GnRH

Gonadotroph Releasing Hormone

Source:

   Hypothalamic surge and tonic

   centers

Target:

   Anterior Pituitary(Gonadotroph cells)

Action:

   Causes release of FSH and LH

LH

Source:

Gonadotroph Cells (Anterior pituitary)

Target:

Male: leydig cells

Female: theca interna, luteal cells

Action:

Male:Stimulates testosterone Production

Female:Stimulates ovulation, formation of CL and progesterone secretion.

FSH

Follicle Stimulating Hormone

Source:

Gonadotroph cells (Anterior Pituitary)

Target:

Male: Sertoli cells (in testis)

Female: Granulosal cells (in ovaries)

Action:

Male: Sertoli Cell Function

Female: Follicular development and estradiol synthesis.

Prolactin

Source:

Anterior Pituitary (lactotroph cells)

Target:

Male: Testis and brain

Female: Mammary glands

Action:

Male: Can Induce maternal behavior

Female: Lactation, maternal behavior

Oxytocin

(OT)

Source:

Paraventricular Nuclei in hypothalamus. (stored in posterior pituitary)

Target:

Male: Smooth muscle of epididymal tail, ductus defrens, and ampulla

Female: Myometrium and endometrium, myoepithelial cells

Action:

Male: PGF_2α synthesis and pre-ejaculatory movement of sperm

Female: Uterine motility, promotes uterine PGF_2α synthesis, milk ejection.

Estradiol (E₂)

Source:

Male:Sertoli cells

Female: Granulosa cells of follicle and placenta

Target:

Male: Brain

Female: Hypothalamus, reproductive tract and mammary glands

Action:

Male: Sexual Behavior

Female: Sexual behavior, GnRH release, elevated secretory activity of entire tract, and uterine contraction (estrus)

Progesterone (P₄)

Source:

Female: Corpus Luteum, Placenta

Target:

Female: Endometrium, myometrium, mammary glands, hypothalamus.

Action:

Female: Endometrial secretion, inhibits GnRH release, inhibits reproductive behavior, promotes maintenance of pregnancy

Testosterone (T)

Source:

Male: Leydig interstitial cells

Female: Theca Interna

Target:

Male: Accessory sex glands, scrotum, seminiferous epithelium, skeletal muscles

Female: Brain, Skeletal muscles, granulosal cells.

Action:

Male: Anabolic growth, promotes spermatogenesis, promotes secretion of accessory sex glands

Female:Substrate for E₂ synthesis, abnormal masculinization (hair patterns, voice, behavior,etc)

Inhibin

Source:

Male: Sertoli Cells (Testes)

Female: Granulosa cells (ovary)

Target:

Hypothalamus

Action:

Inhibit FSH production without inhibiting LH production.

PGF_2α

Source:

Male:Vesicular gland

Female: Endometrium

Target:

Male:Epididymis

Female:Corpus luteum, Myometrium, ovulatory follicules

Action:

Male: Affects metabolic activity of spermatozoa, causes epididymal contractions

Female:Luteolysis, promotes uterine tone and contraction, ovulation

PGE₂

Source:

Ovary, uterus, embryonic membranes

Target:

Female:CL, oviduct

Action:

Female: Ovulation, Stimulates CL secretion of progesterone.

TRH

Thyrotropin Releasing Hormone

Source:

Hypothalamus

Target:

Anterior pituitary

Action:

Cause release of TSH and prolactin

CRH

Corticotropin Releasing Hormone

Source:

Hypothalamus

Target:

Anterior Pituitary

Action:

Causes release of ACTH

GHRH (or SRH)

Growth Hormone Releasing Hormone

(or Somatotropin Releasing Hormone)

Source:

Hypothalamus

Target:

Anterior Pituitary

Action:

Cause release of GH

Somatostatin

Source:

Paraventricular nuclei of the hypothalamus

Target:

Anterior Pituitary

Action:

Inhibits release of GH

ACTH

Adrenocorticotropic Hormone

Source:

Anterior Pituitary

Target:

Adrenal Cortex

Action:

Cortidosteroids from the adrenal gland (affects metabolism)

TSH

Thyroid Stimulating Hormone

Source:

Anterior Pituitary

Target:

Thyroid

Action:

• Stimulates release of thyroxine (T₄)
• Stimulates release of triiodothyronine.

STH (or GH)

Somatotropin Hormone

(Growth Hormone)

Source:

Anterior Pituitary

Target:

All cells in body

Action:

Bone Growth and muscle accretion, Lactation (females)

Relaxin

Source:

CL during pregnancy

Target:

Uterus and cervix, Pelvic ligament

Action:

Cervical dilation Pelvic ligament stretch