Effect of piracetam on Ca²⁺-induced K⁺ efflux from sickle cells

Article type: Research Article

Authors: Stuart, J.^{a; *} | Stone, P.C.W.^a | Nash, G.B.^a | Ellory, J.C.^b

Affiliations: [a] Department of Haematology, Medical School, University of Birmingham, Birmingham B15 2TJ, UK | [b] Department of Physiology, University of Oxford, Oxford OX1 3PT, UK

Correspondence: [*] Correspondence to Professor J. Stuart.

Note: [] Accepted by: Editor M.R. Boisseau (Received by Executive Editorial Office 1.8.1990)

Abstract: Piracetam has been reported to have a protective rheological effect on sickle cells. When sickle cells were subjected to cyclical oxygenation-deoxygenation for 15 hours in Ca2+-containing buffer, there was a loss of cell filterability through pores of 5 µm diameter and an increase in mean cell haemoglobin concentration and percentage irreversibly sickled cells. These changes were consistent with entry of Ca2+, activation of the Gardos channel in the sickle cell membrane, and loss of cell K+ and water. Piracetam at 100 mmol/l had a significant protective rheological effect. When sickle cells containing 86Rb were loaded with Ca2+ using the Ca2+-ionophore A23187, however, the consequential efflux of K+ (86Rb) through the Gardos channel was not inhibited by 10 or 100 mmol/l piracetam. The action of piracetam in preventing dehydration of sickle cells would not therefore seem to be due to inhibition of the Gardos channel.

Keywords: Rheology, erythrocyte deformability, sickle cell anemia

DOI: 10.3233/CH-1990-10510

Journal: Clinical Hemorheology and Microcirculation, vol. 10, no. 5, pp. 535-540, 1990