ACTION OF PENTOXIFYLLINE ON CYTOSOLIC CALCIUM AND ON THE ERYTHROCYTICMORPHOLOGY DURING AGING

Cytosolic calcium is an important parameter of cell functionality and its concentration is determined by homeostatic mechanisms which are AT P dependent. When an energetic depletion occurs, as in the case of isc haemia, uncontrolled accumulation of ion in the cytosol with a reducti on of membrane deformability, and the modification of the physiologic shape of erythrocyte can be noted. Pentoxifylline has a theological ef fect acting on energetic metabolism of red cells. Our objective was to verify the action of pentoxifylline on calcium concentration and on t he erythrocytic morphology of cell ageing. We used as ageing model the conservation of blood in vitro: 3 blood samples (from 6 taken by 8 no rmal subjects), have been incubated with pentoxifylline (1.4X10-4M). W e dosed cytosolic calcium and evaluated cell morphology in 2 samples ( with and without pentoxifylline) in basal conditions, after 4 and afte r 8 hours of conservation at 37 degrees C. Dosage of intraerythrocytic calcium was made with FURA2-AM (Calbiochem) according to the David-Du filho method. Erythrocytic morphology was evaluated with an optical mi croscope following the Zipursky method. Results showed a reduction of the increase of cytosolic calcium and a major conservation of the eryt hrocytic physiologic morphology in samples incubated with pentoxifylli ne after 4 and 8 hours in comparison with Control samples. These obser vations confirm that pentoxifylline delays uncontrolled accumulation o f calcium which, in ageing, causes cell suffering and keeps its morpho logic physiology for a longer time.