Journal of Applied Physiology Information on EB 2010
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 58: 1988-1996, 1985;
8750-7587/85 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Saetta, M.
Right arrow Articles by Mortola, J. P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Saetta, M.
Right arrow Articles by Mortola, J. P.

Journal of Applied Physiology, Vol 58, Issue 6 1988-1996, Copyright © 1985 by American Physiological Society

ARTICLES

Breathing pattern and CO2 response in newborn rats before and during anesthesia

M. Saetta and J. P. Mortola

We have studied the breathing pattern (minute ventilation VE, tidal volume VT, and respiratory rate f) in newborn rats before and during barbiturate (20-30 mg/kg ip) or ketamine anesthesia (40-80 mg/kg ip). Animals were intact and prone in a flow plethysmograph in thermoneutral conditions. Before anesthesia, CO2 breathing (5 min in 5% and 5 min in 10% CO2 in O2) resulted in a substantial increase in VE (169 and 208%, respectively), which was maintained throughout the entire CO2 breathing period. This indicates that, despite the extremely large VE per kilogram at rest, in these small animals there is still a large reserve for a sustained increase in VE. During barbiturate, the resting VE dropped to 45% of control, due to a reduction in VT (83%) and f (59%). This latter result was due to a prolongation of the expiratory time (214%) with no significant changes in inspiratory time. CO2 response was also much depressed, to approximately 63% of the control. The late portion of the expiratory flow-volume curves, the slope of which represents the expiratory time constant of the system, was similar before and during anesthesia in approximately 50% of the animals, whereas it increased during anesthesia in the remaining animals. Although compliance of the respiratory system was generally unaltered, the increased impedance during anesthesia probably reflected an increased resistance. Qualitatively similar results were obtained during ketamine anesthesia. Therefore, as observed in adult mammals, anesthesia in newborn rats has a marked depressant effect on resting breathing pattern and CO2 response, occasionally accompanied by an increase in the expiratory impedance of the respiratory system.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
P. Tourneux, N. Markham, G. Seedorf, V. Balasubramaniam, and S. H. Abman
Inhaled nitric oxide improves lung structure and pulmonary hypertension in a model of bleomycin-induced bronchopulmonary dysplasia in neonatal rats
Am J Physiol Lung Cell Mol Physiol, December 1, 2009; 297(6): L1103 - L1111.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
R. Wang and F. Xu
Postnatal development of right atrial injection of capsaicin-induced apneic response in rats
J Appl Physiol, July 1, 2006; 101(1): 60 - 67.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online