Red cell Ca2+ content (total and cytosolic) and erythrocyte membrane fluidity in several clinical conditions

Abstract

In several groups of subjects with different clinical conditions: vascular atherosclerotic disease (VAD), VAD with diabetes mellitus of type 2 (NIDDM), diabetes mellitus of type 1 and diabetes mellitus of type 2 without macrovascular complications, essential hypertension and chronic renal failure (CRF), we evaluated the red cell Ca2+ content (total and cytosolic), the erythrocyte membrane fluidity and the correlations between them. The total red cell Ca2+ content does not differentiate normals from VAD subjects with and without NIDDM and normals from diabetics of type 1 and 2, but it does discriminate normals from hypertensives and normals from CRF subjects. The cytosolic red cell Ca2+ content does not distinguish normals from VAD subjects, while it clearly differentiates normals from VAD subjects with NIDDM, normals from diabetics of type 1 and 2, normals from hypertensives and normals from CRF subjects. In all these clinical conditions the erythrocyte membrane fluidity is reduced compared to controls; the erythrocyte membrane fluidity is not related to the total red cell Ca2+ content in each of these clinical conditions, while it is related to the cytosolic red cell Ca2+ content in type 2 diabetics, in hypertensives and in CRF subjects.