The document discusses the role of prostaglandins (PGs) in reproductive health, including their chemistry, biosynthesis, and physiological roles in both female and male reproductive systems. It outlines the involvement of PGs in processes such as ovulation, labor, menstruation, and various pathological conditions like dysmenorrhea and endometriosis. Clinical uses of PGs in obstetrics are also highlighted, particularly in cervical ripening and labor induction.

1. ROLE OF PROSTAGLANDINS IN
REPRODUCTIVE HEALTH
•GROUP 4
•PRESENTER: DR. FATUMA. M. SALAA
MEMBERS: DR. DAISY BOR, DR. CHRISTINE ONTIRIA,
DR. SYDNEY LUVAYO, DR.THIRIKWA GATHECA
Facilitator: Dr Kagema

2. OBJECTIVES
• Definition
• Chemistry & Nomenclature
• Biosynthesis
• Function and Source
• Physiological role in Female and Male reproductive system
• Role in pathological conditions in reproductive health
• Clinical uses

3. DEFINITION
• Prostaglandins are a group of
physiologically active compounds
generated enzymatically from Fatty
acids notably Arachidonic acid.

4. CHEMISTRY&NOMENCLATURE
CHEMISTRY: prostaglandins are 20- carbon carboxylic acids with
a cyclopentane ring which are formed from polyunsaturated
fatty acids.
NOMENCLATURE: Specific prostaglandins are named with a
letter (which indicates the type of ring structure) followed by a
number (which indicates the number of double bonds in the
hydrocarbon structure). For example, prostaglandin E1-series
1 is abbreviated PGE1and prostaglandin I2 - series 2-is
abbreviated PGI2.

5. BIOSYNTHESIS

6. FUNCTION OF PGS
• They have the property of acting as “local hormones”
• They sustain homeostatic function.
• They mediate pathological mechanisms including the inflammatory
response.
• Effects: vasodilation, vasoconstriction, stimulation of intestinal or
bronchial smooth muscle, uterine stimulation

7. SOURCE
ENDOGENOUS: Identified in the following:
FEMALE REPRODUCTIVE SYSTEM
Endometrium
Decidua and Amniotic membrane
Menstrual fluid
MALE REPRODUCTIVE SYSTEM
Seminal fluid

8. PHYSIOLOGICAL ROLE OF PGS
IN THE FEMALE REPRODUCTIVE
SYSTEM
• Ovulation
• Implantation
• Menstruation
• Labor

9. OVULATION
3 major phases in which PGs may be involved
a. Follicular maturation
b. Follicular rupture
c. Corpus luteum degeneration

10. IMPLATATION
• Prostaglandins participate in each stage of the interaction of the embryo
with the endometrium, for example in preimplantation, implantation
(apposition, adhesion/attachment, invasion/penetration) and
decidualization; as well as affecting many other cells and molecules.
• PGs have a complex role in each of these stages, e.g., the essential role
of prostaglandin E2 (PGE2) in the oocyte is to enhance the cumulus
expansion in ovulation for sperm penetration, to regulate extracellular
matrices disassembly, and also, importantly, to participate during
transport and embryo implantation.
• PGE2 maintains luteal function for embryo development and early
implantation. In addition, it induces chemokine expression for
trophoblast apposition and adhesion to the decidua for implantation.

11. FALLOPIANTUBE MOTILITY
Fallopian tubes can synthesise these PGs locally
PGE2
• Cause relaxation
• Suppresses its activity during & after ovulation
PGF2 a
• Causes contraction (facilitates ovum transport to the uterus)
PGI2
• Causes relaxation

12. MENSTRUATION
Different actions in the endometrium & myometrium
They affect blood flow in 3 different ways
• Direct effect on vascular smooth muscle-via PG receptors
• Increase in uterine tone or contractile activity-mechanical compression of
uterine arteries( PGE & PGF2 a)
• Potentiation/Depression of adrenergic neurotransmission ( PGE & PGF2
a )
• They alter local neurogenic release of norepinephrine from presynaptic
nerve terminals
• They modify responsiveness of postsynaptic nerve terminal to NE

13. MENSTRUATION
PGF2 a
• myometrial contraction (increase uterine contractility &
tone)
• Vasoconstriction (reduces uterine blood flow-ischemia
& menstrual flow ensues
PGE2
• Myometrial contraction
• Vasodilatation-increase in uterine blood flow
• Promotes platelet aggregation

14. MENSTRUATION
PGI2 (Prostacyclin)
• produced by endothelial cells
• Myometrial relaxation
• Vasodilatation
• Inhibits platelet activity-increased menstrual blood flow
NOTE: Elevation of Estrogen levels just before ovulation
stimulates PG activity which in turn produce their
vasoactive effects-mainly vasodilatation leading to increased
uterine blood flow.

16. LABOR
PGE2
• induces labor with cervical effacement and dilatation.
• It shortens induction to delivery interval.
• PGs promote myometrial contraction irrespective of the duration of
gestation, whereas oxytocin acts predominantly on the uterus at term or
in labor.
• Myometrial contraction (PGF2 more potent) Increased receptors of
PGE2, PGF2a and in turn increased sensitivity of myometrium to
oxtocin.
• Reduce Progesterone receptors (PGF2a)
• Placental separation
• Uterine involution (PGF2a)

17. Around term,
Increased Prostaglandin concentrations in Amniotic fluid
Increased COX expression in chorion
Increased sensitivity to PGs
Reduced PGDH activity more so in area of chorion laeve covering the
cervix. Usually high during pregnancy

18. • The parent fatty acid for omega-6 is linoleic acid (LA) and the parent fatty acid for omega-3
is -linolenic (ALA) acid.
α
• Both are essential Fatty acids. LA is converted to the biologically active omega-6 fatty acid,
arachidonic acid (AA), which is involved in cell-signaling pathways and functions as a
precursor for proinflammatory eicosanoids. ALA is converted to the biologically active
omega-3 fatty acid, EPA, which, in turn, is converted to the omega-3 fatty acid, DHA. DHA is
the critical component of cell membranes in the brain and retina, where it is involved in
visual and neural function as well as neurotransmitter metabolism.
• Omega-9 fatty acids represent one of the main mono-unsaturated fatty acids (MUFA) found
in plant and animal sources. They are synthesized endogenously in humans, though not
fully compensating all body requirements. Consequently, they are considered as partially
essential fatty acids. MUFA represent a healthier alternative to saturated animal fats and
have several health benefits, including anti-inflammatory and anti-cancer characters.
RELATION OFTHE OMEGAS(3,6,9) TO PROSTAGLANDINS

19. • Diets that are balanced in both omega-6 and omega-3 may be less
inflammatory and immunosuppressive.
• A high ratio of omega-6 to omega-3 fatty acids will result in
increased proinflammatory eicosanoid production (ie,
prostaglandin E2 [PGE2] and prostaglandin F2α [PGF2α]). These
metabolites have been associated with the initiation of labor and
preterm labor.
• Including more EPA in the diet may lead to a reduction in the
production of proinflammatory eicosanoids and increased
production of prostacyclin (PGI2), which may promote
myometrial relaxation. Omega-3 fatty acids downregulate the
production of prostaglandins PGE2 and PGF2α, and may thereby
inhibit the parturition process.

20. The hypothesis that dietary supplementation of omega-3 fatty acids
could prevent preterm birth originated from studies conducted in the
Faroe Islands.31
Compared with the diet in Denmark, the population of
the Faroe Islands has a higher intake of marine foods, and babies born
to these women have higher birth weights (about 200 g) at term. In
fact, birth weights of babies from the Faroe Islands are higher than
those in 33 other countries.31
A number of randomized, controlled trials have attempted to validate
these findings, but with variable results. Four randomized, controlled
trials have demonstrated either a reduction in the rate of preterm
birth or an increase in the average length of gestation in either
primary or secondary analysis
Source:Pubmed:https://www.ncbi.nlm.nih.gov/pmc/articles/
PMC3046737/

21. MALE REPRODUCTIVE SYSTEM
• . PGs, above all PGE, occur in testicle tissue, have a
modulating effect on the LH-dependent steroid
synthesis and possibly influence sperm density and
sperm function. The PGs certainly play a part in the
motility of the vas deferens and participate
decisively in blood flow regulation in male genitals.
• The seminal vesicle synthesizes very large amounts of PGs,
which probably display their action in the semen plasma and
with this also in the female genital tract

22. MALE REPRODUCTIVE SYSTEM
• Smooth muscle relaxing prostaglandins such a PGE1
enhance penile erection by relaxing the smooth muscle of
the corpora cavernosa- Alprostadil used clinically in the
Diagnosis and second-line treatment of erectile dysfunction
due to vascular, psychological, or neurological etiologies.
• Men with a low seminal fluid concentration of PGs are
relatively infertile.

23. PATHOLOGICAL IMPLICATION OF
PGS
• Dysmenorrhea
Many of these patients have an increased synthesis of prostaglandins in their
endometrial tissue with increased prostaglandin release in the menstrual fluid.
The increased amount of prostaglandins induces incoordinate hyperactivity of
the uterine muscle resulting in uterine ischemia and pain.
NSAIDS such as ibuprofen, naproxen, flufenamic acid, mefenamic acid and
indomethacin are capable of relieving primary dysmenorrhea.These drugs are
inhibitors of the prostaglandin synthetase enzymes which are necessary for
prostaglandin biosynthesis.Thus, with ibuprofen it has been shown that clinical
relief of the dysmenorrheic symptoms accompanies the reduction of
menstrual fluid prostaglandins

24. PATHOLOGICAL IMPLICATION OF
PGS
• Endometriosis
Prostaglandin E(2) is up regulated in the peritoneal cavity in
endometriosis and is produced by macrophages and ectopic
endometrial cells. This abnormal prostaglandin production leads to
increased dysmenorrhea and early pregnancy losses in
endometriosis
PGE2 controls many critical functions, such as steroidogenesis,
angiogenesis, proliferation, and immune suppression that
contribute to the pathogenesis of endometriosis.

25. PATHOLOGICAL IMPLICATION OF
PGS
• Male Infertility
• Erectile Dysfunction

26. CLINICAL USES OF PGS IN
OBSTETRICS
• Cervical ripening prior to induction of labor or abortion.
• Induction of labor
• Augmentation of labor
• Management of Atonic Postpartum hemorrhage
• Termination of Molar pregnancy.
• Medical managent of tubal ectopic pregnancy

27. PREPARATIONS
PG E2- is available in the following forms:
Vaginal tablet-
Vaginal pessary
Gel- Prostin E(Dinoprostone)
PGE1-
Methyl ester of PGE1- Misoprostol
Note: Misoprostol is cheaper and stable at room temp unlike the
above PGE2

29. REFERENCES
• PUBMED
• DUTTA TEXTBOOK OF OBSTETRICS
• FIGO GUIDELINES ON INDUCTION OF LABOR