Chemistry and Pharmacology of sex hormones Flashcards
(24 cards)
What is the common precursor of sex hormones
Cholesterol
What are three sex hormones in the estrogens category, when are they expressed
Estradiol- expressed in ovaries of women during reproductive age , Estriol- expressed during pregnacny , Estrone- expressed during menopause in peripheral tissue
What are the two main androgens, what enzyme converts one into the other
Testosterone and Dihydrotestosterone, 5-alpha reductase converts testosterone to dihydrotestosterone in peripheral tissues
Where does biosynthesis of sex hormones start, what is released from this area
Hypothalmus, gonadotrophin
What gonads create which sex hormone
Testes-tesosterone, ovaries- estrogen
T/F: Gonadotropin Releasing Hormone (GnRH) is a neurohoromone converted from 92 amino acid peptide into a decapeptide
True
How does GnRH get to its destination
Released from hypothalamic neurons to travel to the anterior pituitary gland using the hypophyseal portal system
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
False: LH and FSH are heterodimers consisting of an alpha and beta subunit with identical alpha subunits and different beta subunits
What cells create tesosterone, which cells create estrone and estradiol
Leydig cells in males and Theca cells in females, Sertoli cells in males and granulosa in females
What is the process for tesoterone formation in Leydig cells
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
What is the proccess for estrogen formation in sertoli cells
FSH binds to its receptor activating aromatase converting testosterone into estrogens
T/F: Progesterone is a precursor to androgens (testosterone) and Estrogens
True
In males what protien binds to testosterone to allow it to travel in the blood and keep it in high concentrations
Androgen Binding Protein
How often do hormonal episodes happen in males
4 to 8 times in 24 hours
T/F: GnRH is essential to maintain high concentrations of testosterone for spermatogenesis because it stimulates FSH and LH
True
What happens when sperm leaves Sertoli cells
It is used to aid in maturity of sperm cells from spermatogenesis
In the ovaries what releases estrogen, progesterone
granulosa cells of maturing ovary, corpus luteum
What are the two stages that ovaries endure, what happens in each stage
Follicular stage- Ovum matures until it is released in ovulation, Luteal stage-
Where are thecal cells, granulosa cells
Around maturing follicle, around maturing ovum
T/F: Just like in males, in females only thecal cells can convert cholesterol into pregnelone and progesterone
False: In Females LH binds both thecal and granulosa cells to convert cholesterol into prenenolone and progesterone
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
True
How is GnRH released in one month for women
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
What are other souces of estrogens besides ovaries
liver, adrenal glands, breast, placenta, and fat
What is the difference between genomic pathway and non-genomic pathway
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
