A model for the control of testosterone secretion
Catherine
Lloyd
Auckland Bioengineering Institute, The University of Auckland
Model Status
This CellML model runs in OpenCell and can reproduce one oscillation (which is true to the published results) but is unable to produce further oscillations. This is probably because there are time delays in the origianl model which as yet can not be described in CellML. The units have been checked and they are consistent with just small equivalencies in pico and nano grams per ml. The CellML model also runs in COR but the long duration of the simulation is not ideal for this tool.
ValidateCellML verifies this model as valid CellML, although unit inconsistencies are detected.
Model Structure
ABSTRACT: We produce here a model to explain the control of testosterone secretion. In this model the hypothalamic secretion of the hormone LHRH (luteinizing hormone releasing hormone) is controlled by a combination of local testosterone concentration and of the local concentration of the pituitary hormone LH (luteinizing hormone). Since LHRH stimulates the release of LH, and LH in turn stimulates the release of testosterone, the three hormones constitute a three-component "feedback" network. We show how this model is able to account for the pulsatility of the release of these three hormones. Furthermore, the model is consistent with results obtained from a wide range of experimental manipulations of the system. For example, it accounts for the changes observed in hormone release patterns after castration. In particular, it follows that no "neural clock", or "neural pulse-generator", is required to force the system into pulsatile behaviour.
model diagram
Schematic diagram of the mathematical model representing the luteinizing hormone releasing hormone (LHRH), luteinizing hormone (LH), and testosterone system. The model has three main components: the hypothalamus which secretes LHRH, the pituitary which responds to LHRH by secreting LH, and the testes which, in responds to LH, secrete testosterone. Finally, LH and testosterone feedback on the hypothalamus to regulate LHRH secretion.
The original paper reference is cited below:
A model for the control of testosterone secretion, Mark Cartwright and Masud Husain, 1986,
Journal of Theoretical Biology
123, 239-250. PubMed ID: 3306160
R
LHRH
luteinizing hormone releasing hormone
$\frac{d R}{d \mathrm{time}}=\mathrm{rR}H-\mathrm{dR}Rx=2.0-\frac{L}{\mathrm{L\_}}+\frac{T}{\mathrm{T\_}}H=\begin{cases}0.0 & \text{if $x< 0.0$}\\ 0.5 & \text{if $x=0.0$}\\ 1.0 & \text{if $x> 0.0$}\end{cases}$
L
LH
luteinizing hormone
$\frac{d L}{d \mathrm{time}}=\mathrm{rL}R-\mathrm{dL}L$
T
testosterone
$\frac{d T}{d \mathrm{time}}=\mathrm{rT}L-\mathrm{dT}T$
testosterone
luteinizing hormone
hypothalamus
pituitary
testis
endocrine
The model has been curated - the model runs in PCEnv and COR and the units have been checked and are consistent. The model produces one oscillation which is true to the published results. However, I can't get it to repeatedly oscillate - I suspect because we need to include the time delays - which CellML can't handle at the moment.
Masud
Husain
The University of Auckland, Auckland Bioengineering Institute
Journal of Theoretical Biology
2007-07-18T00:00:00+00:00
Catherine Lloyd
Catherine
Lloyd
May
2009-05-29T12:38:58+12:00
James
Lawson
Richard
updated curation status, removed reference link in documentation
Catherine Lloyd
keyword
Mark
Cartwright
c.lloyd@auckland.ac.nz
1986-11-00 00:00
The University of Auckland
Auckland Bioengineering Institute
A model for the control of testosterone secretion
123
239
250
Cartwright and Husain's mathematical model for the control of testosterone secretion.
This is a CellML description of Cartwright and Husain's mathematical model for the control of testosterone secretion.
Catherine
Lloyd
May
3306160