Latency of oxygen toxicity of the central nervous system in rats as a function of carbon dioxide production and partial pressure of oxygen |
| |
Authors: | R Arieli |
| |
Institution: | (1) Israel Naval Medical Institute, PO Box 8040, Haifa 31080, Israel, IL |
| |
Abstract: | Oxygen toxicity of the central nervous system (CNS) can occur as convulsions and loss of consciousness, with no warning symptoms.
A quantitative study of the effect of metabolic rate on sensitivity to oxygen toxicity was made in the rat. A group of 19
rats were exposed (126 exposures) to 12 combinations of four pressures (456, 507, 608 and 709 kPa) and three ambient temperatures
(15, 23 and 29°C) until the appearance of the first electrical discharge (FED) preceding clinical convulsions. Carbon dioxide
production (V˙CO2) was also measured. A thermoneutral zone (mean V˙CO2 0.87 ml · g−1 · h−1) existed between the temperatures of 24 and 29°C; at temperatures lower than this, the metabolic rate increased by 1.2 to
4 times the resting level. Latency of FED decreased linearly with the increase in V˙CO2 at all four oxygen pressures. The slopes (absolute value) and intercepts decreased with the increase in oxygen pressure.
This linear relationship made possible the derivation of an equation which described latency of the FED as a function of both
oxygen pressure and metabolic rate. Various environmental and other physiological factors that have been said to influence
sensitivity to CNS oxygen toxicity, enhancing the effect of the partial pressure of oxygen, can be explained by their effect
on metabolic rate. It is suggested that in situations where there is a risk of oxygen toxicity of the CNS, that risk would
be reduced by a lower metabolic rate.
Accepted: 4 May 1998 |
| |
Keywords: | Hyperbaric oxygen Metabolic rate Electroencephalogram |
本文献已被 SpringerLink 等数据库收录! |
|