2017新托福听力解析:多骨质少脂肪

　　Hi. I’m running. I’m also telling some of my stem cells what to do right now. Well, I probably am, based on a new study with mice.

　　We have what are called mesenchymal stem cells. This type of stem cell goes on to become either fat or bone. Researchers found out that endurance exercise triggers the stem cells to preferentially mature into bone. And having more bone cells means improved blood production, which means a higher oxygen carrying capacity, and better immune reaction and better wound clotting. The research appears in the Journal of the Federation of American Societies for Experimental Biology, commonly known as the FASEB Journal. [J. M. Baker, Michael De Lisio and Gianni Parise, "Endurance exercise training promotes medullary hematopoiesis"]

　　Researchers at McMaster University in Canada had mice work out on a treadmill for about an hour three times a week. A control group of mice watched Matlock reruns. Well, they may as well have. They did not work out. And the mice that exercised had way less fat in their bone marrow cavities, and a big increase in blood cells in the marrow and in the circulation. I don’t like exercising. But I really don’t like fat in my marrow.

　　—Steve Mirsky

　　一项对老鼠的研究发现，耐久力训练会影响间叶干细胞转化成骨质而非脂肪细胞，这使得运氧容量的增加和抵抗力的增强。Steve Mirsky报道。

　　嗨，我在跑步。顺便我也讲讲我的干细胞将要做些什么。呃，当然，这是基于最近一项对老鼠的实验所作的。

　　我们体内有所谓的间叶干细胞。这种干细胞要么成为脂肪细胞，要么成为骨质。研究者发现，耐久力训练会激发这些干细胞优先成熟为骨质。有更多的骨细胞意味着血液传输能力的提高，也就是更高的运氧容量以及更强的抵抗力和伤口愈合能力。这项研究发表在美国实验生物联合会(FASEB)的杂志上。[J.M. Baker, Michael De Lisio and Gianni Parise, Endurance exercise training promotes medullary hematopoiesis]

　　加拿大麦太大学的研究者让实验鼠一周三次地在踏车上训练。控制组的实验鼠看着Matlock重跑。呃，他们也是跑过的。不过他们没达到锻炼强度。那些经过锻炼的实验鼠在它们的骨髓腔里含有更少的脂肪，而且骨髓腔和循环内的血细胞数量都大幅提升。我不喜欢锻炼。不过我真的很讨厌骨髓里有脂肪。