title: Steroid levels in tadpole (Rana catesbeiana) brain at the loss and return of the righting response.
abstract: Steroid levels were determined at the onset of anesthesia (tLRR) and at the recovery from anesthesia (tRRR). When 3 alpha-hydroxy-5 alpha-pregnan-20-one (3 alpha) was the administered agent, 3 alpha levels were similar at tLRR and tRRR1. The net rate of uptake of 3 alpha by the brain was approximately eight times the rate of loss of 3 alpha. Levels of 3 alpha were twice as high as tLRR when progesterone (PG) was the administered agent as when 3 alpha was used. The presence and absence of 0.1% ethanol in the incubation bath had no detectable effect on steroid levels. A model for the actions of 3 alpha is described. It is argued that interactions between 3 alpha and the target site are specific with respect to chemical structure and that the amount of 3 alpha in the compartment that contains the target sites is always small compared to that in whole brain.
authors.affiliation: Department of Anesthesia, Harvard Medical School, Brigham & Women's Hospital, Boston, MA 02115.
authors.forename: W M
authors.initials: WM
authors.lastname: Mok
authors.forename: N R
authors.initials: NR
authors.lastname: Krieger
mesh_terms: D000758:Anesthesia; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D007814:Larva; D004856:Postural Balance / Q000502:physiology*; D011280:Pregnanolone / Q000494:pharmacology; D011374:Progesterone / Q000494:pharmacology; D011892:Rana catesbeiana; D012018:Reflex / Q000502:physiology*; D013256:Steroids / Q000378:metabolism*
chemical_list: D013256:Steroids; D011374:Progesterone; D011280:Pregnanolone