Ascorbate dynamics and oxygen consumption during arousal from hibernation in Arctic ground squirrels.
Ascorbate dynamics and oxygen consumption during arousal from hibernation in Arctic ground squirrels.
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DOI：
10.1152/ajpregu.2001.281.2.r572
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发表时间：
2001-08
期刊：
影响因子：
--
通讯作者：
Ø. Tøien;K. Drew;M. L. Chao;M. Rice
中科院分区：
文献类型：
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作者：
Ø. Tøien;K. Drew;M. L. Chao;M. Rice
在冬眠期间，北极地松鼠（Spermophilus parryii）的O（2）消耗量和血浆白细胞计数减少了90%以上，而血浆中抗氧化剂抗坏血酸的浓度增加了四倍。在复温过程中，O（2）消耗显著增加，血浆抗坏血酸盐和白细胞计数恢复正常。在这里，我们研究了这些变化之间的动态相互关系。血浆抗坏血酸和尿酸（尿酸盐）浓度测定HPLC从血液样本收集在约15分钟的时间间隔通过动脉导管;白细胞计数和红细胞压积也进行了测定。连续记录体温、耗氧量和肌电活动。抗坏血酸，尿酸盐和谷胱甘肽含量在身体和大脑样品中测定在冬眠和觉醒后。在复温过程中，血浆抗坏血酸减少的最大速率发生在O（2）消耗峰值和血浆尿酸盐产生峰值的时间。抗坏血酸的减少与口腔或腹部温度无关;白细胞的摄取仅占一小部分。相比之下，肝脏和脾脏抗坏血酸水平显着增加唤醒后，这可以解释抗坏血酸从血浆中清除。脑抗坏血酸水平保持不变。这些数据表明，血浆中抗坏血酸[（Asc）]浓度升高[（Asc）（p）]提供了一种抗氧化剂来源，在伴随觉醒的代谢应激期间重新分布到组织中。
During hibernation in Arctic ground squirrels (Spermophilus parryii), O(2) consumption and plasma leukocyte counts decrease by >90%, whereas plasma concentrations of the antioxidant ascorbate increase fourfold. During rewarming, O(2) consumption increases profoundly and plasma ascorbate and leukocyte counts return to normal. Here we investigated the dynamic interrelationships among these changes. Plasma ascorbate and uric acid (urate) concentrations were determined by HPLC from blood samples collected at approximately 15-min intervals via arterial catheter; leukocyte count and hematocrit were also determined. Body temperature, O(2) consumption, and electromyographic activity were recorded continuously. Ascorbate, urate, and glutathione contents in body and brain samples were determined during hibernation and after arousal. During rewarming, the maximum rate of plasma ascorbate decrease occurred at the time of peak O(2) consumption and peak plasma urate production. The ascorbate decrease did not correlate with mouth or abdominal temperature; uptake into leukocytes could account for only a small percentage. By contrast, liver and spleen ascorbate levels increased significantly after arousal, which could more than account for ascorbate clearance from plasma. Brain ascorbate levels remained constant. These data suggest that elevated concentrations of ascorbate [(Asc)] in plasma [(Asc)(p)] provide an antioxidant source that is redistributed to tissues during the metabolic stress that accompanies arousal.