lesson 70 Drugs Used in Reproduction

This set of flashcards covers the glossary of drugs used in reproduction, including their functions and applications.

GnRH Analogs

Induce estrus and synchronize ovulation in cattle, mares, and companion animals by stimulating the pituitary release of gonadotropins.

Follicle-Stimulating Hormone (FSH)

Employed in superovulation protocols to promote the development of multiple ovarian follicles.

Human Chorionic Gonadotropin (hCG)

Mimics the luteinizing hormone (LH) surge to trigger ovulation and support corpus luteum formation.

Equine Chorionic Gonadotropin/Pregnant Mare Serum Gonadotropin (eCG/PMSG)

Mimics FSH action and stimulates follicular development.

Prostaglandin F₂α Analogs

Induce luteolysis to regress the corpus luteum, synchronizing estrus cycles in cattle and other large animal breeding systems.

Progestins

Controls the estrous cycle by either maintaining or suppressing cyclicity; used for estrus synchronization and in pregnancy management across various species.

Oxytocin

Promotes uterine contractions during parturition and aids in postpartum milk letdown, critical for both large and small animal obstetrical management.

Dexamethasone

Utilized to induce parturition (especially in cattle) and to reduce inflammation within the reproductive tract; requires careful dosing to avoid adverse effects.

Melatonin

Regulates seasonal reproductive cycles by modulating the photoperiodic response, particularly in species such as sheep and goats that are seasonal breeders.

Cabergoline

Reduces prolactin secretion, beneficial in managing reproductive disorders—such as persistent corpus luteum issues or abnormal lactation—in various species.

HPG axis

GnRH analogues

Gonadorelin, Buserilin, Deslorelin

GnRH analog role in reproduction

increases LH/FSH secretion→ follicular development and ovulation

GnRH usage

used in cattle for follicular regulation.

used in mares and bitches for estrus induction and ovulation

What else can GnRH treat besides ovulation induction

ovarian cysts, follicular cysts via LH release→ luteinization of cyst contraception via downregulation receptors

clinical use of gonadotropins (FSH/LH)

superovulation-multiple dominant follicles form in cattle and small animals

induction estrus in anestrus bitches and queens

considerations for gonadotropin usage

prolonged use leads to adverse effect like cystic endometrial hyperplasia

FSH and LH mechanism

-follicular development and estrogen production

and

-triggering ovulation

Human Chorionic Gonadotropin (hCG)

mimics LH, promotes ovulation and support luteal function

hCG usage

in mares for breeding

diagnostic stimularion to test testicular function (cyrptorchidism test)

Diagnostic usage hCG

take pre and post sample after injection and measure testosterone plasma lv. peak lv is expected within 6 hours

Prostaglandin

induces luteolysis and dissolves/regression corpus luteum→ lowers Progesterone levels allowing estrus cycle to reset

prostaglandin drugs

cloprostenol, dinoprost, tromethamine

prostaglandin usage in reproductive management

synchronize estrus cycles in cattle and other farm animal

pregnancy termination

progestins

controls estrous cycle and maintain pregnancy

contraceptive—> inhibits LH surge to prevent ovulation

estrus synchronization→ insert for couple days then remove→ surge or GnRH=increase LH and FSH

estrogens

induce estrus and treat ovarian dysfunction

risk of steroid hormones (progestins and esrtogens)

custic endometrial hyperplasia

in estrus synchronization protocol for cattle progestins are typically used to

extend the luteal phase to control cycle timing

progestins drugs

melengesrtol acetate-MGA

Controlled interal drug release device-CIDRs used to prevent ovulation and when removed synchronizes estrus follows

oxytocin

stimulate uterine contraction during parturition, promote milk letdown during lactation

glucocorticoid