Hippocrates' Intuition on the Renal Tubule's Role in Ion Exchange

Objectives: The goal of this article was to trace any similarity between the current knowledge on the physiology of the afferent, efferent convoluted tubules, the Loop of Henle, and a passage of Hippocrates' work "Regimen." Materials and Methods: We compared the function of the renal tubule with the Regimen (1.6) passage on the similarity between the sawing of a tree and the body's function. Results: The renal tubule, from its beginning to its end, pushes electrolytes, micronutrients, and water out of its interior into the interstitial space and, following the opposite procedure, reabsorbs some of them, eventually achieving internal equilibrium. The Regimen passage elaborated as follows: "All other things are set in due order [...] Those that take give increase, those that give make diminution. Men saw a log; the one pulls and the other pushes, but herein they do the same thing, and while making less they make more. Such is the nature of man. One part pushes, the other pulls; one part gives, the other takes." Conclusions: Hippocrates did not, and could not, know the details of renal function. Although his hypothesis is crude, we are justified to consider it as the medical ancestor of our current physiological knowledge about the role of the renal tubules.