Concentration and reactivity of the sulphydryl group population on the membrane of intact erythrocytes in patients with rheumatoid arthritis.

Abstract

The sulphydryl population on erythrocyte membrane is shown to vary as a function of the nutritional status of the cell. When an assay based on reaction with Eliman's reagent and controlled conditions were used the mean values (SEM) for the sulphydryl population on the membranes of normal erythrocytes incubated overnight in the presence and absence of glucose were found to be 3-29 (0.27) and 2 56 (0.25) million sulphydryl functions per cell respectively. Under identical conditions rheumatoid erythrocytes incubated in the presence and absence of glucose were found to have a significantly lower sulphydryl population-1-54 (0.08) and 1-15 (0.08) million respectively.The predominant concentrations of sulphydryl groups on the membrane are found at sites on the transmembrane proteins and, in particular, on the hexose transport protein. By influencing the nutritional status of the cells significant differences in activity between the normal and diseased state have been identified and these may have a role in the aetiology of rheumatoid arthritis by altering the response of cells to oxidative stress.

Oxidative Stress and the Use of Antioxidants for the Treatment of Rheumatoid Arthritis

“…It has been known for more than two decades that plasma or red blood cells taken from RA patients have significantly reduced free sulfhydryl levels [106,107] or elevated lipid oxidation by-products such as MDA [43]. For example, Miesel et al [16] reported that the plasma free sulfhydryl content was reduced by 45-75% in serum from RA patients versus healthy controls, whereas levels of XO were increased up to 50-fold.…”