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Application of the measurement of a novel tryptophan derivative for evaluation of renal function

Research Project

Project/Area Number 07672486
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Laboratory medicine
Research InstitutionHamamatsu University School of Medicine

Principal Investigator

YONEKAWA Osamu  Hamamatsu University School of Medicine Department of Laboratory Medicine Research associate, 医学部附属病院, 助手 (90158527)

Project Period (FY) 1995 – 1996
Project Status Completed (Fiscal Year 1996)
Budget Amount *help
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1996: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1995: ¥1,900,000 (Direct Cost: ¥1,900,000)
Keywordstryptophan derivative / renal function / creatinine / muscle volume / sugar / inulin clearance / 甲状腺ホルモン
Research Abstract

We have isolated a new tryptophan derivative from human urine. It was named as substance X (S.X). The compoundconsists of tryptophan and sugar residue and has molecular weight of 366.
In this study, we proposed that a measurement of S.X can be a new reliable marker of renal function.
Unlike creatinine (Cr.), serum levels and renal outputs of S.X are stable in healthy subjects from age 1 to age 60. S.X is elevated in serum of subjects older than 60 year old. This may indicate the decrease of renal function due to ageing. Relationships between S.X and Cr.and S.X clearance and Cr.clearance were excellent, Y=112.5+88.1x, r=0.842, y=0.23+0.59x, r=0.920, respectively. Unlike Cr.level, S.X level is not affected by the muscle volume. In this study, we used two parameters, Cr.output and body mass index, instead direct measurement of the muscle volume. In animal model, S.X clearance showed more close relationship to inulin clearance than Cr.clearance (Csx=0.028+0.945xCin, r=0.976 vs Ccr=-0.079+1.34xCin, r=0.959). Measurement of S.X is more reliable than that of Cr.in estimation of glomerular filtration rate.
Besides serum and urine, S.X was observed in anmiotic fluid and cerebral spinal fluid. S.X in amniotic fluid was increased with gestation period. S.X level in cerebral spinal fluid is higher than that in serum. This may suggest that S.X has biological role in central nervous system. The existence of S.X was confirmed in other species, like lamprey, chicken egg, mouse, rat, and dog. This means that S.X plays also some physiological role.

Report

(3 results)
  • 1996 Annual Research Report   Final Research Report Summary
  • 1995 Annual Research Report

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Published: 1995-04-01   Modified: 2016-04-21  

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