Affiliations: University of Lisbon Medical School, Santa Maria Hospital, 1649-028 Lisbon, Portugal | Institute of Biochemistry, Institute of Molecular Medicine, University of Lisbon Medical School, 1649-028 Lisbon, Portugal
Note: [] Corresponding author: José Pedro Almeida, Instituto de Bioquímica, Unidade de Biopatologia Vascular, Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Edifício Egas Moniz, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal. Tel.: +351 91 8985450; Fax: +351 21 7999477; E-mail: [email protected].
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.
Keywords: Dithiothreitol, hemorheology, red blood cell, redox status
