BENEFICIAL IMPACT OF DIPYRIDAMOLE AND DIDS ON ERYTHROCYTE MEMBRANE AT MEMBRANOPATHY

Spectrin and the band 3, major proteins of human erythrocyte membrane, are altered in patients with hereditary spherocytosis (HS). The band 3 is implicated in the permeability transition of erythrocyte membranes (EM) at 61°C (Tg), and its monomer is specifically stabilized by DIDS (4,4´-diisothiocyanostilbene-2,2´-disulphonate) and Dipyridamole (2,6-bis(diethanolamino)-4,8dipiperidinopyrimido[5,4-d] pyrimidine). PURPOSE. To study in vitro the impact of DIDS and dipyridamol on the band 3 in anemic patients as revealed by the changes in the Tg temperature. METHODS. We used thermal analysis of the impedance (70 kHz) of erythrocytes suspended in isotonic 30 mM NaCl/mannit media in order to detect permeability transition at Tg and the heat denaturation of spectrin at 49.5 °C. RESULTS: In patients (n = 8) with HS the Tg transition was detected at 56-57°C and accompanied by severe instability of EM after the spectrin denaturation temperature. DIDS (30 μM, irreversible) and dipyridamole (100 μM, reversible) increased the Tg to about 60°C and subdued the preceding membrane instability. CONCLUSION. Dipiridamole and DIDS both stabilized the structure of EM from patients with HS. Thermal dielectroscopy is useful test for population screening of asymptomatic forms of HS.