想要健康? 像北極熊一樣睡覺
Hibernation is a complex solution to a simple problem. In winter, food is scarce. To survive this seasonal famine, animals, such as the arctic ground squirrel and black bear, induce a sedentary state under which physiological shifts keep them alive despite the lack of food, water and movement. Researchers and doctors alike are interested in how these hibernation tricks could help humans with their own health.
冬眠是簡單問題的複雜答案。冬天食物匱乏。北極地鼠和黑熊等動物爲了度過季節性饑荒，進入一種很少活動的狀態。在這種狀態下，生理變化讓它們在缺少食物、飲水和運動的情況下生存。冬眠能否幫助人類解決健康問題？科研人員和醫生都對此十分關注。
Stroke
中風
Blood flow in the brain of a hibernating arctic ground squirrel drops to a tenth of normal. Typically such oxygen deprivation would cause a stroke. But these squirrels can survive all winter because their metabolism lowers to 2 percent of its summer rate—requiring much less oxygen to maintain. If paramedics could similarly lower the metabolism of a human patient immediately after a stroke—perhaps by cooling the body—they might prevent permanent brain damage, says Brian Barnes, a biologist at the University of Alaska Fairbanks.
冬眠中的北極地鼠的腦部血液循環速度只有平時的十分之一。通常氧氣不足會導致中風，但北極地鼠在冬季的新陳代謝只有夏天的2%，這使得它們需要更少的氧氣就能存活。阿拉斯加費爾貝克斯大學的生物學家布萊恩·巴恩斯指出，如果醫護人員也能在病人中風後通過降低體溫等手段迅速降低人體的新陳代謝，就有可能避免永久性腦損傷。
Diabetes
糖尿病
People who gain a lot of weight often stop responding to insulin. The hormone regulates the amount of glucose that cells take up from the blood; too much sugar in the blood results in type 2 diabetes. Yet grizzly bears gain 100 pounds or more each autumn and somehow avoid diabetes. A recent study found that the grizzlies' fat cells become more sensitive to insulin as they prepare for the winter, allowing the bears to keep processing and storing sugar. Scientists at biotechnology company Amgen are now testing whether tweaking the same protein that controls sensitivity in diabetic humans could have similar results.
胰島素對肥胖人羣的效果往往不佳。荷爾蒙控制細胞從血液中吸收葡萄糖的數量，而血糖過高會導致2型糖尿病。然而每年秋天灰熊都會增加100磅以上的體重卻不會得糖尿病。一項近期研究發現，灰熊的脂肪細胞在準備越冬期間對胰島素更敏感，這使得灰熊能夠順利吸收和儲存糖分。人體內也有同樣的蛋白質可以調整對胰島素的敏感程度。安進公司的生物技術學家正在嘗試調整這種蛋白質是否會對糖尿病人產生類似的效果。
Osteoporosis
骨質疏鬆症
If a human were to lie still for long periods without food, his or her bones would slowly degrade. A black bear, however, emerges from its den after winter just as strong as ever because its bone is recycled at 25 percent of normal levels during hibernation. Researchers at Colorado State University are now trying to identify the hormones that control this extreme limit on bone turnover. They aim to create a drug for people at risk for osteoporosis that similarly protects bone density.
人如果不吃東西長期靜臥，骨骼就會退化。但春天從洞裏爬出來的黑熊卻和冬眠前一樣強壯。這是因爲在冬眠期間黑熊骨骼的流失率只有平時的25%。科羅拉多州立大學的科研人員正試圖找出是這種極度限制骨質流失的荷爾蒙。他們的目標是發明一種能讓骨質酥鬆症潛在患者保持骨骼密度的新藥。
Heart Disease
心臟病
During cardiac surgery, a patient becomes oxygen-deprived when the heart stops beating. To cope, the body switches from aerobic to anaerobic metabolism. Unfortunately, the change creates lactic acid, which can kill cells if it builds up. Damage of this kind does not occur in hibernating arctic ground squirrels, likely because they break down more fats than sugars even after the heart has slowed to just one beat per minute. Collaborating researchers at Duke University and the University of Alaska Fairbanks are now working to identify how this species prioritizes fat as fuel in low-oxygen conditions. Finding a way to coax cardiac surgery patients to do the same may reduce injury to organs during procedures.
心臟手術中，患者會因心臟停止跳動而缺氧。而人體會從有氧代謝轉變爲無氧代謝來應對。不幸的是，這種改變會產生乳酸。而乳酸一旦積累就會殺死細胞。冬眠的北極地鼠卻不會受到這種傷害。這可能是由於就算心跳下降到每分鐘一次，它們也會更多的分解脂肪而非糖。杜克大學和阿拉斯加費爾貝克斯大學的科研人員正一起致力於發現北極地鼠是如何在低氧環境下優先分解脂肪的。若是接受心臟手術的病人也能如此，就會減少手術中器官受到的損傷。
