dc.contributor.author |
Galinsky, Robert |
en |
dc.contributor.author |
Lear, Christopher |
en |
dc.contributor.author |
Yamaguchi, K |
en |
dc.contributor.author |
Wassink, Guido |
en |
dc.contributor.author |
Westgate, JA |
en |
dc.contributor.author |
Bennet, Laura |
en |
dc.contributor.author |
Gunn, Alistair |
en |
dc.date.accessioned |
2017-03-06T02:34:09Z |
en |
dc.date.issued |
2016-11-01 |
en |
dc.identifier.citation |
American Journal of Physiology - Regulatory Integrative and Comparative Physiology 311(5):R949-R956 01 Nov 2016 |
en |
dc.identifier.issn |
0363-6119 |
en |
dc.identifier.uri |
http://hdl.handle.net/2292/32060 |
en |
dc.description.abstract |
The role of cholinergic and β-adrenergic activity in mediating fetal cardiovascular recovery from brief repeated episodes of asphyxia consistent with established labor, remains unclear. In this study, we tested the effect of cholinergic and β-adrenergic blockade on the fetal chemoreflex and fetal heart rate (FHR) overshoot responses during brief repeated asphyxia at rates consistent with early or active labor. Chronically instrumented fetal sheep at 0.85 of gestation received either i.v. atropine sulfate (cholinergic blockade, n=8) or vehicle (n=7) followed by 3 x 1-minute umbilical cord occlusions repeated every 5 minutes (1:5; consistent with early labor), or i.v. propranolol hydrochloride (β-adrenergic blockade, n=6) or vehicle (n=6) followed by 3 x 2-minute occlusions repeated every 5 minutes (2:5; consistent with active labor). In vehicle-controls, 1:5 occlusions were associated with rapid and sustained FHR decelerations followed by rapid return of FHR to baseline values after release of the occlusion. Cholinergic blockade abolished FHR decelerations during occlusions and caused FHR overshoot after release of the occlusion (P<0.05 vs. control 1:5). In vehicle-controls, 2:5 occlusions caused rapid and sustained FHR decelerations followed by FHR overshoot after release of the occlusion. β-adrenergic blockade was associated with greater reduction in FHR during occlusions and attenuated FHR overshoot (P<0.05 vs. control 2:5). These data demonstrate that the FHR overshoot pattern after asphyxia is mediated by a combination of attenuated parasympathetic activity and increased β-adrenergic stimulation of the fetal heart. |
en |
dc.language |
ENG |
en |
dc.publisher |
American Physiological Society |
en |
dc.relation.ispartofseries |
American Journal of Physiology - Regulatory Integrative and Comparative Physiology |
en |
dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. Details obtained from http://www.sherpa.ac.uk/romeo/issn/0363-6119/ |
en |
dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
en |
dc.subject |
Chemoreflex |
en |
dc.subject |
Fetal Sheep |
en |
dc.subject |
Fetal asphyxia |
en |
dc.subject |
autonomic nervous system |
en |
dc.title |
Cholinergic and β-adrenergic control of cardiovascular reflex responses to brief repeated asphyxia in term-equivalent fetal sheep |
en |
dc.type |
Journal Article |
en |
dc.identifier.doi |
10.1152/ajpregu.00340.2016 |
en |
pubs.issue |
5 |
en |
pubs.begin-page |
R949 |
en |
pubs.volume |
311 |
en |
dc.description.version |
AM - Accepted Manuscript |
en |
dc.rights.holder |
Copyright: American Physiological Society |
en |
dc.identifier.pmid |
27654399 |
en |
pubs.end-page |
R956 |
en |
pubs.publication-status |
Published online |
en |
dc.rights.accessrights |
http://purl.org/eprint/accessRights/OpenAccess |
en |
pubs.subtype |
Article |
en |
pubs.elements-id |
541744 |
en |
pubs.org-id |
Medical and Health Sciences |
en |
pubs.org-id |
Medical Sciences |
en |
pubs.org-id |
Physiology Division |
en |
dc.identifier.eissn |
1522-1490 |
en |
dc.identifier.pii |
ajpregu.00340.2016 |
en |
pubs.record-created-at-source-date |
2016-09-27 |
en |
pubs.online-publication-date |
2016-09-21 |
en |
pubs.dimensions-id |
27654399 |
en |