About fatty acids

1. 08-03-2023
Eicosanoids
Classification
Eicosa
20
C
compounds
Eicosanoids
-
PG
and
related
c
ompouncts
Synthesized
from
arachidon
icacid
Prostaglandin
Prostaglandin
(PGs)
Prostacyclin
(PGIs)
Thromboxane
(TXs)
Metabolic
regulators
Local
hormones
(G
proti
couplec
receptors)
Leukotriene
&
Lipoxin
Structure-Prostaglandins
Prostaglandins
(PGs)
Isolated
from
prostatic
tissues
Present
in
almost
all
cells
except
RBC
(
lacl:
Cox)
cOOH
Cyclopentane
ring(C8-C12)
Substituent
groups
(
Keto
or
hydroxyl)
-
A
to
J
Naturally
occurring
PGs
alpha
oriented
OH
ggp
at
C-15
pros
ancc
acid
Structure
Series
1-Linolenic
acid
1
double
bond
-
13-14(frans)
Series
2-
Arachidonic
acid
2
double
bond-13-14
(fran)
5-6
(cis)
Series
3--
Eicosapentaengte
acid
3
double
bond
-
13
-
14(trans)
4
5-6
(cis)
&7-18(trans)
Subscript-
Number
of
double
bond
-
PGE,.
PGE2
PGI
has
additional
ring
Thromboxanes
are
similar
but
have
a
6-member
ing

2. -03-2023
Phospholipid
PL
Eplnephrine
or
Bradykinin+
Phospholipase
A
Cortisol
Phospholipase
A2
Arachidonic
acid
Arachidonic
acid
CYCLOOxYGENASE
(Cox)
Prostaglandin
G
Prostaglandin
H
Synthase
LIPOOXYGENASE
CYCLOOXYGENASE
2GSM
PEROXIDASE
G-S-S-G
Prostaglandin
&Thromboxane
Leukotriene
Prostaglandin
Ha
&
Lipoxin
Prostaglandin
H,
ENZYMES
Prostacyclin
synthase
Thromboxane
synthase
PGH
synthase
(
COX&
Peroxidase)
2
isoenzymes
PGHS-1
(cox
1)
-
Constitutive
enzymes
-
PG
synthesis
PGHS-2
(cox
2)-Inducible
-
responsible
for
inflammatory
response
PG
I2
TX
A2
lsomerase
isomerase
Reductase
PG
D,
PG
F2
COX-suicide
enzyme
Short
lived
and
rapidly
inactivated
PG
E2
Prevents
excessive
production
of
prostaglandins

3. 8-03-202
Inhibition
of
PG
synthesis
Degradation
of
Prostaglandins
Phospholipase
A2
Metabolised
rapidly
Corticosteroids
Lungs
&Liver
Enzymes
involved
are
15-hydroxyprostaglandin
dehydrogenase
13-prostaglandin
reductase
(less
significant)
COX-Anti-inflammatory
drugs
Aspirin
ireversibly
inhiblits
COX
Indomethacin
1.
Effect
on
CVS
-
regulation
of
blood
pressure
Prostacyclin/
PG
Synthesized
from
vascular
endothelium
Biological
Functions
&
Vasodilator
Clinical
Applications
of
Prostaglandins
Inhibits
platelet
aggregation
&
prevents
thrombu:
formation
Thromboxane
/
TXA2
Synthesized
by
platelets
Vasoconstrictor
Increases
platelet
aggregation

4. 8-03-202
Clinical
Application
2.
Effect
on
respiratory
system
PGE-Bronchodilator
PGF2-Bronchoconstrictor
Used
in
the
treatment
of
hypertension
Clinical
Application
Prostacyclin
&Thromboxane
are
anliaonistic
in
their
action.
PGE
Used
in
the
treatment
of
astima
In
co-ordination
they
function
to
balae
the
blood
homeostasis
3.
Effect
on
uterine
muscles
&
ovaries
4.
Effect
on
GIT
PGF2
Stimulates
uterine
muscle
contrachio
PGE2
Supress
gastric
secretion
Increases
intestinal
motility
Causes
LH
induced
ovulation
Clinical
Application
Induction
of
labour
Clinical
Application
Medical
gemination
of
pregnanc
y[hTP)
Aresting
of
post
partum
hemorhege
Used
in
the
treatment
of
peptic
ulcer

5. 8-03-202
5.
Effect
on
inflammation
&
immunity
Other
effects
PGE2
Decreases
lipolysis
Increases
glycogenesis
Increases
calcium
mobiliiabn
from
one
Increases
GFR
and
promes
i
urine
oi
tput
Increases
sodium
&
potasm
excretion
Increases
capillary
permeability
Induces
swelling,
redness
and
oedema
Reduces
both
T
cell
and
Bcell
functions
6.
Effect
on
pain
and
fever
Pyrogens
promote
PGs
synthesis
PGE2
causes
pain
PGE2
causes
migraine
Therapeutic
applications
of
Prostaglandins
Leukotrienes
Produced
in
leucocytes,
platele,
macrophag
s..
Oxidation
of
arachidonic
acid
bs-Lipooxyge
nase
LT-grouped
into
five
classes
(Ae)
LTA,
LTB,
LTC,
LTD
LTE
Asthma
Hypertenslon
Peptic
ulcer
Induction
of
labour
Medical
germination
of
pregnancy(MTP)
Aresting
of
post
partum
hemorhage
Patent
Ductus
arterlosus
PGE2

6. 8-03-202
Functions
Actlvate
the
immune
response
LTB4-most
potent
cheriagectic
age
nt
Modiators
of
hypersensiti
vg
reaction
Induce
contraction
of
smoD
th
musce,
bronchoconstriction,
vasodi{btation-seen
during
anaphylactic
shock
Mixluro
of
LT
C4,
D4
and
E4-Lentified
a:
slow
reacking
substance
of
anapylAxis
(SRS-A)
Thist
mixture
is
100-1000
timesmpre
potent
than
histamine
and
prostaglanding
(as
a
const
ictor
of
Bronoial
Smooth
Muscle)
Over
production
of
LT
case
asthm«itic
attacks
Lipoxins
Produced
by
leucocytes
Conjugated
tetraenes
LXA4,
LXB4,
LXC4,
LXD4,
LxE4
Anti-inflammatory
actior