Modeling of testosterone regulation by pulse-modulated feedback.
The continuous part of a hybrid (pulse-modulated) model of testosterone (Te) feedback regulation in the human male is extended with infinite-dimensional and nonlinear blocks, to obtain the dynamics that better agree with the hormone concentration profiles observed in clinical data. A linear least-squares based optimization algorithm is developed for the purpose of detecting impulses of gonadotropin-releasing hormone (GnRH) from measured concentration of luteinizing hormone (LH). The estimated impulse parameters are instrumental in evaluating the frequency and amplitude modulation functions parameterizing the pulse-modulated feedback. The proposed approach allows for the identification of all model parameters from the hormone concentrations of Te and LH. Simulation results of the complete estimated closed-loop system exhibiting similar to the clinical data behavior are provided.
Department of Information Technology, Uppsala University, Box 337, SE-751 05, Uppsala, Sweden, per.mattsson@it.uu.se.
Per
P
Mattsson
Alexander
A
Medvedev
D000465:Algorithms; D003198:Computer Simulation; D025461:Feedback, Physiological; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D008954:Models, Biological; D013739:Testosterone / Q000378:metabolism*
D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D007986:Luteinizing Hormone