Some Inexact Methods for the Analysis of Transport Kinetics Using Dual Tracers

  • I. Christopher H. Smith


Paired tracer dilution studies have provided a revolution in understanding the cellular transport of metabolites and other biologically active substances. The potency of the method lies in the twin features of selectivity and speed. Selectivity is obtained by the test tracer being paired with a reference tracer which, ideally, differs only in the features under investigation. Speed is obtained by perfusion against or close to the active site of transport. Over the last forty years the techniques have been developed by many laboratories using whole organ perfusion of the capillary bed to give rapid access to the transporting cells (see Yudilevich, this book). More recently the perfusion of cultured cells on carrier beads (see Mann, Sherrif, Toothill and Pearson, this book) have proved to allow a similar access time. It is thus rather surprising to discover that there is no consensus of how to interpret the results obtained by these methods. Old equations have been applied to new techniques with scant regard for the fundamentals of the method. New analytical methods have come, and gone, without apparently being able to fully exploit the obvious experimental power of the dilution technique. This article briefly describes the analytical problems and considers the options available to overcome them.


Test Tracer Cellular Transport Extravascular Space Test Molecule Space Marker 
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  1. Bassingthwaighte, J.B., and Goresky, C.A., 1984, Modelling in the analysis of solute and water exchange in the microvasculature, in: Handbook of Physiology, Sec. 2, eds. Renkin, E.M., and Michel, C.C., Am.Physiol. Soc., Bethesda.Google Scholar
  2. Bassingthwaighte, J.B., King, R.B., and Roger, S.A., 1989, Fractal nature of regional myocardial flow heterogeneity, Circ. Res., 65: 578–590.PubMedCrossRefGoogle Scholar
  3. Bassingthwaighte, J.B., and Sparks, H.V., 1986, Indicator dilution estimation of capillary endothelial transport, Ann.Rev. Physiol., 48: 321–334.CrossRefGoogle Scholar
  4. Boyd, C.A.R., and Parsons, D.S., 1979, Movements of monosaccharides between blood and tissue of vascularly perfused small intestine, J. Physiol., 287: 371–391.PubMedGoogle Scholar
  5. Gorman, M.W., Bassingthwaighte, J.B., Olsson, R.A., and Sparks, H.V., 1986, Endothelial cell uptake of adenosine in canine skeletal muscle, Am. J. Physiol. 250: H482 - H489.Google Scholar
  6. Mann, G.E.M., Norman, P.S.R., and Smith, I.C.H., 1989, Amino acid efflux in he isolated perfused rat pancreas: trans-stimulation by extracellular amino acids, J. Physiol., 416: 485–502.PubMedGoogle Scholar
  7. Mann, G.E.M., and Yudilevich, D.L., 1975, Sarcolemmal metabolite transport and neuronal uptake of biogenic amines in the perfused rabbit heart, in: “Carrier-mediated Transport of Solutes from Blood to Tissue”, Yudilevich, D.L., and Mann, G.E.M.. eds., Longman, New York.Google Scholar
  8. Norman, P.S.R., and Mann, G.E.M., 1986, Transport characteristics of system A in the rat pancreatic epithelium analyzed using the specific non-metabolised amino acid analogue 2–methylaminoisobutyric acid, Biochim. Biophys. Acta, 943: 541–546.Google Scholar
  9. Smith, I.C.H., 1982, A graphical assessment of capillary extraction for saturable transport, J. Physiol., 330: 42P - 43 P.Google Scholar
  10. Smith, LC.H., 1985, An interpretation of single-pass uptake curves for measuring cellular transport, in: “Carrier-mediated Transport of Solutes from Blood to Tissue”, Yudilevich, D.L., and Mann, G.E.M.. eds., Longman, New York.Google Scholar
  11. Yudilevich, D.L., 1985, Rapid cellular uptake from the microcirculation, in: “Carrier-mediated Transport of Solutes from Blood to Tissue”, Yudilevich, D.L., and Mann, G.E.M.. eds., Longman, New York.Google Scholar
  12. Yudilevich, D.L., 1989, Blood-tissue transport of substrates in the heart: studies by single circulation tracer dilution, Int. J. Microcirc. Clin. Exp., 8: 397–409.PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1991

Authors and Affiliations

  • I. Christopher H. Smith
    • 1
  1. 1.Biomedical Sciences DivisionKing’s College LondonLondonUK

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