Relation between palmitic acid concentration in the erythrocyte membranes and insulin binding

Background. Several previous reports have demonstrated that plasma membrane composition and fatty acids can modulate insulin receptor activity in vitro. In the present study the correlations between fatty acids contained in the membrane and insulin binding properties were studied on erythrocytes obtained from normal subjects. The aim was to evaluate the influence of individual fatty acids of the cell membrane on insulin binding properties. Methods. Erythrocytes obtained from 13 normal blood donors were used to measure both the insulin binding and the membrane fatty acids. Binding was measured with the competition curve and the fatty acids concentration with gascromathography. Statistical evaluation was carried out using linear regression analysis. Results. The main result of the present study is that palmitic acid concentration in the membrane correlates with observed B(MAX)/2 value (r = 0.64; p < 0.02). No significant correlation was found between other fatty acids of the membrane and insulin binding parameters. Conclusions. Our data indicate that palmitic acid content of the plasma membrane can be an important regulator of insulin binding affinity.