Effect of anesthesia on CBF, MAP and fMRI-BOLD signal in response to apnea.
Effect of anesthesia on CBF, MAP and fMRI-BOLD signal in response to apnea.
复制标题
麻醉对呼吸暂停反应中 CBF、MAP 和 fMRI-BOLD 信号的影响。
DOI：
10.1016/j.brainres.2004.02.076
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Biswal,BharatB
中科院分区：
文献类型：
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作者：
Kannurpatti,SridharS;Biswal,BharatB
麻醉对呼吸暂停诱导的血氧水平依赖（BOLD）信号动力学的全身影响尚不清楚。本研究采用激光多普勒血流仪（LDF）研究了呼吸暂停大鼠fMRI-BOLD信号和血流的动态变化。两种麻醉剂，戊巴比妥和聚氨酯，假设对平均动脉血压（MAP）有不同的影响。在正常的基线条件下，戊巴比妥麻醉的大鼠在呼吸暂停时MAP降低，但在氨基甲酸乙酯麻醉下MAP升高。然而，在两种麻醉药的高氧或高碳酸血症基线条件下，MAP对呼吸暂停的反应没有显著变化。在常氧、高氧或高碳酸血症时，LDF对呼吸暂停的反应增加，并受MAP的影响。呼吸暂停诱导的BOLD信号动力学与两种麻醉剂相似，主要受动脉血氧变化的影响，与MAP的变化无关。我们的研究结果表明，麻醉依赖性MAP改变调节了呼吸暂停诱导的脑血流（CBF）反应，但对fMRI-BOLD信号的影响很小，这可能是由于CBF和氧气消耗的解耦。
Systemic effects of anesthesia on the dynamics of the apnea-induced Blood Oxygen Level Dependent (BOLD) signal is still not clear. In the present study, the dynamics of the fMRI-BOLD signal and blood flow using laser Doppler flowmetry (LDF) was studied in rats in response to apnea. Two anesthetics namely pentobarbital and urethane, hypothesized to have distinct effects on the mean arterial blood pressure (MAP) were used. During normoxic baseline conditions, MAP decreased in response to apnea in rats anesthetized with pentobarbital but increased with urethane. However, MAP did not change significantly in response to apnea during hyperoxic or hypercapnic baseline conditions with both anesthetics. LDF increased in response to apnea during normoxia, hyperoxia or hypercapnia and was influenced by MAP during normoxia. Apnea-induced BOLD signal dynamics was similar with both anesthetics, dominated by an alteration in arterial blood oxygenation and independent of changes in MAP. Our results suggest that anesthesia-dependent MAP change modulates the apnea-induced cerebral blood flow (CBF) response but has a minimal effect on the fMRI-BOLD signal probably due to uncoupling of CBF and oxygen consumption.