1. By
H.Khorrami Ph.D.
http://khorrami1962.spaces.live.com
khorrami4@yahoo.com

4. Prolactin
 By lactotrop cells (20% in both sexes)
 A single chain polypeptide hormone
 199 AA
 3 disulphide bridges
 Half life:20-30min
 Single gene on chromosome 6
 More than 300 effects
 Mostly by modulation

5. Prolactin
 Biologically active
 Immunoreactive
 Some patients with hi prolactin has no galactorhea

6. Prolactin
 Little 22000mw
 Big 50000mw lower activity
 Big-big 100000mw lower activity
 Glycosylated 25000mw

7. Prolactin actions
 Stimulate learning
 Stimulate immune responses
 Reduce body temperature
 Stimulate corticosteroid secretions
 Testosterone productions
 Maintain LH receptors

8. Prolactin stimulate transcription of mRNA of
 Casein
 Lactalbumin
 Beta-lactoglobulin
 Galactosyl transferase
 N-acetyl lactosamine synthetase

10. Prolactin inhibitors
 Dopamine from arcuate nucleus & VMN
 On D2 receptor
 Decrease cAMP
 Blocked by estrogen
 Blocked by phenothiazine or metoclopramide
 GnRH-associated peptide
 Histamine(H2)
 Diphenhydramine((H1blocker)
 GABA
 SST
 Ach
 Bromocryptine

11. PIF
 Dopamine
 GnRH-associated peptide

13. Prolactin stimulators
 TRH  Angiotensin II
 Oxytocin  Bombesin
 VIP  Secretin
 ACTH  Gastrin
 Beta-LPH  Galanin
 Estrogen  Calcitonin
 GnRH  Melatonin
 GHRH  Platelet-activating F
 Histamine(H1)  Epidermal GF
 Cimethidine(H2antagonist)  α-MSH

14. Prolactin increases with
 Puberty (female)  Feeding
 Pregnancy  Exercise
 Near the term 10fold  Stress
 Puerperium  Hypoglycemia
 Nursing  Surgical stress
 In fetus higher than  Orgasm(10fold)
mother near the term  Nocturnal sleep
 Neonate 2-3 week after
birth

16. Plasma prolactin concentration during & after dopamine
infusion in normal male/female subjects

17. Effect of L-dopa on PRL secretion

19. Serum PRL & cortisol in normal fasting volunteers before
& after regular mixed meal or sham*
*Seeing and chewing

20. Acute elevation of PRL after sleep

22. Prolactin levels in pregnant women

23. Lactation
1. Mammogenesis
 Estrogen, Progesterone
2. Lactogenesis
 Estrogen, Progesterone, prolactin, Placental lactogen,
Growth hormone, Insulin, Cortisol, T3, T4
3. Galactopoiesis
 Prolactin, oxytocin
 Estrogen increase the number of lactotropes

25. Relaxin and prolactin on myometrial activity

26. Hyperprolactinemia effects
 Stimulate dopamine turnover in some brain areas
 Nucleus accumbens
 Decrease dopamine turnover in some brain areas
 Substantia nigra
 Stimulate learning
 Stimulate immune response
 Stimulate oxytocin
 Stimulate opioidergic system
 Decrease gonadotropins
 Decrease testosterone in male(indirect)
 Decrease libido in both sex (impotence)
 Reduce bone mineral density (osteoporosis)

27. Hyperprolactinemia
 Is more frequent in girls with:
 Father absent
 Alchoholic father
 As a psychosomatic reaction
 Pseudopregnancy

28. This is MARS
But we have one EARTH yet!