来自《耶鲁大学开放课程：生物医学工程探索 第17集 第17集》

• 
  
  that it's neither reabsorbed or secreted,
  它既不被重吸收也不被排泌
• 
  
  and that's shown here by this flat line,
  通过这根平直线显示在这里
• 
  
  so whatever gets filtered in the glomerulus, at the glomerulus,
  因此不论多少分子渗入了肾小球
• 
  
  that number of molecules remains in the urine
  整个过程中通过肾小管内的分子数
• 
  
  throughout its progress through the tubules.
  全都留在尿液里
• 
  
  That's why you can use it as a tracer
  那就是它能作为示踪分子
• 
  
  to measure GFR (glomerular filtration rate )
  测量GFR[肾小球滤过率]的原因
• 
  
  because it's neither reabsorbed in any of these tubules nor secreted,
  因为它不会在任何肾小管中被排泌或被重吸收
• 
  
  so the number of molecules that come out in the filtrate,
  因此在滤液中所有的分子数量
• 
  
  that's the number that leave in the urine.
  也就是留在尿中的分子数量
• 
  
  That's not true for glucose.
  对于葡萄糖则非如此
• 
  
  I mentioned yesterday that glucose is not normally found in urine.
  我昨天说过葡萄糖在尿中一般是找不到的