PHARMACOLOGY - Reproductive Pharmacology Flashcards
What can be used to treat infertility in female animals?
Synthetic GnRH or GnRH analogues can be used to treat infertility in female animals
How does synthetic GnRH or GnRH analogues treat infertility?
Synthetic GnRH or GnRH analogues induce a GnRH surge, LH pulses and thus ovulation in anovulatory females
How have GnRH analogues been modified to increase their potency?
GnRH analogues have been modified to increase their half-life as well as their affinity for GnRH receptors
Give two examples of potent GnRH analogues
Buserelin
Deslorelin
How can potent analogues actually cause eventual infertility?
Potent GnRH analogues will initially cause a flare effect (GnRH surge) followed by downregulation of GnRH receptors, leading to suppressed gonadal function and infertility
What is a common hormonal mechanism used to suppress testes function and cause infertility in male dogs?
Deslorelin implant
Why is the Deslorelin implant not used in intact bitches and queens?
The Deslorelin implant will cause the flare effect (GnRH surge) which will lead to ovulation and possible conception anyway. Deslorelin implant can also potentially lead to a pyometra
Give two examples of vaccinations that can be used to prevent reproductive activity in animals?
GnRH vaccination
Zona pellucida vaccination
How does the GnRH vaccination prevent reproductive activity in animals?
The GnRH vaccine leads to antibody production against GnRH causing GnRH to be metabolised before it can carry out its function, leading to suppressed gonadal function and suppressed fertility
How does the zona pellucida vaccination prevent reproductive activity in animals?
The zona pellucida vaccine leads to antibody production which bind to the ZP3 proteins on the zona pellucida, blocking sperm binding to these proteins and this inhibiting fertilisation
What are the two main benefits of the zona pellucida vaccine?
No side effects
No effects on social balance due to having no effect on sex steroid hormones
What can be used to manipulate oestrous cyclicity in female animals?
Progesterone or synthetic progestogens
Prostaglandin F2α (PGF2α)
Melatonin
What can be used to terminate pregnancies in large animals?
Prostaglandin F2α (PGF2α)
When during gestation can Prostaglandin F2α (PGF2α) be used to terminate the pregnancy?
Prostaglandin F2α (PGF2α) can only be used to terminate a pregnancy when the corpus luteum is the sole source of progesterone production
Why is Prostaglandin F2α (PGF2α) not commonly used to terminate bitch pregnancies?
The bitch corpus lutea are very unresponsive to prostaglandin F2α (PGF2α) and the high doses would be required to induce luteolysis and pregnancy termination which would lead to very unpleasant side effects
What can be used to terminate small animals pregnancies?
Progesterone receptor antagonists
Give an example of a progesterone receptor antagonist used to terminate small animal pregnancies?
Aglepristone
What can be used to induce parturition in animals?
Glucocorticoids
Prostaglandin F2α (PGF2α)
How do glucocorticoids induce parturition?
Glucocorticoid administration will imitate the foetal cortisol rise required to induce parturition
What can be used to stimulate myometrial contractions during parturition?
Oxytocin
How does oxytocin administration stimulate myometrial contractions?
Oxytocin stimulates the Ferguson reflex, stimulating myometrial contractions
When would you want to administer oxytocin to stimulate myometrial contractions?
Non-obstructive dystocia
Post partum haemorrhage
Uterine involution
Removal of retained placenta
What can be administered to stimulate the milk letdown reflex?
Oxytocin
What can be administered to relax myometrial contractions?
β2 adrenergic agonists
What can be administered to inhibit lactation and treat pseudopregnancy in bitches?
Prolactin receptor antagonists
Dopamine (D2) receptor agonists
