Endometriosis: A parametric analysis of a phenomenological-based endometrial model

This article presents the parametric analysis of two coupled models that describe sexual hormonal dynamics and endometrium growth in the menstrual cycle. The endometrial model uses the Monod equation as a constitutive equation in the mass balance of the proliferative and secretory cells. The parameters kpro and ksec in Monod equation can be interpreted as estrogen and progesterone effect, respectively, on the maximum growth rate of the endometrial tissue. These parameters are modified to investigate their impact on the dynamic behavior of endometrial volume. An imbalance between kpro and ksec, can generate an overgrowth of the endometrium, similar to the devolopment of endometriosis and therefore, an imbalance between the levels of estrogen and progesterone -an unopposed estrogen condition-becomes the scenario enhancing the pathology, rather than an isolated estrogen effect. Analysis of the model gives a possible explanation of the dynamics of endometriosis.