Hormonal Therapy Flashcards
what are prostaglandins?
20-carbon atom derivatives of fatty acids arachadonic acid and di-homo-gamma-linolenic acid
what does PGF2alpha do?
luteolytic
causes regression of corpus luteum
where is GnRH released?
hypothalamic surge and tonic centers
where is oxytocin stored?
posterior lobe of pituitary
what are the two components of luteinizing hormone and follicle stimulating hormone?
alpha subunit: identical
beta subunit: changes in each
what is alizin/aglepristone?
progesterone antagonist
when should you monitor estrus after giving a prostaglandin injection to a cow?
2-6 days after
is prostaglandin an effective drug for short-cycling sows?
no: CL not responsive until days 12-14 and naturally lyses at day 15
what would you use to suppress estrus in a mare?
altrenogest/regumate (brand for horses)
alternative brand for sows, same drug
how would you stimulate onset of first estrus in prepubertal gilts?
PG600
boar exposure
travel
combination
what can you use to synchronize estrus in weaned sows?
check for heat 4-6 days post weaning
triptorelin
based on weaning time
what can you use to sychronize estrus in pubertal and cyclic gilts?
progesterone
PG600
GnRH
triptorelin
is a single dose of prostaglandin effective at inducing abortion in a mare after day 40?
no
endometrial cups have been formed
what are thee biochemical classifications of hormone therapy?
peptides
glycoproteins
steroids
prostaglandins
which drugs are neuropeptides?
GnRH
oxytocin
what are the glycoproteins?
FSH
LH
eCG/PMSG
hCG
AMH
what do prostaglandins play a critical role in?
ovulation
passage of early embryo through oviduct
intrauterine migration of conceptus during maternal recognition of pregnancy- mare
cervical relaxation and uterine contraction during parturition
which prostaglandins are important in reproduction?
PGF
PGE
PGF2alpha luteolytic: regression CL
what are steroid hormones derived from?
cholesterol
where are steroid hormones produced?
adrenal cortex and gonads
which steroid hormones are responsible for sexual promotion?
estrogen
progesterone
testosterone
what is regu-mate/altrenogest?
synthetic progestin
what is melengestrol acetate used for?
growth promoting feed additive cattle
estrus suppression heifers for slaughter or breeding management
what are some problems with megestrol acetate?
irritating when injected
may induce endometrial hyperplasia/pyometra in bitch/queen
decreases resistance to bacteria and closes cervix: may lead to metritis
exacerbates mammary tumors in bitch
mastitis
what is GnRH released by?
hypothalamic surge and tonic centers
where is oxytocin synthesized?
posterior lobe of pituitary
what is the main side effect of GnRH/deslorelin?
injection site swelling
what is triptorelin acetate/GnRH used for?
intravaginal use for weaned sows for single fixed time AI
what do you need to have uterine effects of oxytocin?
estrogen priming prior to oxytocin
not in mares
are FSH and LH antigenic?
yes
what are LH and FSH available as?
pituitary, serum, urine extracts
what is human chorionic gonadotropin/
LH analog used for LH activity
glycoprotein hormone
what is a brand name of human chorionic gonadotropin?
PG600
what is porcine pituitary-derived follicle stimulating hormone?
glycoprotein hormone
only FSH product approved by FDA
from swine pituitary, usually has LH contamination
what does a progesterone antagonist do?
competitive antagonism of progesterone and blocking the hormone responsible for implantation and pregnancy maintenance
how can you terminate a pregnancy in a sheep?
cloprostenol or dinoprost before 55 days (CL maintains until 50-60 days)
dexamethasone after 55 days
what can you give a cow to induce parturition?
dexamethasone
flumethasone
