Mathematical analysis and digital simulation of the control of erythropoiesis

Abstract

A mathematical model is presented which represents the control system for erythropoiesis. In the model, it is postulated that the rate of erythropoiesis is controlled by a hormone, erythropoietin, which is released from the kidney in response to reduced renal oxygen supply. Equations are developed which relate erythropoietin release to arterial oxyhemoglobin concentration, and hemoglobin production to plasma erythropoietin concentration, with appropriate time delays. Effects of changes in plasma volume during hypoxia are included. The model is used with a digital computer to simulate the dynamic response of the erythropoietic system to a step decrease in the pO2 of inspired air. The response of the model compares favorably with experimental data obtained from mice subjected to different degrees of hypoxia.