Reproduction, Marie Nováková1
PHYSIOLOGY OF REPRODUCTION
2
Life is a dynamic system with focused behavior, with
autoreproduction, characterized by flow of substrates,
energy and information.
Reproduction, Marie Nováková
3
Reproduction in mammals (humans)
1) Sexual reproduction
2) Selection of partners
3) Internal fertilization
4) Viviparity
5) Eggs, resp. embryos – smaller, less, slow development, placenta
6) Low number of offspring, intensive parental care
High investment, low-volume reproduction strategy !
Pregnancy (days)
Mouse 20
Rat 23
Rabbit 31
Dog 63
Cat 65
Lion 107
Pig 114
Sheep 149
Human 260 - 275
Cow 285
Rorqual 360
Elephant (Indian) 609
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Reproduction in humans – gender comparison
1) Both male and female are born immature (physically and sexually)
2) Differentiation of reproduction organs during prenatal period
3) Hypothalamus – adenohypophysis – gonads in both gender, the same signals (hormones)
4) Different productin of sex hormones during prenatal and perinatal periods
5) Reproduction period (puberty - menopause) significantly differs
6) Character of hormonal changes significantly differs – cyclic vs. non-cyclic
Reproduction, Marie Nováková
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• Meiosis occurs only in germ cells and gives rise to male and female GAMETES
• Fertilization of an oocyte by an X- or Y-bearing sperm establishes the zygote´s
GENOTYPIC SEX
• Genotypic sex determines differentiation of the indifferent gonad into either an OVARY or
a TESTIS
• The testis-determining gene is located on the Y chromosome (testis-determining factor,
sex-determining region Y)
• Genotypic sex determines the GONADAL SEX, which in turn determines
PHENOTYPIC SEX (fully established at puberty)
• Phenotypic differentiation is modified by endocrine and paracrine signals (testosteron,
DHT, AMH)
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INDIFFERENT GONAD week
XY XX 6.
medulla cortex
SERTOLI CELLS CELOM GRANULOSIS 7.
LEYDIG CELLS MESENCHYME THECA 8.
SPERMATOGONIA GERM.EPITH. OOGONIA 9.
AMH
m W M w 10.
T
SEX DIFFERENTIATION
Non-disjunction, mosaic. Examination (amniocenthesis, biopsy of chorioid.tissue).
Genetic male Genetic female
testes-determining gene (SRY)
Wolffian duct
(epidydimis, vas deferens)
Mullerian duct (tuba uterina, uterus)
AMH!!!
RATIO A/E
T a AMH affect internal genitalia in unilateral way (inner gene)
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AMH (MIH, MIF, MIS, MRF) – ANTIMŰLLERIAN HORMONE
1940, TGF- receptor with internal TK activity
Source: Sertoli cells (5th prenatal week) or embryonal ovary (36th prenatal week)
In adult women – granulosa cells of small follicles (NO in antral – under influence
of FSH - and atretic follicles)
Role in men:
• Regression of müllerian duct
• Marker of central hypogonadism
Role in women:
• Lower plasmatic levels (by one order), till menopause
• Estimation of ovarian reserve (AMH level corresponds to pool of pre-antral
follicles)
• Marker of ovarian functions loss (premature menopause)
• Diagnosing of polycystic ovaria syndrome
TUMOUR MARKER
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CRITICAL DEVELOPMENTAL PERIODS
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Vybrané kapitoly z fyziologie, GRADA, 2022
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CRITICAL DEVELOPMENTAL PERIODS
Late puberty
Critical body mass (critical amount of adipose tisssue/nutritional state)
Puberty
Adrenarche
•Pubarche
•Gonadarche
•Spermarche
•Telarche
•Pubarche
•Menarche
Pubertas praecox (central – gonadoliberin-dependent)
Pseudopubertas praecox (peripheral - gonadoliberin-independent)
Reproduction, Marie Nováková
11 Vybrané kapitoly z fyziologie, GRADA, 2022Reproduction, Marie Nováková
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Vybrané kapitoly z fyziologie, GRADA, 2022
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LEPTIN AND REPRODUCTION
Activation of reproductive system does not depend on age, but on nutritional state of organism.
LEPTIN: ob-protein, ob-gen, 7.chromosome
„“ = thin, slim
polypeptide, 176 AA
Bound in hypothalamus: n.paraventricularis, suprachiasmaticus, arcuatus a
dorsomedialis
Produced in: adipocytes, placenta, mammal epithelium (???)
Leptin plasmatic levels are sex-dependent (less in males) and do not depend on
nutritional state
Leptin receptor: gene on 4.chromosome, 5 types of receptor, A-E
Receptor B – effect in gonads and hypophysis
Leptin is not only a factor of body fat amount, but affects also the regulation of
neuroendocrine functions, including hypothalamo-hypophyseo-gonadal axis.
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Effects of leptin on testes are not fully elucidated yet.
Testosterone and dihydrotestosterone suppress production of leptin in adipocytes!
REGULATION OF PUBERTY ONSET BY LEPTIN
Critical body mass (critical nutritional state).
Leptin plasmatic levels in pre-pubertal children are sex-independent.
Pre-pubertal „leptin resistance“ (relative).
In puberty, girls produce 2x more leptin per 1kg of adipose tissue than boys.
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ncl. arcuatus
area preoptica - reproduction
Critical amount of adipose tissue – leptin – hypothalamus – LHRH – puberty
Reproduction, Marie Nováková
16 Pinilla et al., Phys Rev 92: 1235- 1316, 2012
KISSPEPTIN
- Increased expression of KISS1 gene
- Increased synthesis of kisspeptin
- Increased sensitivity of GnRH neurones to kisspeptin
- Pulsatory GnRH secretion …….
+
- Secretion of GH
- Decreased secretion of melatonin
PUBERTY
ncl. arcuatus
- Peptide, 54 AA
- Regulation of the puberty onset
- Control of GnRH secretion
- Produced also in placenta, syncytiotrophoblast, cytotrophoblast,
decidua
- Released together with neurokinin B and dynorphin
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BIOSYNTHESIS OF STEROID HORMONES
CHOLESTEROL
PREGNENOLON DEHYDROEPIANDROSTERON
PROGESTERON ANDROSTERON
CORTIKOSTERON TESTOSTERON
CORTIZOL
ALDOSTERON ESTRADIOL
ACTH
LH
LH
AT II.
FSH
chol.desmolase 17--hydroxylase
3--dehydrogenase
21-−−hydroxylase
ald.synthase aromatase
cortex of suprarenal glands gonads
PUBERTY
DHT
(5-reductase)(inhibition-treatment of alopecia)
(lack in hermaphrodites; inhibition-treatment of endometriosis)
Impact of androgens on CNS!
Reproduction, Marie Nováková
Adrenarche
PROLAKTIN
18
GONADOLIBERIN (GnRH, GONADOTROPIN-RELEASING HORMONE)
Control of gonadotrophins release - FSH, LH
Changed GnRH pulse frequency during the cycle
Reproduction, Marie Nováková
- Decapeptide, neurones in ncl. arcuatus, inputs from limbic
system and other part of CNS related to emotions, smell and stres
- Pulsatory secretion (glycosylation)
- Receptor coupled to G-protein: gonadotrophs in
adenohypophysis, lymphocytes, mamma, ovaries, prostate
- (GnRH-I, GnRH-II, (GnRH-III))
- Stimulation of secretion: kisspeptin, dopaminergic system in
CNS, leptin
- Inhibition of secretion: dominating inhibitory effect of gonadal
hormones with exception of estradiol (negative-positive-negative
feedback), malnutrition (FA, glu), lactation (PRL), seasonal
effect, aging, continual GnRH administration + gonadostatin
(neuropeptide suppressing LH, FSH, reproductive functions and
behaviour)
Acute stress – impairment (of cycle) without effect on fertility
Chronic stress – impaired fertility, decreased levels of circulating sex hormones
19 Reproduction, Marie Nováková
- Heterodimeric glycoprotein
- Subunit alpha common for FSH, LF, TSH, hCG, subunit beta LH specific
- Pulsatory secretion
- Level of glycosylation affects biological half-time
- Structure similar to hCG
- Receptor coupled to G-protein: all ovarian cells, Leidig cells, uterus,
semenné váčky, prostate, mamma, skin, suprarenal gland, thyroid gland,
retina, neuroendocrine cells
- Regulation of secretion: GnRH
GONADOTROPHINS
LUTEINIZING HORMONE (LH)
FOLICULES STIMULATIONG HORMONE (FSH)
- Heterodimeric glycoprotein
- Subunit alpha common for FSH, LF, TSH, hCG, subunit beta FSH
specific
- Pulsatory secretion
- Level of glycosylation affects biological half-time
- Receptor coupled to G-protein: granulosa cells, Sertoli cells,
endometrium (in secretory phase)
- Regulation of secretion: GnRH, oestrogens, activin, inhibin, follistatin
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ADDITIONAL REGULATION OF GONADOTROPINS SECRETION (LH)
Reproduction, Marie Nováková
Activins = regulation of transcription
Inhibins and follistatin = inhibition of activins by binding on their receptor
Produced in gonads and also in CNS, suprarenal glands, medulla.
Inhibins
– heterodimeric glycoprotein ( + A or B)
- produced in women in hypophysis, ovaries and placenta, in
men in Sertoli cells
- negative feedback on FSH production
– inhibin A
– inhibin B (testes)
Activins
– dimeric proteins similar to inhibin, activin A, B, AB
– stimulation of FSH production
– autocrine / paracrine factors
– important role in early stages of pregnancy
Follistatin
– glycoprotein
– inhibition of activin
- intragonadal autocrine/paracrine regulator
- expressed mainly in adenohypophysis
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FSH and LH - functions
FEMALES
FSH
- Growth and development of follicular cell
(maturation)
- Biosynthesis of estradiol
- Regulation of inhibin synthesis during follicular phase
- Upregulation of LH receptors (preovulatory
follicles)
- Selection of dominant follicle
- Recruitment of follicles for next cycle
LH
- Stimulation of oestrogen synthesis at various levels
(theca)
- Oocyte maturation (preovulatory follicle)
- Rupture of ovulatory follicle, ovulation
- Conversion of follicle wall to corpus luteum
MALES
LH
Intratesticular synthesis of testosterone (Leydig cells)
FSH
Spermatogenesis (Sertoli cells)
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PROLACTIN - PRL
- Protein
- Lactotropic cells (only PRL)
- Mammosomatotrophic cells (PRL and GH)
- Hyperplasia – pregnancy and lactation
- Expression regulated by oestrogens, dopamine, TRH and thyroid
gland hormones
- PRLR – mamma, adenohypophysis, suprarenal gland, liver,
prostate, ovary, testis, small intestine, lungs, myocardium, SNS,
lymphocytes
Regulation of secretion
- Pulsatile secretion: 4 – 14 pulses/day
- Highest levels during sleep
- Lowest levels between 10:00 and 12:00
- Gradual decrease of secretion during aging
- STIMULATION: TRH, serotonin, melatonin, oxytocin +
stress, starving, coitus, pregnancy, pharmacological
substances
- INHIBITION: dopamine
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MAIN FUNCTION: Milk production during pregnancy and lactation
= „survival“ function
PROLAKTIN AFFECTS PRODUCTION OF KISSPEPTIN.
Other functions – metabolic, synthesis of melanin, maternal behaviour
Breast development a lactation
- Puberty – mamma development under the effects of GH a IGF-1
- Effect of oestrogens and progesterone
- Age of 8 – 13
- During pregnancy – proliferation of alveoli and proteosynthesis
(proteins of milk and colostrum)
- During the 3rd trimester – production of colostrum (PRL, oestrogens,
progesterone, GH, IGF-1, placental hormones)
- Lactation – increase in PRL post-partum, without sucking drop after
approx. 7 days
- Milk accumulation prevents further PRL secretion
Reproductive function of PRL
- Lactation = amenorrhea and secondary
infertility
- Inhibition of GnRH secretion
PROLACTIN - functions
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REGULATION OF SEX HORMONES SECRETION – simplified scheme
HYPOTHALAMUS
ADENOHYPOPHYSIS
GONADS
GnRH
dopamine (PIF) opioids noradrenalin
FSH LH
Activin
Inhibin B
n.arcuatus
gonadoliberin
E P T
PROLACTIN
Pre-pubertal block of GnRH
Blocking the effects of gonadotrophins
Down-regulation of LH receptors in testes
and ovaria
Stress
Exercise
Seasonal variation
Nutritional state
GABA kisspeptin leptin
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MALE REPRODUCTION SYSTEM
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TESTOSTERON PRODUCTION:
•Embryonic – sex differentiation, development of generative organs
•Perinatal – descensus testis (?)
•Fertile period – LH pulsation
•Ageing – decrease of sensitivity to LH
FSH LH
SERTOLI CELLS LEYDIG CELLS
INHIBIN B TESTOSTERON
AMH
ACTIVIN DHT
ABG
Aromatase
(conversion of testosterone to estradiol)
GnRH
glycoproteins
HUMOURAL CONTROL OF REPRODUCTIVE FUNCTIONS IN MAN
-
-
-
PROLACTIN
5-reductase
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27 Reproduction, Marie Nováková
28 Reproduction, Marie Nováková
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SPERMATOGENESIS
Leydig cell
Capillary
Basal membrane
Spermatogonium
Tight junction
Spermatocyte
Spermatide (haploid)
Sertoli cell (contraction)
Spermia
70 days
1-64 (6 divisions)
Temperature<35°C
Acrosom (enzymes)
Head (nucleus, DNA)
Body (mitochondria)
Flagella (microtubules, 9+2)
Lumen:
androgens, estrogens
glutamate, aspartate
inositol
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PRODUCTION OF SPERM
SEMINIFEROUS TUBULES
SPERMATOGONIA SPERM 2 months
SERTOLI CELLS ABG temperature
LEYDIG CELLS radiation
EPIDYDIMIS maturing, motility 14-21 days
VAS DEFERENS storing months
SPERMATOCYSTS fructose
fibrinogen
prostaglandins
PROSTATE Ca2+, profibrinolysin
SPERM
T
Ejaculation:
3-4 ml
108 sp / ml (season)
pH = 7.5
motility (3mm/min)
Relaxin – improves motility of spermatogonia
Relaxin
FSH
FSH
LH
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Volume 1,5 - 2,0
pH 7,2 - 8,0
Concentration of sperm 20 mil/ml
Total number of sperm 40 mil and more
Motility 50% and more in category A+B, above 25% in A
Morphology 30% and more of normal forms
Vitality 75% and more of living sperm
Leukocytes up to l mil/ml
Autoaglutination < 2 (scale 0 - 3)
SPERMIOGRAM
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SEXUAL REFLEXES
CNS cortex, limb. system sexual behaviour
sexual agitation
nn.pudendales mechanoreceptors stimulation
nn.erigentes corpus cavernosum erection
gl.bulbourethralis lubrication
pl.pelvicus epidydimis, vas def.
sem.ves., prostate emission
m.bulbocavernosus ejaculation
trigonum vesicae ur. constriction
PARASYMP.
SYMP.
Sacral
spinal
cord
(glans penis)
(Ach, VIP)
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FEMALE REPRODUCTION SYSTEM
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OOGENESIS
DEVELOPMENT 6-8 weeks GERMINAL EPITHELIUM
Hormonally OOGONIA FOLLICLE
independent mitotic division PRIMORDIAL
24 weeks OOCYTES I. 7 x 106
1. meiosis
birth prophase 2 x 106
Hormonally puberty OOCYTES II. 3 x 105
dependent haploid DOMINANT
(cyclic) 2. meiosis ATRETIC
metaphase GRAAF
OVUM OVULATION
2. meiosis – end
menopause 0
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35
Daan and Fauser, Maturitas 82
(2015) 257–265
Reproduction, Marie Nováková
36 Daan and Fauser, Maturitas 82 (2015) 257–265
RECRUITMENT
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37 Pavel Trávník: Klinická fyziologie lidské reprodukce, GRADA, 2022.
290 DAYS 60 DAYS
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OVARIAN CYCLE
Germinal epithelium
Primordial Primary Graaf Corpus haemorrhagicum C. luteum
follicle
25 150 up to 2 cm
estradiol progesteron
Oocyte-maturation inhibiting factor
Vesicular
follicle
Luteinisation inhibiting factor
(estrogens)
(progestins)
OVULATION
methrorhagia
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CYCLIC CHANGES
ovarian
uterine
GnRH
FSH, LH
estradiol
basal temper.
0 4 14 28
MENS. PROLIPHER. SECRETORY PHASE
+
_
0.5 – 0.75°C
FOLICULLAR OV. LUTEAL PHASE
6-10x
2-3x
progesteron
+ vagina/cervix uteri
+ mamma
Reproduction, Marie Nováková
40 Pavel Trávník: Klinická fyziologie lidské reprodukce, GRADA, 2022.
A = LH peak
B = ovulation
FSH
estradiol
progesteron
LH
Opioids!!!
Reproduction, Marie Nováková
10-12 hrs
41 Pavel Trávník: Klinická fyziologie lidské reprodukce, GRADA, 2022.
Granulosaluteine
cell
Thecaluteine
cell
androgens
estradiol
progesterone
inhibin A
LH
Blood capillary
Reproduction, Marie Nováková
42 Pavel Trávník: Klinická fyziologie lidské reprodukce, GRADA, 2022.
LH
basal temperature
progesteron
A = LH peak
B = ovulation
Reproduction, Marie Nováková
43
VESICULAR FOLLICLE
PRIMARY FOLLICLE - FSH
Growth acceleration of primary follicle – change into vesicular follicle:
1) estrogens released into follicle stimulate granul. cells
UP REGULATION of FSH receptors and intrinsic positive feedback (higher
sensitivity for FSH!!!)
2) UP REGULATION of LH receptors (estrogens and FSH) – another
acceleration of growth due to „higher sensitivity“ to LH (positive feedback)
3) Increased estrogens and LH secretion accelerates growth of theca cells,
secretion is increased
explosive growth of follicle
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DOMINANT FOLLICLE
1. High levels of oestrogens from the fastest-growing follicle
2. Negative feedback on FSH production from adenohypophysis
3. Gradual decrease in FSH secretion
4. „Dominant follicle“ continues in growing due to intrinsic positive feedback
5. Other follicles grow slowly and subsequently become atretic
Reproduction, Marie Nováková
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MECHANISMS OF OVULATION
LH
PROGESTERON
Hyperaemia of follicle
Secretion of prostaglandins
Weakening of follicle wall
PROTEOLYTIC ENZYMES
(collagenases from theca externa)
Degeneration of stigma
Rupture of follicle
Release of oocyte
Transudation of plasma into follicle
Swallowing of follicle
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HUMOURAL REGULATION OF THE CYCLE
GnRH GnRH GnRH
FSH
LH
FSH
LH
FSH
LH
Follicular phase Ovulation Luteal phase
P FSH-rec. LH-rec. P P
P
A E A E A E A E
90´ 360´
GnRH
FSH
LH
30´
Artesia of follicle (but one!) Feedback -/+/- Involution of corpus luteum
Reproduction, Marie Nováková
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EFFECTS OF OVARIAN HORMONES
E P
Secondary sexual signs + Adipose
tissue: store (predilection), (critical amount) Bone
tissue: absorption closure
of fissures development
of pelvis Total
water retention: + +
Sexual behaviour: + Ovaries:
maturation of follicles
Hysterosalpinx: motility motility
Uterus: proteosynthesis proteosynthesis
vascularisation and proliferation of endom. secretion of endom. glands
EXCITATION glycogen
RELAXATION
Cervix: colliquation of „plug“ creation of „plug“
Vagina: cornification of epithelium proliferation of epithelium
Mamma: growth of terminals growth of acines
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PREGNANCY, PARTURITION, LACTATION
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FERTILISATION PROCESSES
COAGULATION
OF SPERM
LYSIS
20´
CAPACITATION
1 – 3 hours
vagina
pH
viability of sp.
1-3 days
hysterosalpinx
cervix uteri
prostaglandines
hyaluronidase
Spermatozoa: 108
103
10
motility of sp.
3 mm/min
fertilization 1
1. Chemoattraction
2. Fixing of spermia on zona pellucida
3. Penetration and acrosomal reaction (acrosin)
4. Fusion (fertilin, membr. potential change)
Syncytiotrophoblast, cytotrophoblast; decidua; implantation
Immune changes in pregnancy
(polymorfic MHC genes of class I., II. vs. non-polymorfic HLA-G).
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Ganong´s Review of Medicial Physiology
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HORMONAL PROFILE
DURING PREGNANCY
I. II. III. trimester
hCG
P E
PROL
Relaxin
hCS
OX
0 10 20 30 40 weeks of pregnancy
STH
TSH
ACTH
INS
KORT
ALD
T4
PTH
Placental – maternal – foetal source of hormones
Corpus luteum graviditatis
hCG, hCS, E, PE, P, Relaxin
(8th week!!!)
luteinisation and luteotropic effects
inhibition of myometrial contractions
preparation of lactation
growth hormone in pregnancy
induction of parturition
Placenta
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RELATIONSHIP BETWEEN P:E IN PREGNANCY
P E
P > E E > P
MOTHER PLACENTA FOETUS
cholesterol pregnenolone DHEAS
16OH-DHEAS
progesterone cortisol
aldosterone
DHEAS estradiol
Estriol
Foetal-placental unit
Excretion of estriol in urine
– index of foetal status
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Peptide Hormones and Neuropeptides
hCG
Thyrotropin (thyroid-stimulating hormone [TSH])
Placental-variant growth hormone
hCS1 and hCS2, also known as hPL (hPL1 and hPL2)
Placental proteins PP12 and PP14
TRH
Corticotropin-releasing hormone (CRH)
Growth hormone–releasing hormone (GHRH)
GnRH
Substance P
Neurotensin
Somatostatin
Neuropeptide Y
ACTH-related peptide
The inhibins
Steroid Hormones
Progesterone
Estrone
Oestradiol
Estriol
Reproduction, Marie Nováková
HORMONES PRODUCED BY PLACENTA
54
PHYSIOLOGICAL CHANGES DURING PREGNANCY
Changes of reproduction organs
• Uterus
– Growth (from 60 g to 1000 g), change of position
– Hyperaemia
– Functional differentiation of myometrium
• Cervix
– Changes of colour, consistency; shortening
– Hypertrophy a hyperplasia of glandules – mucus
plug
• Vagina
– Changes of colour, increase of secretion
• External genitals
– Vascularization, vasocongestion (changes of
colour)
Somatic changes
• Breasts
– Growth – alveolar as well as ductal part
– Enlargement and hyperpigmentation of
mammillae and areolas
• Skin
– Increase in subcutaneous fat
– Changes in connective tissue
– Hyperpigmentation
Endocrine and metabolic changes
Immunological changes
Psychic changes
Reproduction, Marie Nováková
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ENDOCRINE and METABOLIC CHANGES DURING PREGNANCY
Endocrine glands
• Thyroid gland
– Slight hypertrophy (E), increase in
thyroxine production, in III. trimester
BEE +25%
• Parathyroid glands
– Increase in production of
parathormone
• Adrenal glands
– Increase in production of aldosterone
• Pancreas
– Hyperplasia of Langerhans islets
Anterior pituitary gland
Metabolism
• Weight gain: 12-15 kg
• Glycaemia
– Glc – main energetic source for foetus
– Prohyperglycemic state
– Decrease of renal glucose reabsorption,
increase in glomerular filtration - glycosuria
– Gestational diabetes
• Increased demand for Ca (1300 mg), P
(1200 g) and Fe (18 mg/day)
• Water retention: + 6.5 l
Reproduction, Marie Nováková
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OXYTOCIN
- Mechanoreceptors/tactile receptors
- Magnocellular neurons (PVN, SON)
- inhibition by endogenous opioids, NO, GABA
- Autocrine (+ ZV)
- Prolactin, relaxin (-), Estrogens (+)
- OXT receptors (Gq/11) – effect of up/down regulation
- Acts together with prolactin and sex hormones
Functions
- Lactation (under 1 min) – MILK EJECTION
- Parturition
- rhythmical contractions of smooth muscles (gap-junction,
stimulation of prostaglandin synthesis – extracellular matrix)
- postpartum bleeding
- uterus involution
- Ejaculation (males)
- Behavior
Other functions and places of synthesis
- CNS
- Stimulation of ACTH secretion through CRH
- Stimulation of ADH/induced vasoconstriction
- Stimulation of prolactin secretion
- Memory traces recollection inhibition
- Maternal behavior
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57
– 9 AA, differs from ADH in the 3. and the 8. AA
– Precursor molecule is synthetized in the same location as ADH (nucleus
paraventricularis)
– Stimulus for synthesis: dilatation of birth path caused by pressure of foetus
and stimulation of mechanoreceptors at breast nipple
– Reflex release: during breast-feeding, orgasm
– Main effects – on reproduction system:
• Uterokinetic effects (induction of parturition), milk ejection, involution
of uterus
• In men: probably increases contractions of smooth muscle in ductus
deferens
– Regulation of water and mineral metabolism – natriuretic effect, potentiation
of ADH effect
– Effect on memory: opposite to ADH effect – inhibits forming of memory
and its recollection
OXYTOCIN
Reproduction, Marie Nováková
- OXT receptors (Gq/11)
- Myoepithelial cells
- Myometrium
- Endometrium
- CNS
- PLC, IP3, Ca2+
- Target molecule – MLCK (myosin light
chain kinase)
58
INDUCTION OF PARTURITION
P > E E > P
maternal
placental
foetal
CHOLESTEROL HT
ACTH OXYTOCIN
DHEA
PREGNENOLONE
CRH
EP
CORTISOL
PG
oxyt.rec.
conexin
gap-junctions
collagenase afferentation from mechanoreceptors
100x
Foetal respiratory insufficiency
Reproduction, Marie Nováková
Critical role of prostaglandins
59
LACTATION
GnRH PIF PSF OX.
GH
FSH
LH
PROL.
GCPH
UTERUS
involution
MAMMA
E HCSP
ejection
milk production
stop of
cycle
Composition of milk: water (88%), fat (3,5%), lactose (7%), proteins (1%)
trace minerals (Ca), vitamins, antibodies
(hyperprolactinaemia)
placental hormones
0.6-2 l/day
1 – 3 days after birth; initiated by decrease of oestrogens´ concentrations post partum
Reproduction, Marie Nováková
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LEPTIN AND REPRODUCTIVE FUNCTIONS
LEPTIN IN PREGNANCY
Synthesised by placenta from the 18th week of pregnancy.
Dramatic increase in maternal blood after the 34th week.
Synthesis in placenta, foetal adipose tissue and growing maternal adipose tissue.
BUT leptin plasmatic levels in non-pregnant women do not correspond to adipose
tissue amount (BMI).
Decrease after delivery down to the levels typical for non-pregnant women.
Leptin may play a role in proliferation and function of trophoblast, and thus affects
foetal growth.
LEPTIN IN NEWBORNS
Plasmatic levels of leptin correspond to newborn body mass and BMI.
Blood of newborn contains maternal and foetal leptin.
Girls have higher levels of leptin than boys.
It is supposed, that sex differentiation of plasmatic levels of leptin is already
genetically given, since it is not affected postnatally by sex hormones.
Reproduction, Marie Nováková