Date of Award
Spring 1987
Document Type
Thesis - Restricted
Degree Name
Master of Science (MS)
Department
Dentistry
First Advisor
Quock, Raymond M.
Second Advisor
Pruhs, Ron
Third Advisor
Post, Chuck
Abstract
Nitrous oxide has been demonstrated to produce varied cardiovascular effects including sympathetic nervous activation and peripheral vasoconstriction (Trieger et al., 1971; Everett and Allen, 1971) and has not been frequently used in cardiovascularly compromised dental patients. More recent studies, though, have shown that the hemodynamic effects of nitrous oxide in cardiac patients are negligible and possibly even beneficial (Dottori and Korsgren, 1976; Sumners, 1981). The present study was conducted to determine cardiovascular effects of nitrous oxide inhalation in normotensive Wistar-Kyoto rats and Spontaneously hypertensive rats. Mean systolic blood pressure and heart rate were determined by plethysmography in 12-20 week old, male normotensive and hypertensive animals. The animals were restrained in Plexiglas cylinders through which flowed 20%, 40% or 60% nitrous oxide or nitrogen in oxygen. Changes in systolic blood pressure and heart rate were determined at five minute intervals before, during and after a thirty minute exposure of nitrous oxide or nitrogen. The results were analyzed by analysis of variance and Duncan's multiple range test. Significant cardiovascular effects produced by nitrous oxide were determined by 1) comparison of each animal group to its pre-exposure baseline value, as its own control, and by 2) comparison of each experimental group to its respective control group response. The results indicate that nitrous oxide produces a concentration related reduction in both systolic blood pressure and heart rate. The heart rate seems to be more sensitive to alteration by nitrous oxide than the blood pressure. In addition, the hypertensive animals would seem to benefit more from the cardiovascular effects of nitrous oxide. The hypertensive animals are more sensitive to nitrous oxide's blood pressure and heart rate effects as compared to their normotensive counterparts. These findings indicate that nitrous oxide lowers systolic blood pressure and heart rate in both normotensive and hypertensive rats and that exposure to nitrous oxide does not exacerbate a hypertensive condition.
Recommended Citation
Henry, Robert J., "Cardiovascular Influences of Nitrous Oxide in Hypertensive and Normotensive Rats" (1987). Master's Theses (1922-2009) Access restricted to Marquette Campus. 5338.
https://epublications.marquette.edu/theses/5338