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Name Of Eicosanoids
? Eicosanoids is a Generic term for the 20
Carbon related compounds like:
I. Prostaglandins (PGs)
I . Prostacyclins (PGI2)
I I. Thromboxanes (TX)
IV. Leukotrienes (LT)
V. Lipoxins (LX)
VI. Resolvins
VII. Eoxins
Biosynthesis Of Eicosanoids
? Eicosanoids are derivatives
of Nutritional Essential
Fatty acid/PUFAs.
? Eicosanoids are biosynthesized in the body
from PUFAs:
1.
Mostly from Arachidonic
acid/Eicosatetraenoic acid
(PUFA)/Omega 6 Fatty acid
2.
Minorly from Timnodonic
acid/Eicosapentaenoic /Omega 3 Fatty
acid
? During Eicosanoid Biosynthesis
Mostly
? Arachidonic acid is released by
Phospholipids Viz: Lecithin/PIP3
? By Phospholipase A2 activity
?Eicosanoids has very
short half life
?From seconds to few
minutes
Classification Of Eicosanoids
? Prostanoids : Obtained by
Cycloxygenase System :
?Prostaglandin
?Prostacyclins
?Thromboxanes
? Leukotrienes and Lipoxins are
obtained by Lipoxygenase System
Prostaglandins are Derivative of
Arachidonic acid
1. Prostaglandins (PGs)
? Prostaglandins are type of
Eicosanoids.
? PGs also termed as Prostanoids
? Since they are obtained from
parent compound Prostanoic
acid
Biosynthesis Of Prostaglandins
? Per day 1 mg of
Prostaglandins are
biosynthesized in human
body.
? Prostaglandins are derived
from Arachidonic acid by
Cycloxygenase system.
? Phospholipid Lecithin releases
Arachidonic acid
? Arachidonic acid is used for
Prostanoic acid synthesis.
? Prostanoic acid then
biosynthesizes Prostaglandin in
human body.
Structure and Types Of PGs
? Prostaglandin structure is complex
and possess:
?Cyclopentane ring
?Double bond
?Carboxylic and Hydroxyl groups
?Prostaglandins contains
a
?Cyclopentane ring with
Hydroxyl groups at C11
and C15
? Prostaglandins (PG) are of
fol owing Types:
?PG A
?PG B
?PG C
?PG D
?PG E
?PG F
?PG G
?PG H
Occurrence/Distribution Of PGs
Occurrence Of PGs
? Prostaglandin was first seen in
Prostatic secretion and Semen.
? Later it was found that
Prostaglandins are ubiquitous
? Present all over in human body
tissues.
Functions OF Prostaglandins
? Prostaglandins serve as Cell
Signaling Agents/Local
Hormones with.
?Paracrine in action (act on
sites closely where they are
produced/ neighboring cel s).
?Autocrine in action that the
sites where they are produced.
? PGs exert their function
through G-Protein linked
membrane receptors.
Prostaglandins have
diverse functions on
many tissues
?Action of one PG is
different in different
tissues.
?Sometimes PGs bring out
opposing action in same
tissue.
1.
4.
Regulate Blood
Inhibits Gastic secretion
Pressure
2.
5.
FUNCTIONS OF
Promotes Kidney
Help in Parturition
Prostaglandins
Function
3.
6.
Produces pain,
Bronchodilation
inflammation and Fever
1.Role Of PGs In Blood Vessels
PGs Regulate Blood Pressure
? PG A and PG E are Vasodilators.
? PGs lowers the blood pressure by:
?Increasing blood flow and
?Decreasing vascular resistance in
blood vessels.
? PGs are used Therapeutical y
in treating Hypertension.
Prostaglandin occur at
Platelets
Inhibits Platelet
Aggregation
and
Thrombus formation
2. PGs Has Role in Uterus At The Time
Of Parturition
? PG natural y increases
uterine contraction of
smooth muscles which
induces the delivery of baby.
? PGs can be therapeutical y used as
Abortificients during Medical
Termination of Pregnancies (MTPs).
? PGs also arrests postpartum
hemorrhage.
3. Role Of Prostaglandins In Lungs
? PGs in Lungs serve as
Bronchodilators and
Bronchoconstrictor of Lungs.
?PG E-Bronchodilator
?PG F- Bronchoconstrictor
?PG E is used in
treatment of Bronchial
Asthma.
4. Role Of Prostaglandin In GIT
? Prostaglandin in stomach
increases its motility and inhibits
gastric secretion of HCL.
? PG is used in treatment of gastric
ulcers.
5. Role Of Prostaglandins in Kidneys
? PGs in Kidneys increases GFR
and promotes urine formation
and urine out put.
? Thus helps in removing waste
out of the body.
PGs Regulate Sleep and Wake Process
? Use of PG D2 promotes Sleep
6.Effect Of PGs on Metabolism
? PGs Decreases Lipolysis (breakdown of
TAG).
? PGs increases Glycogenesis.
? PGs promotes Steroidogenesis
(Biosynthesis of Steroid hormones)
? PGs promotes mobilization of ionic
Calcium from bones.
Production of PGs
Promote
Fever , Pain , Nausea
Vomiting and Inflammation
Role Of PGs
In Immunity And Inflammation
? Prostaglandins are produced in more
amounts at the time of :
?Fever
?Pain
?Nausea and Vomiting
?Inflammation
? Provide non specific immunity to body
?PGs are more produced in
inflammatory disorders
like Rheumatoid Arthritis.
? Drugs like NSAIDs Aspirin used in
treating inflammatory disorders.
? Inhibits the Enzyme of
Cycloxygenase system
? Which in turn inhibits the
biosynthesis of Prostaglandins.
2. Prostacyclins (PGI2)
Prostacyclins (PGI2)
? Prostacyclins are type of Eicosanoids/
Prostanoids.
? Principally formed in vascular
endothelium
? They are Platelet Aggregation
Inhibition Factors
? Biosynthesized by enzyme Prostacyclin
Synthetase.
Roles of Prostacyclins
? Prostacyclins are Vasodilators.
? Prostacyclins like Prostaglandins
inhibit platelet aggregation.
? Prostacyclins prevent Thrombus/clot
formation.
3. Thromboxanes (TX)
Thromboxanes (TX)
? Thromboxanes are also termed as
Platelet Aggregating Factor (PAF).
? Thromboxanes are
Prostanoids produced by
Thrombocytes (platelets)
? By Enzyme Thromboxy
Synthase.
Structure Of Thromboxanes
?Thromboxanes possess a
cyclic Ether in their
structures.
Types Of Thromboxanes
? TX A and TX B are types of
Thromboxanes.
? TXA2 is more prominent in
human body.
Functions Of Thromboxanes
? Thromboxanes are vasoconstrictors.
? Thromboxanes enhances platelet
aggregation.
? Thromboxanes favors blood clot
formation during blood coagulation.
? Thromboxanes and Prostacyclins
are antagonistic to each other
balancing their activities.
? Increased Thromboxane activity
results in Thrombosis.
4. Leukotrienes
Leukotrienes
? Leukotrienes are type of
Eicosanoids
? Biosynthesized through
Lipoxygenase system in
Leukocytes.
? Leukotrienes are a family
of Eicosanoid
? They are Inflammatory
mediators produced
in leukocytes.
Structure And Types Of Leukotrienes
Leukotrienes Structure and Types
? Leukotrines are Hydroxy derivatives
possessing conjugated Trienes .
? Types of Leukotrienes:
? LTB4, LTC4, LTD4 and LTE4
Occurrence Of Leukotrienes
? Early discovery of
Leukotrienes was in
Leukocytes.
?Leukotrienes are also
produced and present in.
?Mast cells
?Lung
?Heart
?Spleen
Effect Of Leukotrienes
? Leukotrienes are biologically active
components of Slow Reacting
Substances (SRS-A).
? SRS-A are released during Al ergic
reactions/Anaphylaxis.
?Leukotrienes are 100-
1000 times more
potent than Histamine
during al ergic
reactions.
?LTB4 is a potent
chemotactic agent.
(chemical substance which
mediates movement of
cel s).
? Leukotrienes by action are:
?Bronchoconstrictors
?Vasoconstrictors
? LTC4, LTD4 and LTE4 are Slow -
Releasing Substance of
anaphylaxis ( SRS - A ) ,
? SRS-A causes fluid leakage from
blood vessels to an inflamed area.
Levels Of Leukotrienes Increased In
? Al ergies
? Al ergic rhinitis
? Asthma
( Tightening of airways, difficult to breathe)
?Overproduction of
Leukotrienes causes
Anaphylactic shocks.
?An Antiasthmatic drug
Prednisone inhibits
Leukotriene
biosynthesis.
5.Lipoxins
Lipoxins
? Lipoxins are Eicosanoids produced
in Leukocytes of human body.
Roles Of Lipoxins
Lipoxins are essential in maintaining tissue
homeostasis and resolve inflammation.
? Lipoxins are:
?Vasoactive/Vasodilators
?Anti-inflammatory
?Anti-proliferative
?Pro-resolving
?Immunoregulatory
?Chemotactic substances
Omega 6 and Omega 3 Derived
Eicosanoids
Are Opposite in Action
? Omega 6 Derived Eicosanoids
? Prostaglandins:
?Promotes Inflammation
? Omega 3 Derived Eicosanoids
Resolvins and Eoxins are:
?Anti inflammatory
?Anti allergy
?Anti hypertensive
?Anti cancer
?Anti atherosclerotic
Effects of Eicosanoids
? Local pain and irritation
? Bronchospasm
? Gastrointestinal disturbances:
nausea, vomiting, cramping,
and diarrhea.
Biological Actions of Selected
Eicosanoid Molecules
Generation of arachidonic acid metabolites and their roles in inflammation.
The molecular targets of some anti-inflammatory drugs are indicated by a red X.
COX, cyclooxygenase; HETE, hydroxyeicosatetraenoic acid;
HPETE, hydroperoxyeicosatetraenoic acid.
Amphipathic Lipids
Examples Of
Amphipathic Body Lipids
? Phospholipids
? Glycolipids
? Free Fatty acids
? Free Cholesterol
Features Of Amphipathic Lipids
? Structure has both polar and non polar groups
? Partial y soluble
? Orientation of groups:
?Polar group directed towards
water phase
?Non polar group directed in oil
phase/away from water.
Role Of Amphipathic Lipids
? Amphipathic Lipids have fol owing biological
Significances in forming:
? Biomembranes:
(Phospholipid bilayer, Glycolipids and Cholesterol)
? Emulsions:
? In intestine PL help in Lipids Digestion
? Micelles:
? In intestine help in Lipids Absorption
? Lipoproteins:
? For transport of nonpolar/neutral Lipids
? Liposomes:
? Agents for Drug /Gene carrier
Emulsions
Emulsions
? Emulsions are small droplets of
oils miscible in aqueous phase.
? Emulsions are usually formed by
Nonpolar and Amphipathic Lipids
along with Bile Salts in aqueous
phase.
In Human GIT
? Emulsions are formed as
smal , miscible dietary Lipid
droplets in aqueous phase of
intestinal juice in intestinal
lumen.
?Emulsions are formed
during the process of
Emulsification in GIT.
Requirements For Emulsification
? Emulsifying agents :
?Bile salts (Major)
?Amphipathic Lipids (Minor)
? Mechanical force aids
emulsification.
? Emulsifying agents reduces
surface tension.
? Emulsifying agents form a
surface layer of separating
main bulk of nonpolar Lipids
from aqueous phase.
?Emulsions are stabilized
by detergent action of
emulsifying agents.
Emulsification Process
? Emulsification process takes place in an
aqueous phase of intestinal juice in intestinal
lumen and forms Emulsions.
? During Emulsification Hydrophobic or
nonpolar dietary Lipids (TAG) are mixed with
an emulsifying agents:
?Bile salts
?Lecithin( Amphipathic Lipids)
? Mechanical force(provided by
intestinal peristaltic
movement) facilitates the
process of Emulsification.
Types Of Emulsions
I. Oil In Water
I . Water In Oil
Significance Of Emulsions
? Emulsions formed in the intestinal
lumen help in the digestion of dietary
Lipids.
? The dietary large droplets of Fat/Oil
are transformed to smal ,miscible
droplets as Emulsions.
? Emulsions bring the dietary
Lipids in contact with Lipid
digesting Enzymes present in
aqueous phase of intestinal
juice.
Micelles
? Micelles have a disc like shape .
? Critical concentration of Amphipathic
Lipids in aqueous medium form
Micel es(~200 nm).
? Bile salts help in forming Mixed
Micel es.
?Mixed Micel es are
formed in Intestine after
digestion of Lipids.
?By an aggregation of
various forms of dietary
digested Lipids with Bile
salts.
? Aggregation of various
digestive end products of
dietary Lipids covered with a
peripheral layer of Bile salts
form Mixed Micelles in
intestinal lumen.
? Mixed Micel es contain the
non polar Lipids in the
interior portions and polar
Bile salts on the exterior.
Significance Of Mixed Micel es
? Mixed Micelles helps in
absorption of dietary Lipids
? From intestinal lumen into
intestinal mucosal cel s.
Liposomes
? Amphipathic Lipids when exposed to
high frequency sound waves (Ultra
Sonication) in aqueous medium to
agitate particles and form Liposomes.
? Liposomes can be prepared by disrupting
biological membranes by ultra
sonication(>20 KHz )
Structures Of Liposomes
? Liposomes are composite structures made
of largely phospholipids and smal amounts
of other molecules
? Liposomes has spheres of one/ many Lipid
bilayers.
? Liposomes contain aqueous regions(polar
phase) and intermittently lipid bilayer (non
polar phase).
Types Of Liposomes
? Unilamellar Liposome
? Multilamellar Liposome
Applications Of Liposomes
? Liposomes are vehicles for
administration of drug through blood,
targeted to specific organs.
? Topical transdermal delivery of drugs.
? Transfer of Gene into vascular cells
? Water insoluble drugs are carried
in Hydrophobic region of
Liposome.
? Water soluble drugs are carried in
Hydrophilic region of Liposomes.
Biomedical Importances
Of Body Lipids
Roles of 7 Biomedical y Important Lipids
1. Fatty Acids (FAs)
2. Triacylglycerol (TAG)
3. Phospholipids (PL)
4. Lipoproteins (LP)
5. Glycolipids
6. Cholesterol (Free)Cholesterol-Ester(Esterified)
7. Eicosanoids (PGs,PGI,TX,LT,LX,Resolvin)
Body Lipids Functions
1.
Secondary Source of Energy
2.
Energy Storage Lipids- Long term use
3.
Thermal and Electrical Insulators
4.
Cushioning Effect and Shock absorber
5.
Shape and Contour to body
6.
Structural Lipids- Biomembrane components
7.
Cel antigens, receptors, anchoring sites
8.
Signal Transduction and Nerve Impulse conduction
9.
Lung Surfactant helps in normal respiration
10. Emulsifiers helps in Lipid digestion and absorption
11. Transport Lipids
12. Metabolic regulatory Lipids
1.
4.
Builds Membranes
Sources Of Energy, PUFAs
Signal Transmission
,Fat soluble Vitamins
2.
5.
Restores Abundant
FUNCTIONS OF LIPIDS
LUBRICATE
Energy
Cushioning Effect
3.
6.
Nervous Function
Electrical and Thermal
Lung Surfactant,
Insulators
Emulsifiers
Fatty acids of TAG is a
Source of Energy
Energy-Containing Nutrients (C and H)
H+
ATP Electron
Transport
Chain
CO2
O2
H2O
Good About Body Lipids
? Liberate 9 kcal per
? Regulates cell
gram of TAG.
function
? Major fuel at rest
? Maintains membrane
? Endurance Exercise
structure
? Source of :
? Improve nerve
function
?Essential fatty acids
? Provides flavors and
?Fat-soluble vitamins
textures of foods
? Gives satiety value
Disorders Associated To Lipids
? Obesity
? Atherosclerosis
? Respiratory Distress Syndrome
? Fatty Liver
? Hyperlipoproteinemias
? Hypolipoproteinemias
? Necrosis ,Oxidative damage of biomembranes due
to Lipid peroxidation
? Lipid Storage Disorders
Common
Lipids Associated Disorders
? Obesity
? Metabolic Syndrome
?Atherosclerosis
?Coronary Heart Disease
?Hypertension
?Diabetes Mel itus
Lipid Storage Disorders
Inborn Errors Of Lipid Metabolism
? Congenital Defects where
deficient of Enzymes
? Affects an Abnormal
accumulation of Lipid forms
? In cells and tissues affecting
there functionality.
S.No Lipid Storage Disorder Enzyme Defect and
Abnormal Accumulation of
1
Niemann Picks Disease Sphingomyelinase
Sphingomyelins
2
Gaucher's Disease
Beta Glucocerebrosidase
Glucocerebrosides
3
Krabbe's Disease
Beta Galactosidase
Galactocerebrosides
4
Tay Sach's Disease
Hexoseaminidase-A
Gangliosides
5
Farber's Disease
Ceramidase
Ceramides
S.N
Human body Lipids
Associated Disorders
Biochemical Defects Biochemical Alterations
01
Triacylglycerol
Obesity
Excess deposition of
Hyperlipidaemias
Metabolic syndrome TAG in Adipocytes and Hypertriglyceridemia
fatty Liver
Liver
Atheroma's
02
PUFA's
Phrynoderma
Deficiency of PUFA's
Hypolipoproteinemia
03
Cholesterol
Familial
LDL receptor defects
Atherosclerosis
hypercholesterolemia
Occlusions
Tissue Infarcts
04
Phospholipid
Respiratory distress
Low lung surfactant No reduction of surface
syndrome
tension of Alveoli
05
Lipoprotein
Hyperlipoproteinemias
LPL defects
Atherosclerosis
LDL defect
Occlusions
Tangier's disease
HDL defect
Tissue Infarcts
06
Lipidosis
a. Tay Sach's disease
Hexoseaminidase
Accumulation of
OR
Gangliosides
Lipid storage disorders
b. Niemann pick's
Sphingomyelinase
Accumulation of
disease
sphingomyelin
a. Gaucher's disease
Beta
Accumulation of
Glucocerebrosidase
Glucocerebrosides
a. Krabbe's diease
Beta
Accumulation of
Galactosidase
Galactocerebrosides
a. Farber's diease
Ceramidase
Accumulation of
Ceramides
Questions
? Long Answer Questions
? Define Lipids (Bloor's Definition).
Classify Lipids with suitable
examples.
? Define Fatty acids. Classify them
with different modes and suitable
examples.
? What are Compound lipids?
Describe Phospholipids wrt
Chemistry,Types,Nature,SourcesDi
stribution,Functions and
associated disorders of.
? What are Sterols? Describe the
structure, dietary sources,
properties & functions of
Cholesterol.
? Write Short Notes.
? Biomedical importance of various
forms of body Lipids
? Enlist various disorders associated to
Lipid forms with biochemical defect
and alterations.
? Essential fatty acids (PUFAs) & their
role in the body.
? Triacylglycerol/Neutral Fats- Structure
& Function.
? Rancidity- Causes & Prevention.
? Gycolipids/Cerebrosides/Gangliosides
? Lipoproteins- Chemistry, types &
functions
? Eicosanoids/Prostaglandins
? Therapeutic uses of Prostaglandins
? Distinguish between Fats & Waxes
? Nomenclature & Isomerism of fatty acids
? Omega 3 fatty acids and their importance
? Amphipathic nature of lipids and their roles
? Distinguish between Fats & Oils
? Enumerate biomedical important lipids with
their classes
? Properties of Fatty acids.
? Simple Lipids with their examples
? Enumerate Compound Lipids & one
function of each
? Name Derived lipids & their functions
? Trans Fats and their harmful effects
? Tests to check the purity of fats &
oils/Characteristic number of Fats
Revision Questions
? Define Lipids
? Number and Names of Lipid Classes
? Define Derived Lipids
? Examples of Derived Lipids
? Define Fatty acids
? What is Delta and Omega end of FAs
? What is Beta Carbon of a Fatty acid
? 6 Modes of Classification of Fatty
acids
? Fatty acids with one double bond is:--------------
? Name most predominant Fatty acid of human
body-----
? Most easily metabolized fatty acids are :----------
--,____________- and _____________
? Fatty acid with odd and even number carbon
atoms are:
? PUFAs are Fatty acids with---------------------
? Name PUFAs of Omega 3 and 6 types
? Enumerate Lipidosis with enzyme defects
? Are Nutritionally Essential Fatty acids and
PUFAs same
? Name branched Chain and Odd Number
Fatty acids
? Name Cyclic and Hydroxy Fatty acids
? What are Cis and Trans Fatty acids
? Enlist Omega 3 Fatty acids and 3 Main
Roles
? Criteria for Sub classification of Simple
Lipids
? Define Simple lipids
? Examples/Subtypes of Simple Lipids
? What is a Class of Fat/Oil and its chemical
name
? Define Waxes
? Name human body Wax
? Differences of Fats and Oils
? Differentiate between
Cerebrosides and Gangliosides
? Occurrence and Role of TAG
? Definition of Compound Lipids
? Types of Compound lipids
? Sphingophospholipid Example
? Number and Names Of
Glycerophospholipids
? Hormonal role of Phospholipds
? Chemical composition of Lung
Surfactant
? Which Compound Lipid is classified
under classes of Lipid and Protein?
? Enzyme defect in Niemann Picks Disease
? Red Spot Macula is noted in which all
conditions
? In which disorder Ceramides get accumulated
in joints
? Emulsions and Liposomes results due to which
Lipid forms.
? On what criteria's TAG is selected as reservoir
of energy for long term use
? Enumerate various Lipid Storage disorders with
biochemical defect and abnormal accumulated
Lipid form
? What value of L/S ratio shows lung maturity and
immaturity?
? What are components of Lung Surfactant?
? What are roles of Lung surfactant?
? What form of energy source helps in endurance of
exercises of body?
? Which Lipids are associated to biomembranes?
? What are applications of Amphipathic Lipids?
? What clinical conditions shows
Hypercholesterolemia?
? Enzymes associated for Eicosanoids biosynthesis.
? Therapeutic roles of Prostaglandins
Thank You
Biochemistry Department
This post was last modified on 05 April 2022