The Canadian Drugstore - Cialis Ne Icin Kullanilir

The Canadian Drugstore - Cialis Ne Icin Kullanilir

PROSTAGLANDINS,THROMBOXANES & LEUCOTRIENES
Diet
(Fish oils)
COO
COO-
Eicosapentaenoic
acid
-Linolenate
COO-
Arachidonate
6.2.1.15
CO.SCoA
Arachidonyl-CoA
CH2OR
CO. 'OCH
CH2OR
OH OH
O
HOCH
CH2O PO
Histamine
Adrenaline
Thrombin
etc.
HO
O-
Phosphatidyl inositol
O-
OH
OH
HO OH
OH
Lysophosphatidylinositol
1.13.11.12
Arachidonate
2O2
Non-steroidal
Anti-inflammatory
Prostaglandin
Drugs
synthase
eg. Aspirin
COO-
Leucotriene B4
COOOH O
5.3.99.3
O
OH
OH
COO-
COOOH
Prostaglandin PGH2
OH
5.3.99.4
OH
Prostacyclins
OH
O
OH
OH OH
Phospholipase A2
3.1.1.4
Steroidal
Anti-inflammatory
Drugs
O
O
CH2O PO
COO-
COOO
HO
OH
Prostaglandin PGE2
OH
Thromboxane B2
5.3.99.5
ENDOPLASMIC RETICULUM
Prostaglandins and the other related eicosanoids are localised, almost ubiquitous, and transient "hormones" involved in
a variety of physiological effects which can have very differing and even converse activities in differing tissues. These
include involvement in inflammatory reactions such as rheumatoid arthritis, in the control of blood pressure,
in blood clotting, in the induction of labour or in the aggravation of pain and fever.
Arachidonic acid arises from g-linolenic acid ñ an ìessentialî lipid which must be obtained from the diet. It is then metabolised
to become an acyl group in phospholipids (especially phosphatidylinositol) which are part of the membrane of the endoplasmic
reticulum, from whence it is released as the free arachidonic acid by phospholipase A2. This enzyme is activated by a variety
external stimuli such as adrenaline, histamine, or thrombin, and is inhibited by corticosteroids and other so-called
Steroidal Anti-inflammatory Drugs which thus prevent the re-formation of arachidonic acid - the precursor of prostaglandin.
The oxidative cyclisation of arachidonate into prostaglandins takes place in the lumen of the endoplasmic reticulum by the
prostaglandin synthase complex which has cyclooxygenase and peroxidase components, the former of which can be
inhibited by aspirin and other non-steroidal anti- inflammatory drugs
The reaction by which Prostaglandin is formed from arachidonic acid is one of the great "hidden treasures " of metabolism
which gives a very satisfying explanation of one of the most universal of drug therapies - why does aspirin relieve
headaches - and worse?
ENZYMES
1.13.11.12
3.1.1.4
5.3.99.3
Lipoxygenase
Phospholipase A2
Prostaglandin E synthase
5.3.99.4
5.3.99.5
6.2.1.15
Designed by Donald Nicholson
Prostacyclin synthase
Thromboxane A synthase
Arachidonate-CoA ligase
c 2002 IUBMB
of