Abstract
To obtain more sensitive and more stable method for determination of methylguanidine (MG), the Sakaguchi reaction was carried out in an ice bath by adding of urea and thymine to the reagents. MG concentration in the human blood cells of healthy and uremic subjects, and the tissue concentration of MG in the blood cells, liver, muscle, colon, kidney and brain in the uremic rats made by the Platt method and normal rats were determined respectively. In the blood cells of uremic patients, MG was concentrated about three fold comparing to the serum level. In addition, except for brain, all tissue concentrations of MG in the uremic rats were three to four times higher than that of serum. These tissue concentrations seem to be sufficient for MG to exert as a uremic toxin. In the uremic rats fed with protein free diet, the production rate of MG was reduced. On the other hand, in the uremic rats fed with high protein diet the production rate of MG was increased. Although the serum creatinine concentration was not changed by these dietary conditions. These results implied that the metabolic production of MG has a close relation to the protein metabolism in uremia
