A striking rise of serum guanidinosuccinic acid (s-GSA) in the critical period of CRF

It is reported that blood urea nitrogen (BUN) rises up logarithmically with advancement of renal dysfunction, and serum guanidinosuccinic acid (s-GSA) rises in parallel with BUN, but there is no mention about the rising pattern of s-GSA during the course of CRF. In order to investigate the significance a rising pattern of s-GSA in relation to the progression of renal damage, we measured serum creatinine (s-Cr), BUN, and s-GSA in 79 patients with CRF due to chronic nephritis or polycystic kidney disease recieving conservative therapy. The paramater of renal function, we use the reciprocal of s-Cr(1/Cr). The logBUN was significantly in negative proportion to 1/Cr (logBUN=-1.33×1/Cr+2.21 r=-0.845 p