the (blank) substantially more that the
medulla
is expressed mainly in cortical and medullary
collecting ducts and mesangial cells, arteriolar
endothelium, and epithelial cells of Bowman’s capsule.
COX-1
is restricted to the renal medullary interstitials
cells, the macula densa, and the cortical thick ascending
limb.
COX-2
The major renal eicosanoid products are
PGE2 and PGI2,
followed by
PGF 2a and TXA2
also synthesizes several
hydroxyeicosatetraenoic acids, leukotrienes, cytochrome
P450 products, and epoxides
kidney
Prostaglandins also plays important role in:
maintaining blood pressure and
o regulating renal function
Renal cortical COX-2-derived PGE 2 and PGI 2▪ maintain
renal blood flow and glomerular filtration rate through
their local
vasodilating effects
These prostaglandins modulate systemic blood pressure
through regulation of
water and sodium excretion
prostanoids increase medullary blood
flow inhibit tubular sodium reabsorption
COX-2-derived
products promote salt excretion in the
collecting ducts.
COX-1-derived
PGI2 stimulate (blank) release
renin
Inhibition of COX-2 may reduce (blank) in these
settings.
blood pressure
causes intrarenal vasoconstriction (and perhaps an
ADH like effect), resulting in a decline in renal function.
TXA2
is associated with increased TXA 2 and
decreased PGE 2 and PGI 2 synthesis in some animal
models, eg, the Goldblatt kidney model.
Hypertension
