REDUKCJA POZIOMU CHOLESTEROLU I NORMALIZACJA PŁYNNOŚCI BŁONY ERYTROCYTARNEJ POD WPŁYWEM PRAWASTATYNY I EPIKATECHINY U PACJENTÓW Z HIPERCHOLESTEROLEMIĄ TYPU II- BADANIA IN VITRO.

The aim of the study was to compare the effects in vitro of pravastatin and epicatechin on the structural parameters of erythrocyte membrane in patients with type-2 hypercholesterolemia. Material and methods. The study involved 20 patients with type-2 hypercholesterolemia (mean age 46±14). The control group consisted of 15 healthy individuals (mean age 48±10). Erythrocytes obtained from patients and healthy individuals were incubated with pravastutin (concentrations: 9µM, 90µM) and epicatechin (concentrations: 5µM, 10µM). In plasma membranes of erythrocytes we assessed the cholesterol content (by method of llcy), the level of TBARS (by method of Stocks and Dormandy) and the membrane fluidity by means of 5-DSA (paramagnetic resonance). Results. In erythrocytes of patients with hypercholesterolemia type-2 comparing to the control group significantly higher mean values of membrane cholesterol content (3,64±0,77 vs. 2.11±0,57 mmol/l pc), the order parameter S (0,748±0,011 vs. 0,770±0,013) and TBARS (1,48±0,47 vs. 3,40±0.75 mmol/g Hb) were observed. Phosphorus content in membrane phospholipids (I,73±0,34 vs. 2,51±0,8 mmol/1 pc) and molar ratio cholesterol/phospholipids (1,22±0,64 vs 1,45±0.25) were also higher in patients than in healthy volunteers. After incubation of erythrocytes with pravastatin and epicatechin the membrane fluidity at the depth of 5th carbon atom has improved, the membrane cholesterol concentration has decreased. Epicatechin influenced considerably the level of TBARS in comparison to pravastatin. Conclusions: 1) Epicatechin in vitro better decreases the membrane cholesterol content in patients with type-2 hypercholesterotemia than pravastatin. Both substances cause an increase in the fluidity of plasma membrane of erythrocytes. 2) Pravastatin, in vitro, in opposite to epicatechin does not influence on lipid peroxidation in erythrocytes of patients with type-2 hypercholesterolemia. [ABSTRACT FROM AUTHOR]