Erythropoietin distribution

Bristow, A., and Charton, E. (1999). Assessment of the suitability of a capillary zone electrophoresis method for determining isoform distribution of erythropoietin. Pharmeuropa 11(2), 290—300. 

The amount of a substance that can enter the brain by the exdacellular pathw ays is small. However, this route may be therapeutically relevant for compounds that have favorable peripheral pharmacokinetics, such as a long serum half-life and a small volume of distribution (Banks, 2004). Therapeutic antibodies and erythropoietin can access the brain by v ay of the extracellular pathways (Banks et al., 2004a Banks et al., 2002 Banks et al., 2005a Kozlowski et al., 1992) and this may underlie their therapeutic benefits (Alafaci et al., 2000 Ehrenreich et al., 2002 Erbyraktar et al., 2003 Morgan et al., 2000 Janus et al., 2000 DeMattos et al., 2002 Farr et al., 2003 Hock et al., 2003). 

Recent research on the speciation and protein binding characteristics of aluminum has led to a better insight in the mechanisms underlying the element s tissue distribution and toxicity [33,34]. In this context, the provocative hypothesis linking the widespread use of erythropoietin to the increasing prevalence of adynamic bone disease is of particular interest [35]. 

Figure 1. Block diagram of a model for the control of erythropoiesis (HbO), oxyhemoglobin concentration Vi, viscosity factor (HbO), effective oxyhemoglobin concentration R, rate of erythropoietin release (E), plasma erythropoietin concentration E0, normal plasma erythropoietin concentration V , distribution volume for erythropoietin P, rate of hemoglobin production MT, erythrocyte maturation time L, rate of hemoglobin loss TH, total circulating hemoglobin (Hb), blood hemoglobin concentration Vb, blood volume Vp, plasma volume Vp0, normal plasma volume Vpf, steady-state hypoxic plasma volume MCV, mean corpuscular volume MCH, mean corpuscular hemoglobin k, constant...

A second study, that of Liebelt et al. (1999), found negative association of erythropoietin with PbB in 86 children, aged from 1 to 16 years. This difference from the former study probably relates to smaller sample size, a different age range and age distribution, and less control for age and other factors. 

---