Cerebral blood flow and metabolism in soman-induced convulsions.
Regional cerebral blood flow (CBF) and regional cerebral glucose utilization (CGU) were studied by quantitative autoradiographic techniques in rats. Animals were treated either with a toxic dose of soman, an irreversible organophosphorus cholinesterase inhibitor, that produced convulsions or with saline as controls. An increased arterial blood pressure (mean increase = 41% of control) always preceded onset of convulsions. Convulsive activity was associated with an increase of plasma glucose concentration and marked increases over controls of CGU [average of all regions: control = 75 +/- 5 mumol.100 g-1.min-1, n = regions/animals (304/8); seizures = 451 +/- 20 mumol.100 g-1.min-1, n = 190/5] and CBF [average of all regions: control = 135 +/- 6 ml.100 g-1.min-1, n = 190/5; seizures = 619 +/- 29 ml.100 g-1.min-1, n = 190/5). Regional distribution of these effects revealed a greater proportional increase of CBF over CGU in cingulate, motor, and occipital cortex and caudate-putamen. In contrast, a lower proportional increase of CBF over CGU in CA3 region of hippocampus, dentate gyrus, medial thalamus, and substantia nigra was observed, implying the existence of a relative ischemia in these brain areas. These findings may be relevant to the pathogenesis of brain lesions associated with soman-induced convulsions.
Shih
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TM
U.S. Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010.
Scremin
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OU
D000818:Animals; D000983:Antipyrine / Q000031:analogs & derivatives; D001345:Autoradiography; D001522:Behavior, Animal / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D001923:Brain Chemistry / Q000187:drug effects*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D005947:Glucose / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012640:Seizures / Q000139:chemically induced / Q000378:metabolism*; D012999:Soman / Q000633:toxicity*
D012999:Soman; D005947:Glucose; D000983:Antipyrine; C008135:iodoantipyrine