[Platelet aggregation in chronic renal failure--whole blood aggregation and effect of guanidino compounds]

Studies were performed on the platelet aggregation (PA) in patients with chronic renal failure (CRF) and normal subjects (NS). The PA was investigated in the whole blood by the electrical impedance method. The concentrations of plasma (P-) and erythrocyte (E-) guanidinosuccinic acid (GSA) and methylguanidine (MG) in uremic patients with CRF were determined by high performance liquid chromatography. GSA and MG are guanidino compounds (GC) and have been widely shown to act as uremic toxins. The effects of GSA and/or MG on the PA of NS were also investigated. The results showed that the PA of conservative therapy patients with CRF was significantly lower than that of NS, while the PA of hemodialysis (HD) patients was improved. The PA of continuous ambulatory peritoneal dialysis (CAPD) patients was rather high and the possibility of sugar and lipid metabolic disorders was suggested as the cause. The concentrations of P- and E-GSA and MG in uremic patients with CRF were increased. But there were no significant correlations between the PA and the concentrations of GSA and MG. In vitro, GSA and/or MG at a high concentration exerted a significant inhibitory effect, while at a low concentration they showed a lesser inhibitory effect on the PA. In conclusion, based on their inhibition of the PA in patients with CRF, the dialyzable materials, GSA and MG, are considered to represent active uremic toxins.