EFFECT OF PERINDOPRIL THERAPY ON FLUIDITY AND POTENTIAL OF ERYTHROCYTE-MEMBRANE FROM INDIVIDUALS WITH CORONARY HEART-DISEASE

Erythrocyte membrane fluidity and membrane potential were measured in patients suffering from coronary heart disease (CHD) and treated with perindopril. Membrane fluidity was determined using electron paramagne tic resonance (EPR) spectroscopy, and membrane potential was evaluated using potential-sensitive fluorescent dyes. CHD does not change membr ane fluidity at the depth of the 5 carbon in the fatty acid chain of m embrane phospholipids. However the hydrophobic core of the membrane is altered in CHD. For 19 CHD patients, the correlation times tau(B) and tau(C) of a spin label 16DS were higher than for controls: tau(B)=(1. 84+/-0.04)x10(-9) s and tau(C)=(2.54+/-0.04)x10(-9) s vs tau(B)=(1.62/-0.06)x10(-9) s; and tau(C)=(2.24+/-0.07)x10(-9) s (results given as mean +/- SEM). Such results indicate the increased microviscosity in h ydrophobic regions of CHD erythrocyte membranes in comparison with con trols. Perindopril therapy partly abolished these changes. The membran e potential of CHD red blood cells -17.89+/-1.36 mV was higher than th e control value -9.83+/-0.59 mV. Perindopril treatment shifted the mem brane potential value to -13.45+/-0.99 mV when measured after a single dose of the drug, or even depolarized the membrane after 7 days of th erapy -4.95+/-0.73 mV. It is concluded that the erythrocyte membrane i s more rigid and hyperpolarized in CHD, and perindopril therapy partly abolishes these changes as early as 3 h after administration.