[citation needed] Countercurrent multiplication was originally studied as a mechanism whereby urine is concentrated in the nephron.
Initially studied in the 1950s by Gottschalk and Mylle following Werner Kuhn's postulations,[3] this mechanism gained popularity only after a series of complicated micropuncture experiments.
In a hypothetical model where there was no equilibration or pump steps, the tubular fluid and interstitial osmolarity would be 300 mOsm/L as well.
{Respicius Rwehumbiza, 2010} Pump: The Na+/K+/2Cl− transporter in the ascending limb of the loop of Henle helps to create a gradient by shifting Na+ into the medullary interstitium.
The thick ascending limb of the loop of Henle is the only part of the nephron lacking in aquaporin—a common transporter protein for water channels.