rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    non sort: The
    title: effects of simulated microgravity on the regulation of cerebral perfusion
  name:
    name part: Wilkerson, Michael Keith.
    role:
      role term: creator
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: xx
    date issued: 2002
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: viii, 64 leaves : illustrations ; 28 cm.
  abstract: The purpose of these studies was to test the hypothesis that cephalic fluid shifts induced by head-down tail-suspension (HDT) in the rat lead to alterations in cerebrovascular regulation of brain blood flow. Histological cross-sections made of basilar artery from control and 14-day HDT animals revealed that media cross-sectional area (CSA) and thickness were increased with HDT, intraluminal CSA decreased, and vessel outer perimeter and media nuclei number were unaltered. To determine whether these changes in morphology are due to mechanical factors, cerebral blood flow and vascular resistance and arterial pressure were measured in control rats during normal standing and following 10 min of HDT, and in two groups of rats following 7- and 28-day HDT. Mean arterial pressure was elevated at 10 min HDT relative to the other conditions. Total brain blood flow was reduced and total vascular resistance was greater following 10 min, 7- and 28-day HDT, respectively, relative to that during control standing. These findings suggest that HDT leads to enhanced cerebral vasoconstrictor responsiveness. To determine the mechanism and functional significance of a putative change in vasoconstrictor responsiveness, additional studies were performed on control and 14-day HDT rats. First, dose responses to pressure, luminal flow, potassium, and vasodilatory agents were determined in isolated middle cerebral arteries. These studies were performed with and without nitric oxide (NO) synthase blockade. In most cases, NO blockade attenuated response differences between groups. This demonstrates that basal release of nitric oxide is diminished by HDT, and this appears to account for enhanced myogenic, shear stress-induced and agonist-induced constriction. In the second study, blood pressure and blood flow to brain regions were determined during either normal standing and head-up tilt in both groups of rats. During head-up tilt, the HDT rats became hypotensive, yet cerebral vascular resistance …
  note: by Michael Keith Wilkerson.
  note: Vita.
  note: "Major Subject: Kinesiology".
  note: Issued also on microfiche from University Microfilm Inc.
  note: Ph. D. Texas A&M University 2002.
  note: Includes bibliographical references (leaves 52-63).
  subject:
    topic: Major kinesiology
  identifier: 30-60927 UMI
  identifier: http://proxy.library.tamu.edu/login
  related item:
    location:
      url: http://proxy.library.tamu.edu/login
  record info:
    record content source: TXA
    record creation date: 030414
    record change date: 20190325103159.0
    record identifier: in00001735883