Nisoldipine improves the impaired erythrocyte deformability correlating with elevated intracellular free calcium‐ion concentration and poor glycaemic control in NIDDM

Abstract
Aims To explore the mechanisms underlying the impaired erythrocyte deformability (RBC-df) in diabetic patients, the relationship between erythrocyte intracellular free calcium-ion concentration ([Ca2+]i) and RBC-df, and the effects of Ca2+-channel blocker on [Ca2+]i and RBC-df were evaluated. Methods Forty-eight patients with NIDDM and 24 control subjects were enrolled in this study. [Ca2+]i was determined using fura-2, and RBC-df by filtration method expressed as Deformability Index (DI). Erythrocytes were treated with nisoldipine to evaluate the effects of a Ca2+-channel blocker. Results [Ca2+]i was significantly higher (82.6 (78.0–87.2) vs 76.6 (74.3–81.2) nmol lRBC−1, P1c and [Ca2+]i (r=0.38, P1c and DI (r=−0.51, P2+]iand DI (r=−0.42, P1c and [Ca2+]i as independent determinants for the impaired RBC-df. Nisoldipine treatment in vitro significantly decreased [Ca2+]i, and significantly improved RBC-df. Conclusions These data indicate that the impaired RBC-df in NIDDM may at least partly be attributed to the elevated [Ca2+]i and poor glycaemic control. In addition, favorable effects of a Ca2+-channel blocker on both [Ca2+]i and RBC-df have been demonstrated.