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Urinary Concentrations of Total Protein, β2‐Microglobulin and Amino Acids in Healthy Newborn Infants
Author(s) -
Suzuki Yoshifumi,
Shimao Satoshi,
Konishi Toru
Publication year - 1981
Publication title -
pediatrics international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.49
H-Index - 63
eISSN - 1442-200X
pISSN - 1328-8067
DOI - 10.1111/j.1442-200x.1981.tb01644.x
Subject(s) - medicine , creatinine , beta 2 microglobulin , proteinuria , urine , urinary system , renal function , albumin , endocrinology , amino acid , kidney , biochemistry , chemistry
The urinary concentrations of total protein, low molecular weight proteins, amylase, and total amino acid were determined from 104 healthy newborn infants during the first 15 days of life. The urine samples were collected after spontaneous voiding every two hours. Neonatal proteinuria was found in 70 per cent of 2 day old infants. No infant older than 8 days showed proteinuria. The ratio of mean value of β2‐microglobulin to creatinine was highest on the 5th day of life, followed by a rapid decrease after the 6th day. On the 15th day the β2‐microglobulin concentration was still high. The mean ratios of total amino acid to creatinine and amylase to creatinine increased gradually during the first 9 days of life, and then decreased rapidly after the 10th day. The highest urinary concentration of other low molecular weight proteins was found between the 7th and 8th day. On the other hand, the lowest concentration of albumin was found between the 7th and 8th day. These findings suggest that the proximal tubular function is immature in the newborn period. (Acta Paediatr Jpn 23(3):326–332 1981)