Ovarian Steroidogenesis
Contents
Ovarian steroids are produced from all except
A. Stroma
B. Luteinised cells
C. Theca cells
D. Zona Pellucida
Granulosa cells produce all except
A. Follistatin
B. AMH
C. Androstenedione
D. IGF- II
All are true of AMH except
A. Strongly correlate with the number of growing follicles
B. AMH expression is enhanced in follicles >8 mm
C. In men, AMH is secreted from the Sertoli cells
D. Down-regulate the aromatizing capacity of granulosa cells
The principal androgens secreted by ovary are
A. Dehydroepiandrosterone and Androstenedione
B. Androsterone and Etiocholanolone
C. 17-α-hydroxyprogesterone and Androstenedione
D. Testosterone and Androsterone
Not true of peptide hormone release from ovary
A. Follistatin – Granulosa cells
B. Inhibin A – Theca lutein cells
C. AMH- granulosa cells of primordial follicles
D. IGF-II – Theca cells
Not true of ovarian steroidogenesis
A. Excess insulin may promote increased ovarian androgen production
B. Progesterone may play an important role at the time of ovulation
C. Follicular fluid contains less amounts of SHBG
D. AMH levels fluctuate minorly during normal menstrual cycles
In Shorts
- In the menstrual cycle, the mid-cycle surge of gonadotropins (both luteinising hormone [LH] and follicle-stimulating hormone [FSH]) signals the initiation of the periovulatory interval.
- During the ovulatory phase the follicle augments progesterone production and begins to luteinise, ultimately leading to the rupture of the follicle wall and the release of an oocyte.
- Relaxin is secreted from the preovulatory follicle and corpus luteum. It probably facilitates follicular rupture during ovulation.
- In natural cycles, the concentration of progesterone in the follicular fluid at the time of the LH surge is very high compared with that of oestradiol. The timing of the increase in progesterone levels is important for endometrial development
- The administration of gonadotropins in controlled ovarian stimulation (COS) leads to supraphysiological steroid concentrations of a very different profile compared with those seen during natural cycles. These high steroid concentrations cause alterations in endometrial development, affecting oocyte viability in assisted reproductive technology.
