Reproduction (Yr 2) Flashcards
how can GnRH agonists be given to cause different effects?
given in pulses will stimulate FSH and LH release
given as continuous release will cause receptor down regulation and inhibit LH and FSH
what is the main function of GnRH agonists?
stimulate FSH and LH and hence ovulation
suppression of reproductive function using continuous release implants
what is the function of GnRH vaccines?
induces antibodies against GnRH to chemically castrate pigs
how are GnRH vaccines given?
two does of GnRH analogue-protein conjugate (vaccine) at least two weeks apart
what are the LH and FSH receptor agonists used in veterinary medicine?
PMSG/eCG (FSH)
hCG (LH)
what does the administration of gonadotropins (anterior pituitary hormones) do?
stimulate release of sex steroid hormone from testis and ovaries
when would PMSG be used?
to promote recruitment of follicles for superovulation programmes
when would hCG be used?
stimulate production of testosterone to determine if an animal is cryptorchid
what is the main use of progesterone receptor agonists?
inhibit GnRH release to prolong the luteal phase of the cycle for oestrus synchronisation programmes
what are oxytocin receptor agonists used for?
stimulation of uterine contraction to facilitate parturition in the presence of a fully dilated cervix
promote involution of post-parturient uterus
promote milk let down (mastitis…)
what are prostaglandin receptor agonists used for?
synchronisation programmes
induce abortion/parturition
what can melatonin be used for?
increase GnRH pulsatility and advance breeding season in sheep
what are beta2 adrenergic agonists used for?
relax uterus in cattle - dystocia, prolapse, caesarian, embryo transfer…
what is an examples of a beta2 adrenergic agonist?
clenbuterol
what are glucocorticoid receptor agonists used for?
mimic foetal cortisol surge to induce parturition or abortion
