Creatol, a Creatinine Metabolite, as a Useful Determinant of Renal Function

Abstract

Analysis of creatoi (CTL, 5-hydroxycreatinine), an oxidative creatinine (Cr) metabolite, in serum and urine of human subjects has indicated that CTL is a useful determinant of renal function. The existence itself of serum CTL (s-CTL) could be a diagnostic sign for chronic renal failure (CRF): in all normal subjects, s-CTL was undetectable, but s-CTL was detectable in sera of all patients with CRF (s-Cr: > 2.0 mg/dl). And the s-CTL values increased in proportion to the severity of CRF in such patients. Furthermore, the molar ratio (CTL/Cr) in both urine and serum increased significantly in proportion to the severity of CRF. Our results indicated not only hyperproduction of CTL but also higher oxygen stress in patients according to the progression of CRF. The diagnostic importance of the CTL value and the CTL/Cr ratio are discussed.

Daily hydroxyl radical scavenging capacity of mammals

“…Daily severity of CKD. Both CTL and MG in serum and urine were initially indicated to be markers for CRF (1,(12)(13)(14). However, both were later recognized to be markers of •OH (1-3,5-9).…”

“…Although we can detect in vitro creatones A and B as intermediates from CTL to MG (11), we do not introduce them herein, because they are not detectable in vivo. CTL and MG in serum and urine have been recognized as in vivo markers of •OH (1-3,5-9), although they were initially known as markers for chronic renal failure (CRF) (12)(13)(14). We can estimate their daily scavenging capacity for •OH using the urinary Crn-related metabolites of CTL, MG, and DMC.…”

Creatinine and HMH (5-hydroxy-1-methylhydantoin, NZ-419) as intrinsic hydroxyl radical scavengers

“…The molar ratio (CTL + MG)/Crn in serum and urine is correlated well with sCrn values (1,50,58). It was thought that sMG increases in proportion to sCrn according to a simple equation, but we have shown that the correlation followed a quadric equation (1,50,58).…”

Urinary Excretion of Creatol, an In Vivo Biomarker of Hydroxyl Radical, in Patients with Chronic Renal Failure

“…Thus, the serum CTL level and the CTL/Cr molar ratio are also reported to be good biomarkers of hydroxyl radicals. [10][11][12][13] Theoretically, the molar sum, CTL+MG, and its ratio to Cr, (CTL+MG)/Cr, may be the best indices for the precise hydroxyl radical level in vivo.…”