TY - JOUR T1 - DIGITAL COMPUTER SIMULATION OF THE NEPHRON: THE ACTION OF OSMOTIC DIURETICS JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 198 LP - 209 VL - 163 IS - 1 AU - GERALD A. KIEN AU - ESMAIL KOUSHANPOUR Y1 - 1968/09/01 UR - http://jpet.aspetjournals.org/content/163/1/198.abstract N2 - A simulation model of nephron function was developed in which the loop of Henle acts as the countercurrent multiplier and an active time-limited sodium transport system along the ascending limb of the loop of Henle initiates the "single effect." The vasa recta acts passively as a countercurrent exchanger. Urea gradients are developed in the model through a passive time-dependent redistribution process which operates as a function of the regional osmotic redistribution of water. The steady-state antidiuretic operation of the model results in the development of renal interstitial osmotic profiles and in tubular filtrate-to-plasma ratios of inulin, electrolytes and urea that correspond closely with experimental data. Perturbations of the simulation model corresponding to some proposed mechanisms of saline-and mannitol-induced diuresis also result in a close correspondence between the model and experimental data, allowing further evaluation of these proposed mechanisms. © 1968, by The Williams & Wilkins Company ER -