TY - JOUR
T1 - Effects of dexmedetomidine on microregional O2 balance during reperfusion after focal cerebral ischemia
AU - Chi, Oak Z.
AU - Grayson, Jeremy
AU - Barsoum, Sylviana
AU - Liu, Xia
AU - Dinani, Aliraza
AU - Weiss, Harvey
N1 - Publisher Copyright:
© 2015 National Stroke Association.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - Background This study was performed to determine whether there is an association between microregional O2 balance and neuronal survival in cerebral ischemia-reperfusion using dexmedetomidine, an α2-Adrenoreceptor agonist and a sedative. Methods Rats were subjected to 1 hour middle cerebral artery occlusion and a 2-hour reperfusion. During reperfusion, normal saline (n = 14) or dexmedetomidine 1 μg/kg/minute (n = 14) was infused intravenously. At 2 hours of reperfusion, regional cerebral blood flow using 14C-iodoantipyrine autoradiography, microregional arterial and venous (20-60 μm in diameter) O2 saturation (SvO2) using cryomicrospectrophotometry, and the size of cortical infarction were determined. Results Ischemia-reperfusion decreased microregional SvO2 (52.9 ± 3.7% vs. 61.1 ±.6%, P <.005) with increased variation or heterogeneity (P <.0001) with similar regional cerebral blood flow and O2 consumption. Dexmedetomidine during reperfusion decreased the heterogeneity of SvO2 that was analyzed with an analysis of variance (P <.01) and reported as coefficient of variation (100 × standard deviation/Mean) (11.8 vs. 16.4). The number of veins with O2 saturation less than 50% decreased with dexmedetomidine (13/80 vs. 27/81, P <.01). The percentage of cortical infarct in total cortex was smaller with dexmedetomidine (8.3 ± 2.2% vs. 12.6 ± 1.5%, P <.005). Conclusions In the cerebral ischemic reperfused cortex, dexmedetomidine decreased the heterogeneity of SvO2 and the number of small veins with low O2 saturation suggesting improved microregional O2 supply/consumption balance. The improvement was accompanied by the reduced size of cortical infarction.
AB - Background This study was performed to determine whether there is an association between microregional O2 balance and neuronal survival in cerebral ischemia-reperfusion using dexmedetomidine, an α2-Adrenoreceptor agonist and a sedative. Methods Rats were subjected to 1 hour middle cerebral artery occlusion and a 2-hour reperfusion. During reperfusion, normal saline (n = 14) or dexmedetomidine 1 μg/kg/minute (n = 14) was infused intravenously. At 2 hours of reperfusion, regional cerebral blood flow using 14C-iodoantipyrine autoradiography, microregional arterial and venous (20-60 μm in diameter) O2 saturation (SvO2) using cryomicrospectrophotometry, and the size of cortical infarction were determined. Results Ischemia-reperfusion decreased microregional SvO2 (52.9 ± 3.7% vs. 61.1 ±.6%, P <.005) with increased variation or heterogeneity (P <.0001) with similar regional cerebral blood flow and O2 consumption. Dexmedetomidine during reperfusion decreased the heterogeneity of SvO2 that was analyzed with an analysis of variance (P <.01) and reported as coefficient of variation (100 × standard deviation/Mean) (11.8 vs. 16.4). The number of veins with O2 saturation less than 50% decreased with dexmedetomidine (13/80 vs. 27/81, P <.01). The percentage of cortical infarct in total cortex was smaller with dexmedetomidine (8.3 ± 2.2% vs. 12.6 ± 1.5%, P <.005). Conclusions In the cerebral ischemic reperfused cortex, dexmedetomidine decreased the heterogeneity of SvO2 and the number of small veins with low O2 saturation suggesting improved microregional O2 supply/consumption balance. The improvement was accompanied by the reduced size of cortical infarction.
KW - Cerebral ischemia reperfusion
KW - cerebral O supply and consumption balance
KW - cerebral venous O saturation
KW - α agonist
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U2 - 10.1016/j.jstrokecerebrovasdis.2014.08.004
DO - 10.1016/j.jstrokecerebrovasdis.2014.08.004
M3 - Article
C2 - 25294058
AN - SCOPUS:84920720169
SN - 1052-3057
VL - 24
SP - 163
EP - 170
JO - Journal of Stroke and Cerebrovascular Diseases
JF - Journal of Stroke and Cerebrovascular Diseases
IS - 1
ER -