title: Is the "pool-fraction" paradigm a valid model for assessment of in vivo turnover in non-steady state?
abstract: Quantification of in vivo turnover of endogenous substances in nonsteady state is of fundamental importance for understanding a variety of physiological and clinical metabolic situations. Toward this end, a pool-fraction model has become a paradigm in the glucose and ketone body areas. We discuss the basic assumptions on which the pool-fraction model is based and the criteria on which it has been validated. Specific comments are then made on its current and potential use for quantifying the non-steady-state turnover of glucose, ketone bodies, and insulin. We conclude that the quantitative reliability of predictions provided by the pool-fraction model is quite poor and that new developments are needed for quantifying the non-steady-state situation.
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002477:Cells / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D007657:Ketone Bodies / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008433:Mathematics; D008954:Models, Biological
chemical_list: D001786:Blood Glucose; D007657:Ketone Bodies; D005947:Glucose