1. Pengaturan hormon: sistem reproduksi
Alfiah Hayati
Biologi, Unair

2. Spermatogenesis: Sperm Production in the Testis
Seminiferous tubules
Spermatids
Spermatocytes
Spermatozoa
Sertoli cells
Interstitial tissue
Leydig cells
Capillaries

3. Testicular Compartmentalization

4. Sertoli Cell

5. Sertoli Cells Function
Nourish healthy cells & phagocytize damaged germ cells
Synthesize luminal proteins
Maintain tubular fluid
Convert androgens to estrogens
Are site for hormonal modulation of tubular function

6. Spermatogenesis: Sperm Production in the Testis
Figure 26-9b-e: ANATOMY SUMMARY: Male Reproduction

7. Spermatozoa Structure and Functions
Head
Acrosome
Nucleus
Midpiece
Centrioles
Mitochondria
Tail: flagellum
Microtubules
Figure 26-10: Sperm structure

8. The blood-testis barrier: biology, regulation, and physiological role in spermatogenesis
The blood-testis barrier (BTB) in mammals (rats)  composed of:
the tight junction (TJ),
the basal ectoplasmic specialization (basal ES),
the basal tubulobulbar complex (basal TBC) (both are testis-specific actin-based adherens junction [AJ] types), and
the desmosome-like junction that are present side-by-side in the seminiferous epithelium

9. The BTB physically  divides the seminiferous epithelium into basal and apical compartments  spermatogenesis
The function:
an immunological barrier to segregate the postmeiotic germ-cell antigens from the systemic circulation,
it creates a unique microenvironment for germ-cell development

10. BTB restructuring to facilitate germ-cell migration is regulated:
During spermatogenesis  the BTB in rodents must physically disassemble to permit the passage of preleptotene and leptotene spermatocytes.
This occurs at late stage VII through early stage VIII of the epithelial cycle.
BTB restructuring to facilitate germ-cell migration is regulated:
two cytokines, namely transforming growth factor-beta3 (TGF-beta3) and
tumor necrosis factor-alpha (TNFalpha), via downstream mitogen-activated protein kinases

11. Cytokines determine the homeostasis of  TJ- and basal ES-structural proteins, proteases, protease inhibitors, and other extracellular matrix (ECM) proteins (e.g., collagen) in the seminiferous epithelium
Some of these molecules  regulators of focal contacts between the ECM and other actively migrating cells (macrophages, fibroblasts cells)
These cell-cell junction restructuring at the BTB  regulated the cell-matrix interface

12. in reproduction system
Hormone regulation:
in reproduction system

13. Male Sex Steroid Synthesis

14. Cholesterol  from plasma
Testosteron  in peripheral tissues  to estradiol & androstenedione
Androstenedione  source of estradiol in men

15. Major Testicular Steroids
() = Relative activity where T activity=100
Androgens are C19 steroids
Majority of 5 a-DHT is formed in peripheral tissues

16. Transport of Sex Steroids in Males
Major Sex Steroid Binding Proteins
Testosterone-Estrogen Binding Protein (T1/2=22 seconds) Sex steroids = DHT (100) >T (33) >E (25)
Albumin (T 1/2-=1 second)
Cortisol Binding Globulin (No binding to DHT, T or E2, but binds Progesterone)
Normal Distribution in Blood
TEBG (30%), Albumin (68%), Free (2%)
Active fraction includes free + albumin-bound fraction

17. Androgen Activity Increased Spermatogenesis Increased Bone Growth
Increased bone matrix, calcium deposition
Increased Nitrogen Balance
Increased muscle mass, larynx size

18. Androgen Activity Increased atheletic performance
Increased basal metabolic rate, red blood cell density oxygen utilization
Altered Skin Function
Increased thickness, melanin deposition sebaceous gland secretion

19. Androgen Activity (1) Androgen-Receptor Interactions
Both testosterone (T) and dihydrotestosterone (DHT) interact  androgen receptor
DHT has a higher affinity for the androgen receptor than T

20. Androgen Activity (2) T-Androgen Receptor Interaction
Feedback regulation of gonadotropin secretion
Differentiation of Wolffian duct
DHT-Androgen Receptor Interaction
External genitalia differentiation

21. Regulation of Spermatogenesis
GnRH  LH  Leydig cells  testosterone  sex charact
GnRH  FSH  Sertoli cells  spermatocyte maturation
Inhibin feedback – FSH  testosterone

22. Regulation of Spermatogenesis
Figure 26-11: Hormonal control of spermatogenesis

23. Testicular Cell Interactions

24. Testicular Cell Interactions
Sertoli cell products estradiol, inhibin, activin and other proteins modulate leydig cell activity
Sertoli cell products modulate germ cell function
Leydig cell testosterone modulate peritubular & Sertoli cell function
Peritubular cell products influence Sertoli cell activity

25. Hypothalamic-Pituitary regulation of Testicular Function

27. Oogenesis

28. Hypothalamus-Pituitary-ovary (1)

29. Hypothalamus-Pituitary-ovary (2)

30. Hypothalamus-Pituitary-uterine (1)

31. Hypothalamus-Pituitary-uterine (2)

32. Hypothalamus-Pituitary-uterine (3)

34. Thank you
very much