MacGregor, Leng, 2005

Model Status

This particular CellML model describes the pituitary model of the published article. The units have been checked and are consistent and the model runs in PCEnv to replicate the published results (as shown in figure 3B of the paper)..

Model Structure

In most mammals, including humans, growth hormone (GH) is secreted in a pulsatile pattern, which is regulated by two hypothalamic peptides; growth hormone-releasing hormone (GHRH) and somatostatin. The former stimulates GH secretion while the latter inhibits it. The activity of the hypothalamic neuroendocrine neurones is affected by feedback from GH and somatomedins, including activation of somatostatin release and possibly inhibition of GHRH release. Furthermore, there is evidence that somatostatin neurones may inhibit the activity of GHRH neurones.

In their 2005 model, MacGregor and Lend use mathematical equations to describe these biological features and present a model of the hypothalamic network that controls GH secretion (see the figure below).

The complete original paper reference is cited below:

Modelling the hypothalamic control of growth hormone secretion, D. J. MacGregor and G. Leng, 2005, Journal of Neuroendocrinology , volume 17, 788-803. (Full text (HTML) and PDF versions of the article are available to subscribers on the Journal of Neuroendocrinology website.) PubMed ID: 16280026

A schematic diagram of the different components and connections in the growth hormone secretory system. Somatostatin (SOS) inhibits the secretion of both growth hormone-releasing hormone (GHRH) and growth hormone (GH). After a delay, GH feeds back to prime the pool of releasable somatostatin, resulting in the bulk release of somatostatin, which in turn allows further GHRH release and and another burst of GH.