VPT 311: General and Systemic Veterinary Pharmacology (2+1)

ANTERIOR PITUITARY GONADOTROPHINS

• Both LH and FSH are glycoprotein hormones.
• They are secreted from the gonadotroph cells o f the anterior pituitary gland.
• They consist of two polypeptide subunits.

Effects

• The gonadotrophic hormones control the estrous cycle of the female and modulate testicular functions in the male.
• In the female, FSH is responsible mainly for growth of the follicle by binding to granulosa cells and stimulating estradiol production.
• LH is responsible for final maturation and ovulation by binding to the thecal cells of the developing follicle and stimulating the synthesis of androgens.
• In the male, LH binds to leydig cells or interstitial cells located in the connective tissue stroma of the testis and stimulate androgen production.
• The gonadotrophins are available as a powder which can be easily reconstituted by the addition of sterile water, saline or appropriate buffer.
• Once in the liquid form they must be stored at 4 degree centrigrade and not subjected to excessive agitation to prevent denaturation of protein.

Uses

• The uses of LH are
  • to induce ovulation of a mature follicle
  • to leutinize follicular cysts
  • to induce follicular growth and ovulation.
• The uses of FSH are :
  • to increase the number of ova shed in the cattle for superovulatory purpose and
  • to increase the litter size by increasing the ovulation.