Since proteins should not be present in urine, how can the human chorionic gonadotropin (hCG) be present in urine during pregnancy? Does it pass through the filter in Bowman's capsule?

1 Answer
May 16, 2018

Yes, it passes through the filter in Bowman's capsule.

Explanation:

Glomerular filtration stops large proteins getting through into the urine. However, small proteins (roughly 30 kDa) can pass through the membrane with no problems. hCG is approximately 37 kDa. So although it can't pass through easily, it still can pass through the membrane and get into urine.