Modulation of hemorheological parameters by the erythrocyte redox thiol status

Abstract

Background: There is growing knowledge about the association between hemorheological blood disorders and compromised microcirculation in erythrocyte abnormalities. Effects of the non-neuronal cholinergic elements, especially acetylcholinesterase, on the erythrocyte hemorheological parameters were characterized in the past. However, alterations of these parameters have not been studied under the influence of the cellular redox thiol status.Methods: Aliquots of venous blood from ten healthy male subjects were incubated in vitro with increasing concentrations of a thiol reducer agent (dithiothreitol 1, 10, 50 µM final concentrations) in the presence and absence of acetylcholinesterase substrate (acetylcholine) or inhibitor (velnacrine maleate). The following parameters were determined in all blood samples aliquots: erythrocyte aggregation, erythrocyte deformability and lipid membrane fluidity. Blood smears were performed.Results: Dithiothreitol induces no significant changes on the hemorheological behaviour of human red cells. Upon intracellular thiol stimulation, the presence of AChE effectors (either acetylcholine or velnacrine) decreases erythrocyte aggregation and elongation indexes.Conclusion: The addition of DTT to blood samples aliquots, contributing to the redox thiol status, is not directly involved in the modulation of erythrocyte rheological properties. However, upon acetylcholinesterase modulation by its substrate or inhibitor, changes on the hemorheological parameters are triggered by DTT. Associated pharmacological interest is considerable to address the hemorheology-hemostasis-microcirculation triad disorders.

Erythrocyte as a link between basic and clinical research

“…The stimulation of the erythrocyte redox status by adding dithiothreitol in blood samples taken from healthy humans with normal values of plasma fibrinogen, revealed no changes in RBCs aggregation [1].…”

Erythrocyte Nitric Oxide

“…When stimulating the erythrocyte redox thiol status by loading dithiothreitol (DTT), there is a decreased NO efflux concomitant with increased levels of nitrite, nitrate and GSNO [50]. It is well known that dithiothreitol induces band 3 dephosphorylation and a dephosphorylated state accounts for the AChE inhibitors and fibrinogen effects on red cells [17,30,49].…”

“…The addition of different concentrations of the lipoprotein sub-fractions' LDL/HDL seems not to favor hemoglobin auto-oxidation. Superoxide anion will be formed from the auto-oxidation of hemoglobin, but without its generation plus unchanged values of peroxynitrite concentrations it was evidenced that when the thiol status of erythrocyte was maintained in normal range, no alterations were verified in erythrocyte deformability [50].…”

A new xanthene‐based two‐photon fluorescent probe for the imaging of 1,4‐dithiothreitol (DTT) in living cells

“…However, DTT also could induce the damage to peptides, proteins and DNA, and result in the destruction and dysfunction of some biological macromolecules . Co‐existing with transition metals, DTT can be liable to induce oxidative damage of biomolecules . Therefore, development of an efficient method for the real‐time detection of DTT levels is of great significance for the safe handling of this important material and study of toxicity to humans.…”