Sex differences of human cortical blood flow and energy metabolism
Sex differences of human cortical blood flow and energy metabolism
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DOI：
10.1177/0271678x16668536
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发表时间：
2017-07-01
影响因子：
6.3
通讯作者：
Gjedde, Albert
中科院分区：
文献类型：
--
作者：
Aanerud, Joel;Borghammer, Per;Gjedde, Albert
大脑能量代谢被认为反映了神经纤维中与突触密度和活动相关的能量需求过程。最近有证据表明，男性颞叶皮层的突触密度高于女性。这些差异的后果之一就是男性和女性的皮质能量周转率和血流量不同。为了验证男性大脑皮层区域的耗氧率 (CMRO2) 和脑血流量高于女性的假设，以及这种差异随着年龄的增长而持续存在，我们使用正电子发射断层扫描来确定健康男女志愿者的脑血流量和脑氧代谢率作为年龄的函数。男女脑氧代谢率均不随年龄而变化，男女大脑皮层脑氧代谢率平均值无差异。随着年龄的增长，女性额叶和顶叶的脑血流量显着减少。年轻女性的额叶和颞叶脑血流量明显高于男性，但这些差异在 65 岁时就消失了。脑能量周转率不存在性别差异，这表明已知的两性突触密度差异被个体突触活动的相反差异所抵消。
Brain energy metabolism is held to reflect energy demanding processes in neuropil related to the density and activity of synapses. There is recent evidence that men have higher density of synapses in temporal cortex than women. One consequence of these differences would be different rates of cortical energy turnover and blood flow in men and women. To test the hypotheses that rates of oxygen consumption (CMRO2) and cerebral blood flow are higher in men than in women in regions of cerebral cortex, and that the differences persist with aging, we used positron emission tomography to determine cerebral blood flow and cerebral metabolic rate of oxygen as functions of age in healthy volunteers of both sexes. Cerebral metabolic rate of oxygen did not change with age for either sex and there were no differences of mean values of cerebral metabolic rate of oxygen between men and women in cerebral cortex. Women had significant decreases of cerebral blood flow as function of age in frontal and parietal lobes. Young women had significantly higher cerebral blood flow than men in frontal and temporal lobes, but these differences had disappeared at age 65. The absent sex difference of cerebral energy turnover suggests that the known differences of synaptic density between the sexes are counteracted by opposite differences of individual synaptic activity.