TY - JOUR
T1 - Seizure-associated pulmonary edema and cerebral oxygenation in the rat
AU - Kreisman, N. R.
AU - Hodin, R. A.
AU - Brizzee, B. L.
AU - Rosenthal, M.
AU - Sick, T. J.
AU - Busto, R.
AU - Ginsberg, M. D.
PY - 1987
Y1 - 1987
N2 - Cerebral partial pressure of O2 (PO2), relative changes in the ratio of reduced/oxidized cytochrome aa3, blood flow, and the arteriovenous difference in O2 content were measured during seizures with and without pulmonary edema. Seizures were induced with bicuculline (0.2-1.2 mg/kg iv) in rats anesthetized with 70% N2O and paralyzed with curare. Briefer seizures were accompanied by increased cerebral PO2 and increased oxidation of cytochrome aa3. Lung water content and arterial O2 partial pressure (Pa(O2)) remained normal. Longer duration seizures were also accompanied initially by increases in cerebral oxygenation. Within minutes, however, Pa(O2) fell from a mean of 118 to 51 mmHg, and lung water content increased from 76.2 to 83.6%. Cerebral PO2 fell but most often rose back to or above control levels, while cytochrome aa3 became markedly reduced. Simultaneously, cerebral blood flow increased more than 300% above preseizure values and O2 delivery increased more than O2 consumption. The reductive shift of cytochrome aa3 was greater than that produced by lowering Pa(O2) to equivalent values in seizures-free rats. The reductive shift of cytochrome aa3, despite increased O2 delivery, may be indicative of derangements in cerebral O2 diffusion or energy metabolism.
AB - Cerebral partial pressure of O2 (PO2), relative changes in the ratio of reduced/oxidized cytochrome aa3, blood flow, and the arteriovenous difference in O2 content were measured during seizures with and without pulmonary edema. Seizures were induced with bicuculline (0.2-1.2 mg/kg iv) in rats anesthetized with 70% N2O and paralyzed with curare. Briefer seizures were accompanied by increased cerebral PO2 and increased oxidation of cytochrome aa3. Lung water content and arterial O2 partial pressure (Pa(O2)) remained normal. Longer duration seizures were also accompanied initially by increases in cerebral oxygenation. Within minutes, however, Pa(O2) fell from a mean of 118 to 51 mmHg, and lung water content increased from 76.2 to 83.6%. Cerebral PO2 fell but most often rose back to or above control levels, while cytochrome aa3 became markedly reduced. Simultaneously, cerebral blood flow increased more than 300% above preseizure values and O2 delivery increased more than O2 consumption. The reductive shift of cytochrome aa3 was greater than that produced by lowering Pa(O2) to equivalent values in seizures-free rats. The reductive shift of cytochrome aa3, despite increased O2 delivery, may be indicative of derangements in cerebral O2 diffusion or energy metabolism.
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U2 - 10.1152/jappl.1987.62.2.658
DO - 10.1152/jappl.1987.62.2.658
M3 - Article
C2 - 3558225
AN - SCOPUS:0023218116
VL - 62
SP - 658
EP - 667
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 2
ER -