2,5-Hexanedione modifies skeletal proteins of the red blood cells and increases the binding of hemoglobin to the membrane.
The effects of 2,5-hexanedione (2,5 HD) on skeletal proteins of red blood cells (RBCs) were investigated both in vitro (human RBCs) and in vivo in male Sprague-Dawley rats which had been treated with the drug for several days. We found that 2,5 HD induced the following major changes in the electrophoretic pattern of the skeletal proteins: (i) the appearance of high-molecular weight bands, (ii) a dose-dependent decrease in spectrin Bands 1 and 2, and (iii) a dose-dependent increase in the amount of hemoglobin (Hb) associated with the membrane. Membranoskeletons, prepared from resealed ghosts which had been previously treated with 2,5 HD, were able to bind an increased amount of Hb from untreated RBCs, thus suggesting a drug-induced modification of the membrane. Extraction of spectrin and actin from ghosts did not remove the membrane-bound Hb and, furthermore, Hb bound to 2,5 HD-treated membranes mainly bearing Band 3 and free of peripheral proteins. These data suggested a 2,5 HD-induced modification of an intrinsic membrane protein, probably Band 3. This hypothesis was consistent with the observation that 2,5 HD also induced a modification of Band 3 aminogroups, as evidenced by a dose-dependent decrease in the binding of eosin probes. Furthermore, RBCs treated in vitro with 2,5 HD bound an increased amount of autologous immunoglobulins (IgG). As reported by Kay and Low et al. the binding of autologous IgG is a phenomenon associated with the aging process of RBCs and may involve a modification of Band 3. Our data show that RBCs treated with 2,5 HD acquired various characteristics of senescent cells such as spectrin cross-linking, Hb-membrane binding and increased IgG binding, and suggest that 2,5 HD treatment might affect RBC survival.
Laboratorio di Igiene Ambientale, Istituto Superiore di Sanita', Roma, Italy.
C
C
Mallozzi
G
G
Scorza
N
N
Frontali
M
M
Minetti
D000818:Animals; D001798:Blood Proteins / Q000187:drug effects* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004905:Erythrocyte Aging / Q000187:drug effects; D004910:Erythrocyte Membrane / Q000378:metabolism; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism*; D006588:Hexanones / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007659:Ketones / Q000494:pharmacology*; D008297:Male; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains
D001798:Blood Proteins; D006454:Hemoglobins; D006588:Hexanones; D007659:Ketones; C011269:2,5-hexanedione