In vivo steroidogenic effects of homologous pituitary ventral lobe extract in the spiny dogfish, Squalus acanthias.

Academic Article


  • Pregnant Squalus acanthias were injected intravenously with aqueous extract equivalent to three pituitary ventral lobes (VL). Blood samples were withdrawn by caudal sinus puncture at intervals over a period of 72 hr and plasma progesterone, testosterone, and estradiol-17 beta measured by radioimmunoassay. Early pregnancy animals (Stage A) failed to respond, but mid-pregnancy animals (Stage C) responded to VL with significant increases in plasma steroids. Plasma progesterone and testosterone were increased sevenfold and plasma estradiol-17 beta fourfold by 10-24 hr postinjection. These studies demonstrate pregnancy stage-dependent differences in gonadal sensitivity to a pituitary ventral lobe gonadotropic moiety.
  • Authors

  • Tsang, Paul
  • Callard, IP
  • Status

    Publication Date

  • April 1988
  • Published In


  • Animals
  • Dogfish
  • Estradiol
  • Female
  • Kinetics
  • Pituitary Gland
  • Pregnancy
  • Progesterone
  • Sharks
  • Testosterone
  • Tissue Extracts
  • Digital Object Identifier (doi)

    Pubmed Id

  • 3371649
  • Start Page

  • 164
  • End Page

  • 168
  • Volume

  • 70
  • Issue

  • 1