LEC 3 - Reproductive Drugs - Males Flashcards
What type of hormone are gonadotropins?
Glycoprotiens
How do gonadotropins compare across species?
Identical alpha subunits
Different beta subunits
What are the gonadotropins?
FSH
LH
CG
What is the specific prostaglandin in reproduction?
PGF2alpha
Where are the steroid reproducive hormones produced?
Throughout the reproductive tract
GOnads
Uterus/placenta
Hypothalamus
What are the characteristics of the steroid reproductive hormones?
Short 1/2 lives
Long duration of action
What is the characteristic of the GnRH cycle?
Plasma GnRH concentrations oscillate with peaks occurring every 60 to 90 minutes
What does GnRH (from the hypothalamus) stimulate to happen in the anterior pituitary?
LH + FSH secretion
What does LH from the anterior pituitary do?
Stimulate interstitial cells
Secrete testosterone
What does FSH from the anterior pituitary do?
Stimulate seminiferious tubules
Sustentacular cells
Secrete Inhbin
What does inhibit from the seminiferous tubules do?
Inhibits secetion of FSH
What does testosterone from the interstitial cells do?
Inhibit GnRH secretion
Intersitital cells aka
Leydig cells
Sustentacular cells aka
Sertoli cells
What are the two main uses for chorionic gonadotropin in males?
Correction of cryptorchidism
Determination of remnant testicualr tissue in castrated cats/dogs
What are the hormones that control testicular descent?
Insulin-like GF 3
Anti-mullarian Hormone
Adrogens
When an animal is given hCG where does it act?
Interstitial cells
When does hCG have to be given inorder to aid in cryptorchisism?
during time of proper decent
first 8 weeks of life
How is GnRH administered?
Digested in GI tract
So given IM
How is human chorionic gonadotropin adminstered?
Digested in GI tract
IM adminstration
How is hCG handled in the body?
Metabolized by the liver
To testes in males
To ovaries in females
What are the adverse reactions to hCG?
Hypersensitivity reaction
(due to being from humans)
How is hCG used to deteremine whether there is any remnant testicular tissue?
Draw blood
Give hCG/GnRH
Wait 60 to 90 minutes
Measure T = should be constant in castrated animal
What is recommened for medical treatment in cases of benign prostatic hyperplasia in breeders?
Finasteride
– and –
Progestin
Where does finasteride act in cases of benign prostatic hyperplasia?
5alpha - reductase
Where do progestins act in cases of benign prostatic hyperplasia?
5alpha - dihydrotestosterone
How is finasteride given?
PO
How is finasteride handled by the body?
Metabolized by the liver
90% bound to plasma proteins
What does finasteride have interactions with?
Anticholinergics
What does finasteride do to hormone levels?
Lowers DHT but not testosterone
Reduces prostatic diameter
What are the two progestins?
Medroxyprogesterone acetate
Megestrol acetate
What is the progestin used in vet medicine?
Megastrol acetate
How is megaestrol acetate handled by the body?
Absorbed in the GI tract
Fully metabolized by the liver
Whats improtant to note when handling progestins?
females need to be careful
Increased risk of mammary/uterine cancers
Fetal abnormalities
