Effects of creatinine, creatol and methylguanidine on renal function

Creatinine (Cr), creatol or methylguanidine (MG) was administered intraperitoneally to normal rats, and several renal function parameters were examined in an attempt to clarify the pathology under the various conditions. The glomerular filtration rate, renal plasma flow and renal blood flow after administration of Cr remained virtually unchanged when compared to those in the control group. In contrast, administration of creatol induced a significant decrease in these renal functions. Further decreases in the renal functions were observed in the rats given MG. However, the level of serum MG was extraordinarily high in the rats given creatol or MG. The toxic effects are discussed on the basis of the above results.