Simulation of lithium transport along the thin segments of Henle's loop

Taniguchi, Junichi; Shirley, David G.; Walter, Stephen J.; Imai, Masashi
August 1993
Kidney International;Aug1993, Vol. 44 Issue 2, p337
Academic Journal
Although the renal clearance of lithium is widely used as an index of sodium and water delivery to the end of the proximal tubule, micropuncture studies of superficial nephrons suggest that lithium may be reabsorbed additionally in the loop of Henle. In order to examine the possibility of lithium transport in the thin loop segments of deep nephrons, we conducted a computer simulation study using a modification of the mathematical model reported previously [1]. The data for the model were obtained from measurements of osmolality and electrolyte concentrations in systemic plasma and renal papillary interstitial fluid of control and furosemide-treated rats. Papillary interstitium/plasma Li+ concentration ratios were 3.23 and 1.48 in the control and the furosemide group, respectively. Assuming that solute concentration in the renal medulla increases as an exponential function, and applying phenomenological coefficients obtained from hamsters, the transport profiles of Li+ along the thin loop segments were calculated to be very similar to those of Na+. In the control group, about 82% of delivered Li+ was reabsorbed along the entire thin loop segments, with all segments contributing equally. This value may represent the highest possible capacity of the thin loop segments. In the furosemide group, Li+ reabsorption in the thin loop was reduced to 31% of delivered Li+. From these analyses, we conclude that an appreciable amount of lithium may be reabsorbed in the thin loop segments of long-looped nephrons by passive mechanisms. Furosemide inhibits Li+ reabsorption by dissipating the osmotic concentration gradient in the renal medulla. The-findings suggest that results from lithium clearance may underestimate end-proximal fluid delivery in deep nephrons and that lithium clearance studies should therefore be interpreted with caution, particularly in situations where the medullary osmotic gradient is likely to be disturbed.


Related Articles

  • Lithium and the kidney. Singer, Irwin // Kidney International;Feb1981, Vol. 19 Issue 2, p374 

    Discusses the important renal and electrolyte abnormalities associated with the use of lithium in clinical practice. Details on the standard dose of lithium carbonate for a psychiatric disturbance; Symptoms of lithium toxicity; Examination of several functional renal tubular defects associated...

  • Lithium Carbonate - a Competitive Aldosterone Antagonist? Stewart, Paul M.; Atherden, Sheila M.; Stewart, Susan E.; Whalley, Lawrence; Edwards, Christopher R. W.; Padfield, Paul L. // British Journal of Psychiatry;Aug88, Vol. 153, p205 

    Plasma renin activity (PRA), aldosterone (aldo) levels, electrolyte levels, and blood pressures were measured in 16 patients with affective disorders taking lithium prophylactically, and in 16 age and sex-matched control subjects. PRA and aldo levels were significantly elevated in the...

  • TGF-Mediated Dynamics in a System of Many Coupled Nephrons. Bayram, Saziye; Stepien, Tracy L.; Pitman, E. Bruce // Bulletin of Mathematical Biology;Aug2009, Vol. 71 Issue 6, p1482 

    This paper presents a mathematical model of a system of many coupled nephrons branching from a common cortical radial artery, and accompanying analysis of that system. This modeling effort is a first step in understanding how coupling magnifies the tendency of nephrons to oscillate owing to...

  • A Shunt Model of the Inner Medullary Nephron with Pre-Bend Transitions. Gonzalez, M. T.; Hegarty, A. F.; Thomas, S. R. // AIP Conference Proceedings;9/9/2009, Vol. 1168 Issue 1, p1469 

    Mathematical models of the renal medulla face the problem of representing water and solute transfer among tens of thousands of nephrons and blood vessels of various lengths, arranged in countercurrent fashion. Published models fall into two broad categories with respect to this issue:...

  • Extracellular Mg[sup2+]- and ca[sup2+]-sensing in mouse distal convoluted tubule cells. Bapty, Brian W.; Long-Jun Dai; Ritche, Gordon; Jirik, Frank; Canaff, Lucie; Hendy, Geoffrey N.; Quamme, Gary A. // Kidney International;Mar1998, Vol. 53 Issue 3, p583 

    Focuses on the effects of magnesium and calcium sensing in mouse distal convoluted tubule cells. Cellular mechanism of electrolyte transport within the mouse distal convoluted tubule; Implication of the magnesium and calcium sensing in the mouse distal convoluted tubule cells; Role of MDCT...

  • Analysis of nanoliter samples of electrolytes using a flow-through microfluorometer. Zhelyaskov, Valentin R.; Liu, Suyi; Broderick, Mark P.; Zhelyaskov, V R; Liu, S; Broderick, M P // Kidney International;Apr2000, Vol. 57 Issue 4, p1764 

    Several techniques have been developed to study the transport properties of nanoliter samples of renal tubule segments, such as continuous flow colorimetry and continuous fluorometry. We have extended the capability of the NANOFLO, a flow-through microfluorometer, designed for measurement of...

  • Improved Model Predictive Control for a Proton Exchange Membrane Fuel Cell. Liping Fan; Jun Zhang; Yi Liu; Xiaolin Shi // International Journal of Electrochemical Science;Sep2012, Vol. 7 Issue 9, p8734 

    Proton exchange membrane fuel cells are promising energy sources. Because of their time-change, uncertainty, strong-coupling and nonlinear characteristics, proton exchange membrane fuel cells present complex control challenges. Based on mathematical modelling and numerical simulations, two...

  • Adaptive, multi-parameter battery state estimator with optimized time-weighting factors. Verbrugge, Mark // Journal of Applied Electrochemistry;May2007, Vol. 37 Issue 5, p605 

    We derive and implement a battery control algorithm that can accommodate an arbitrary number of model parameters, with each model parameter having its own time-weighting factor, and we propose a method to determine optimal values for the time-weighting factors. Time-weighting factors are...

  • Study of the Lithium Cluster Breakage Kinetics in Germanium. Svetukhin, V. V.; Il’in, P. A. // Technical Physics Letters;Apr2002, Vol. 28 Issue 4, p298 

    The lithium cluster breakage in germanium obeys an exponential kinetics with an activation energy for the particle detachment from cluster equal to 0.31 ± 0.05 eV.


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics