Computer Analysis of the Binding Reaction between hCG and Gonadotropin Receptors of the Rat Testis

  • J. M. Ketelslegers
  • G. D. Knott
  • K. J. Catt
Part of the Current Topics in Molecular Endocrinology book series (CTME, volume 1)


The presence of specific high-affinity binding sites for luteinizng hormone (LH) and human chorionic gonadotropin (hCG) has been established in the Leydig cells of the rat testis (1–3). The binding of hCG to these receptors has been demonstrated to be a saturable process, and the velocity of binding shows marked temperature dependence (3). Analysis of gonadotropin binding data by Scatchard plots previously indicated the presence of a single class of binding sites (3). To define more accurately the association constant and the rate constants of this hormone-receptor interaction, more detailed equilibrium and kinetic experiments were performed, and the data analyzed with an interactive non-linear curve fitting program. This analytical system (MLAB) has been previously described (4, 5), and runs on a PDP-10 digital time-sharing computer. This approach has the advantage of permitting the use of complex models while performing simultaneous fits to multiple sets of data, without a significant increase in the complexity of the computation procedure. In particular, data expressing the total bound hormone and the non-specifically bound hormone as functions of the initial hormone concentration could be analyzed simultaneously, with computation of specific binding from the results of the simultaneous fitting process.


Hormone Concentration Dissociation Experiment Association Rate Constant Gonadotropin Receptor Bovine Corpus Luteum 
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Copyright information

© Plenum Press, New York 1974

Authors and Affiliations

  • J. M. Ketelslegers
    • 1
    • 2
  • G. D. Knott
    • 1
    • 2
  • K. J. Catt
    • 1
    • 2
  1. 1.Section on Hormonal RegulationNational Institute of Child Health and Human DevelopmenUSA
  2. 2.Division of Computer ResearchNational Institutes of HealthBethesdaUSA

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