A mathematical model of the volume, pH, and ion content regulation in reticulocytes. Application to the pathophysiology of sickle cell dehydration.

Abstract

We developed a mathematical model of the reticulocyte, seeking to explain how a cell with similar volume but much higher ionic traffic than the mature red cell (RBC) regulates its volume, pH, and ion content in physiological and abnormal conditions. Analysis of the fluxbalance required by reticulocytes to conserve volume and composition predicted the existence of previously unsuspected Na '-dependent Cl -entry mechanisms.

Investigating Interferences of a Whole-Blood Point-of-Care Creatinine Analyzer: Comparison to Plasma Enzymatic and Definitive Creatinine Methods in an Acute-Care Setting

“…) (12 ), with the specific gravity of blood reduced from 1.090 to 1.050 to account for membrane components of red blood cells (RW ϭ 0.715 at MCHC 335 g/L) (12,13 ).…”

Effects of deoxygenation on active and passive Ca2+ transport and on the cytoplasmic Ca2+ levels of sickle cell anemia red cells.

“…Sickling permeabilizes the cell membranes to mono-and divalent cations (2,(4)(5)(6)(7) producing secondary abnormalities of RBC ion and water contents. The ion and water shifts are mediated mostly by large-capacity K+ transporters, such as Ca2 -sensitive K channels and K:C1 carriers, which can both be directly or indirectly stimulated by increased intracellular ionized Ca2" concentration (QCa2+]j), resulting in rapid net loss of KCl and water (8).…”

KCl cotransport activity in light versus dense transferrin receptor-positive sickle reticulocytes.

“…Lew et al. (6) have proposed a complex series of cellular events initiated by a deoxygenation-induced leak of Ca into reticulocytes, followed by Ca-dependent K efflux, intracellular acidification, and finally activation of KCl cotransport. This model is based on the in vitro requirements for deoxygenation and Ca++ to induce dehydration of light reticuloctyes, as well as the pH-dependent KCl cotransport activity of young cells (7).…”