Methylguanidine (MG) has been demonstrated to be elevated in serum of uremic patients and its retention, per unit of serum creatinine concentration, to be higher in the anuric patients than in those with urine output exceeding 400 ml/day. The metabolic production of MG has been found to be increased in renal failure and correlated with the serum creatinine concentration, and its renal tubular excretion to be also elevated. In ten dogs submitted to ligature of the ureters, higher concentrations of MG were found in liver, muscle, and sciatic nerve as compared to serum and brain. Decreased body weight, anemia, increased serum triglycerides, and neurological and gastrointestinal disturbances were noted in dogs chronically intoxicated with MG, and at serum levels of MG comparable to those of severely uremic patients.
Giovannetti S, Balestri PL, Barsotti G. Methylguanidine in Uremia. Arch Intern Med. 1973;131(5):709-713. doi:10.1001/archinte.1973.00320110093014