A man with diabetes insipidus has a glomerular filtration of 155 L/day. Which range most likely represents the upper limit for urine flow rate in this individual if he were not receiving treatment but had free access to water?

Ans. C. 15 to 20 L/dayUrine flow rate in the absence of antidiuretic hormone (ADH) can approach approximately 10% to 13% of the glomerular filtration therefore, for a glomerular filtration of 155 L/day, urine flow could be as much as 15 to 20 L/ day. To maintain this level of urine flow, the individual must consume an equivalent amount of water per day.