Recent studies, using low-temperature perfusion of rat kidneys, have claimed the existence of renal charge selectivity simply on the basis of the differential excretion rates of uncharged Ficoll and charged proteins. To test for the existence of charge selectivity in vivo, we examined the clearance of negatively charged Ficoll compared with uncharged Ficoll. A short-term approach to steady stat...

Polydisperse Ficoll mixtures have been used to explore glomerular sieving. Ficoll appears to be neither absorbed nor secreted by the renal tubule, and so urinary Ficoll concentrations reflect only the glomerular filtration barrier. The literature is contradictory regarding Ficoll's behavior as an idealized spherical solute. Further definition of Ficoll transport will inform interpretation of in...

The glomerular filtration barrier (GFB) is commonly conceived as a negatively charged sieve to proteins. Recent studies, however, indicate that glomerular charge effects are small for anionic, carboxymethylated (CM) dextran vs. neutral dextran. Furthermore, two studies assessing the glomerular sieving coefficients (θ) for negative CM-Ficoll vs. native Ficoll have demonstrated an increased glome...

The proteinuric actions of protamine sulfate (PS) have classically been, at least partly, attributed to alterations of the negatively charged glomerular endothelial glycocalyx. To investigate whether the charge-selective properties of the glomerular filtration barrier (GFB) would be altered by PS, we assessed the glomerular sieving of conventional, uncharged, polydispersed Ficoll (n-Ficoll) com...

We investigated the effects of superoxide dismutase (SOD) and SOD linked to Ficoll (mol. wt = 400,000) on the changes in pulmonary transvascular fluid and protein exchange following pulmonary microembolism induced with alpha-thrombin. Studies were made in chronically prepared unanesthetized sheep with lung lymph fistulas. Control thrombin challenged sheep (n = 5) were compared to animals infuse...

Nanoparticulate delivery systems for vaccine adjuvants, designed to enhance targeting of secondary lymphoid organs and activation of APCs, have shown substantial promise for enhanced immunopotentiation. We investigated the adjuvant activity of synthetic oligonucleotides containing CpG-rich motifs linked to the sucrose polymer Ficoll, forming soluble 50-nm particles (DV230-Ficoll), each containi...

The extent to which the glomerular basement membrane (GBM) contributes to the charge selectivity of the glomerular capillary wall has been controversial. To reexamine this issue, the size and charge selectivity of filters made from isolated rat GBM were assessed, using polydisperse Ficoll and Ficoll sulfate as test macromolecules. Ficoll sulfate, a novel tracer with spherical shape synthesized ...

Chemokine receptors are distinctively exposed on cells to characterize their migration pattern. However, little is known about factors that may regulate their expression. To determine the optimal conditions for an accurate analysis of chemokine receptors, we compared the expression of CCR2, CCR4, CCR5, CCR6, CXCR3 and CXCR4 on different leukocyte subsets using whole blood (WB) plus erythrocyte ...

Albuminuria in nephrotic states is thought to arise from the formation of large pores in the glomerular capillary wall as large hydrodynamic probes, like Ficoll, have increased fractional clearance. In the present study, we tested for large pore formation in a novel manner. We accounted for the rates of plasma elimination as determined for tritium-labeled tracers of uncharged polydisperse Ficol...

Polydisperse mixtures of dextran or Ficoll have been frequently used as molecular probes for studies of glomerular permselectivity because they are largely inert and not processed (reabsorbed) by the proximal tubules. However, dextrans are linear, flexible molecules, which apparently are hyperpermeable across the glomerular barrier. By contrast, the Ficoll molecule is almost spherical. Still, t...