Studies on Guanidine Compounds in Uremia Reevaluation of Serum GSA in Relation to Acute Symptoms of Uremia

We have studied serum levels of guanidinosuccinic acid (GSA) and methylguanidine (MG), giving special attention toward longitudinal changes in the course of renal failure in relation to acute symp-toms associated with uremia. Serum GSA and MG levels were measured by the chromatographic methods according to Grof et al, and Stein. & Micklus, respectively. Hemodialysis was initiated with conventional Cuprophan dialyser in either condition : BUN avove 80 mg/d1, creatinine above 8.0mg/dl or displaying acute symptoms associa-ted with uremia.(1) In the stable state of renal failure, serum GSA or MG changed paralell with BUN or creatinine, respectively. The ratio of GSA to BUN (GSA/BUN x 100) was usually between 0.5 and 0.6.(2) At the start of hemodialysis, however, 16 patients displaying acute symptoms, such as CNS distur-bance, slow wave in EEG, uremic lung, pericarditis and severe vomiting, showed marked increase in GSA Level disproportionally to the increase in BUN, while the other 10 asymptomatic patients showed a similar level of GSA and GSA BUN as in the stable state.(3) Fourteen of 16 patients with acute uremic symptoms showed GSA/BUN above 1.0% at the start of hemodialysis. On the other hand, all of 10 asymptomatic patients showed GSA/BUN below 1.0.(4) Four patients of the symptomatic group, whose acute uremic symptoms continued despite intensive hemodialysis therapy, died within one month after the start of hemodialysis. In three of these four pat-ients, GSA/BUN remained above 1.0/ throughout the course These results indicate that serum levels of GSAA in relation to BUN, especially, the ratio of. GSA to BUN, might be a promising parameter for the managenent as well as the diciding the time to start dialysis therapy of patients with renal failure.