title: In vivo steroidogenic effects of homologous pituitary ventral lobe extract in the spiny dogfish, Squalus acanthias.
abstract: 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 Blood samples were withdrawn by caudal sinus puncture at intervals over a period of 72 hr and plasma progesterone, testosterone, and estradiol-17 beta measured by radioimmunoassay.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: Department of Biology, Boston University, Massachusetts 02215.
authors: P C
authors: PC
authors: Tsang
authors: I P
authors: IP
authors: Callard
mesh_terms: D000818:Animals; D004284:Dogfish / Q000502:physiology*; D004958:Estradiol / Q000097:blood*; D005260:Female; D007700:Kinetics; D010902:Pituitary Gland / Q000502:physiology*; D011247:Pregnancy; D011374:Progesterone / Q000097:blood*; D012754:Sharks / Q000502:physiology*; D013739:Testosterone / Q000097:blood*; D014020:Tissue Extracts / Q000494:pharmacology*
chemical_list: D014020:Tissue Extracts; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol