Chemistry and Pharmacology of sex hormones

Question 1

What is the common precursor of sex hormones

Answer 1

Cholesterol

Question 2

What are three sex hormones in the estrogens category, when are they expressed

Answer 2

Estradiol- expressed in ovaries of women during reproductive age , Estriol- expressed during pregnacny , Estrone- expressed during menopause in peripheral tissue

Question 3

What are the two main androgens, what enzyme converts one into the other

Answer 3

Testosterone and Dihydrotestosterone, 5-alpha reductase converts testosterone to dihydrotestosterone in peripheral tissues

Question 4

Where does biosynthesis of sex hormones start, what is released from this area

Answer 4

Hypothalmus, gonadotrophin

Question 5

What gonads create which sex hormone

Answer 5

Testes-tesosterone, ovaries- estrogen

Question 6

T/F: Gonadotropin Releasing Hormone (GnRH) is a neurohoromone converted from 92 amino acid peptide into a decapeptide

Answer 6

True

Question 7

How does GnRH get to its destination

Answer 7

Released from hypothalamic neurons to travel to the anterior pituitary gland using the hypophyseal portal system

Question 8

T/F: Lutenizing Hormone (LH) and Follicle-Stimulating Hormone (FSH) are heterodimers consisting of an alpha and beta subunit with identical beta subunits and different alpha subunits

Answer 8

False: LH and FSH are heterodimers consisting of an alpha and beta subunit with identical alpha subunits and different beta subunits

Question 9

What cells create tesosterone, which cells create estrone and estradiol

Answer 9

Leydig cells in males and Theca cells in females, Sertoli cells in males and granulosa in females

Question 10

What is the process for tesoterone formation in Leydig cells

Answer 10

LH binds to its receptor activating P450cc allowing LDL to enter the cell and be converted to pregnolone in the mitochondria, pregnenolone is converveted to progesterone and then testosterone in the endoplasmic reticulum

Question 11

What is the proccess for estrogen formation in sertoli cells

Answer 11

FSH binds to its receptor activating aromatase converting testosterone into estrogens

Question 12

T/F: Progesterone is a precursor to androgens (testosterone) and Estrogens

Answer 12

True

Question 13

In males what protien binds to testosterone to allow it to travel in the blood and keep it in high concentrations

Answer 13

Androgen Binding Protein

Question 14

How often do hormonal episodes happen in males

Answer 14

4 to 8 times in 24 hours

Question 15

T/F: GnRH is essential to maintain high concentrations of testosterone for spermatogenesis because it stimulates FSH and LH

Answer 15

True

Question 16

What happens when sperm leaves Sertoli cells

Answer 16

It is used to aid in maturity of sperm cells from spermatogenesis

Question 17

In the ovaries what releases estrogen, progesterone

Answer 17

granulosa cells of maturing ovary, corpus luteum

Question 18

What are the two stages that ovaries endure, what happens in each stage

Answer 18

Follicular stage- Ovum matures until it is released in ovulation, Luteal stage-

Question 19

Where are thecal cells, granulosa cells

Answer 19

Around maturing follicle, around maturing ovum

Question 20

T/F: Just like in males, in females only thecal cells can convert cholesterol into pregnelone and progesterone

Answer 20

False: In Females LH binds both thecal and granulosa cells to convert cholesterol into prenenolone and progesterone

Question 21

T/F: Just like in males FSH is needed to activate aromatase to convert testosterone into estrogens and this can only happen in the granulosa cells

Answer 21

True

Question 22

How is GnRH released in one month for women

Answer 22

GnRH levels are low in the beginning but get gradually higher as estrogen levels increase, High estrogen output leads to causes GnRH stimulation that leads to LH surge causing Ovulation, Estrogen progesterone and inhibin from Corpus luteum leads to decrease in GnRH and LH, Corpus luteum dies and progestrone drops considerably causing bleeding and the loop to happen all over again

Question 23

What are other souces of estrogens besides ovaries

Answer 23

liver, adrenal glands, breast, placenta, and fat

Question 24

What is the difference between genomic pathway and non-genomic pathway

Answer 24

Genomic: sex hormone binds to its receptor then dimerizes to enter nucleus and act as a transcription factor, non-genomic: sex horomone binds to its receptor then activates signaling pathways to influence gene expression