Distribution of Henle's loops may enhance urine concentrating capability.
A simple mathematical model that was developed by Charles S. Peskin (unpublished manuscript) for a single nephron is introduced and then extended to reflect the decreasing loop of Henle population as a function of increasing medullary depth. In the model, if all the loops turn at the same depth, the concentrating capability is limited by a factor of e over plasma osmolality. However, a decreasing loop population causes a multiplier effect that greatly enhances the concentrating capability. Using the loop distribution of the rat, the model produces a sigmoidal osmolality profile similar to the profiles found in tissue-slice studies of rat kidneys. These model calculations suggest that the decreasing nephron population found in vivo may be an important factor in the concentrating mechanism of the mammalian kidney.
Layton
H E
HE
D000818:Animals; D007684:Kidney Tubules / Q000502:physiology*; D007700:Kinetics; D008138:Loop of Henle / Q000502:physiology*; D008433:Mathematics; D008954:Models, Biological; D009399:Nephrons / Q000502:physiology*; D012079:Renal Circulation; D014556:Urine