Sotiris, A. and Prokopiou, S. A. and Byrne, H. M. and Jeffrey, M. R. and Robinson, R. S. and Mann, G. E. and Owen, M. R. (2013) Mathematical analysis of a model for the growth of the bovine corpus luteum. Journal of Mathematical Biology . (Submitted)

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Abstract
The corpus luteum (CL) is an ovarian tissue that grows in the wound space created by follicular rupture. It produces the progesterone needed in the uterus to maintain pregnancy. Rapid growth of the CL and progesterone transport to the uterus require angiogenesis, the creation of new blood vessels from preexisting ones, a process which is regulated by proteins that include fibroblast growth factor 2 (FGF2).
In this paper we develop a system of timedependent ordinary differential equations to model CL growth. The dependent variables represent FGF2, endothelial cells (ECs), luteal cells, and stromal cells (like pericytes), by assuming that the CL volume is a continuum of the three cell types. We assume that if the CL volume exceeds that of the ovulated follicle, then growth is inhibited. This threshold volume partitions the system dynamics into two regimes, so that the model may be classified as a Filippov (piecewise smooth) system.
We show that normal CL growth requires an appropriate balance between the growth rates of luteal and stromal cells. We investigate how angiogenesis influences CL growth by considering how the system dynamics depend on the dimensionless EC proliferation rate, p5. We find that weak (low p5) or strong (high p5) angiogenesis leads to ‘pathological’ CL growth, since the loss of CL constituents compromises progesterone production or delivery. However, for intermediate values of p5, normal CL growth is predicted. The implications of these results for cow fertility are also discussed. For example, inadequate angiogenesis has been linked to infertility in dairy cows.
Item Type:  Article 

Subjects:  D  G > General 
Research Groups:  Oxford Centre for Collaborative Applied Mathematics 
ID Code:  1681 
Deposited By:  Peter Hudston 
Deposited On:  23 Feb 2013 08:42 
Last Modified:  29 May 2015 19:22 
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