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<!--  FILE :  smith_model_1980.xml

CREATED :  18th July 2007

LAST MODIFIED : 18th July 2007

AUTHOR :  Catherine Lloyd
          Bioengineering Institute
          The University of Auckland
          
MODEL STATUS :  This model conforms to the CellML 1.1 Specification.

DESCRIPTION :  This file contains a CellML description of Smith's 1980 mathematical model for the hypothalamic regulation of pituitary secretion of luteinizing hormone - feedback control of gonadotropin secretion. 

CHANGES:  
  
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  <title>Hypothalamic regulation of pituitary secretion of luteinizing hormone. II. Feedback control of gonadotropin secretion</title>
  <author>
    <firstname>Catherine</firstname>
          <surname>Lloyd</surname>
    <affiliation>
      <shortaffil>Bioengineering Institute, University of Auckland</shortaffil>
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  <sect1 id="sec_structure">
  <title>Model Structure</title>

<para>
In human males the secretion of luteinizing hormone (LH) from the anterior pituitary gland is principally controlled by luteinizing hormone releasing hormone (LHRH) which, itself, is secreted by the hypothalamus.  LH in turn influences the secretion of testosterone by the testes, which then has a feedback effect on secretion of its precursor hormones LHRH and LH. 
</para>

<para>
In the paper described here, William Smith proposes a simple mathematical model incorporating a negative feedback loop to describe the kinetics of the hormone cascade in the secretion of testosterone (as summarised in the figure below).
</para>

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<caption>Schematic diagram of the mathematical model representing the male hypothalamic-pituitary-gonadal system.  The model has three main components: the hypothalamus which secretes luteinizing hormone releasing hormone (LHRH), the pituitary which responds to LHRH by secreting luteinizing hormone (LH), and the gonads (or testes) which, in responds to LH, secrete testosterone.  Finally, LH and testosterone feedback on the hypothalamus to regulate LHRH secretion.</caption>
</informalfigure>

<para>
The complete original paper reference is cited below:
</para>

<para>
<ulink url="http://www.springerlink.com/content/pu11363366022540/?p=3e13cfd941d04c37b73466066437cd18&amp;pi=2">Hypothalamic regulation of pituitary secretion of luteinizing hormone. II. Feedback control of gonadotropin secretion</ulink>, William R. Smith, 1980, <ulink url="http://www.springerlink.com/content/119979/">
            <emphasis>Bulletin of Mathematical Biology</emphasis>
          </ulink>, 42, 57-78.  (A <ulink url="http://www.springerlink.com/content/pu11363366022540/fulltext.pdf">PDF</ulink> version of the article is available to journal subscribers on the <emphasis>Bulletin of Mathematical Biology</emphasis> website.)  <ulink url="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&amp;cmd=Retrieve&amp;dopt=AbstractPlus&amp;list_uids=6986927&amp;query_hl=1&amp;itool=pubmed_docsum">PubMed ID: 6986927</ulink>
</para>

</sect1>
</article>
</documentation> 





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