With the aid of ion exchange column chromatography we determined quantitatively the free amino acids in eccrine, thermal sweat. Sweat was collected (a) from the face of 27 healthy men and 26 healthy women (b) from the face, chest, armpits, shoulders, back, upper part of the abdomen, hypogastrium, forearms and thighs of the same individual and (c) from the face of the same individual at different times. Sweat was deproteinised by adding an equal volume of 5% sulphosalicylic acid. 1. The results showed not only a constant, qualitative amino acid pattern in sweat, but also a relative constancy among the individual amino acids. 2. The concentrations of the free amino acids in sweat showed significant, individual variations. Particularly high excretion rates were observed in the following amino acids: alanine, glycine, citrulline, histidine, ornithine, threonine and serine. 3. As compared to men, women had an increased excretion of all the examined amino acids in sweat from the face, except for cystine. Statistically significant higher excretion was seen within this sex-specific comparison for the following amino acids: alanine, citrulline, glycine, histidine, isoleucine, serine, taurine, threonine, tyrosine and valine. 4. Essential amino acids such as isoleucine, leucine, lysine, methionine, phenylalanine and valine and also cystine were always excreted only in small amounts. 5. Significant differences were also observed in the total amino acid excretion and in the individual amino acid excretions in sweat obtained from different parts of the body of the same person. 6. The amino acid concentrations determined in the sweat from the face of the same individual at different times showed a relative constancy as compared to the large differences of the amino acid concentrations determined in the sweat from the face of different individuals.

Endogenous renal transport of free amino acids was determined in 12 infants, between the ages of 16 days and 4 months, and in 12 children, between 2 and 13 years of age. Values of the serum concentrations, urinary excretion, renal clearance rates, net tubular reabsorption, and percentage tubular reabsorption of 17 amino acids were obtained by short-term clearance studies, including the determination of the glomerular filtration rate by inulin. The amino acids were determined by ion exchange chromatography. A comparison of the values of infants and children revealed a specific feature of the kidney function in infancy. The urinary excretion of threonine, serine, proline, glycine, and alanine and the clearance rates of serine, proline, glycine, and alanine were significantly higher in infancy. The percentage tubular reabsorption of all amino acids was characteristically lower in infancy than in childhood, while the values of the net tubular reabsorption related to the glomerular filtration rate (TAA/CIn) were equal in both groups. These findings are thought to be due to a greater degree of heterogeneity of nephrons with increased glomerulotubular imbalance during the period of postnatal kidney development.

Zusammenfassung Bei 20 gesunden Männern, 20 männlichen Kaninchen, 20 männlichen Meerschweinchen und 20 Ebern wurden die freien Aminosäuren im Serum des Nüchternbluts quantitativ bestimmt. Das Serum wurde mit 5% Sulfosalicylsäure enteiweißt; die Auftrennung der Aminosäuren erfolgte durch Chromatographic an Ionenaustauschersäulen. Ergebnisse: Im Vergleich mit den Männern ist im Serum der männlichen Kaninchen die Konzentration von Alanin, Arginin, Glycin, Histidin, Isoleucin, Leucin, Lysin, Methionin, Ornithin, Phenylalanin, Prolin, Serin, Threonin, Tyrosin und Valin statistisch signifikant höher. Im Vergleich mit den Männern ist im Serum der männlichen Meerschweinchen die Konzentration von Alanin, Lysin und Tyrosin statistisch signifikant niedriger und die Konzentration von Arginin, Citrullin, Cystin, Glycin, Isoleucin, Methionin, Ornithin, Phenylalanin und Serin statistisch signifikant höher. Im Vergleich mit den Männern ist im Serum der Eber die Konzentration von Alanin, Arginin, Citrullin, Glycin, Isoleucin, Leucin, Ornithin, Phenylalanin und Valin statistisch signifikant höher. Der Vergleich der Aminosäure‐Konzentrationen, die im Serum der Kaninchen, Meerschweinchen und Schweine bestimmt wurden, untereinander, ergab eine Vielzahl statistisch signifikanter Unterschiede.

With the permission of their parents 24 newborn babies of varying weights and gestational ages have been studied with respect to their urinary excretion of calcium and phosphorus. Timed specimens of urine were collected as continuously as possible during the first 3 days and on the 7th day of life; venous specimens of blood were also obtained on each of these days. Calcium, phosphorus, sodium and creatinine measurements were performed on these specimens. It was found that both sodium and calcium excretion followed a similar course with high lwels of excretion soon after birth falling during the first 3 days and rising by the end of the first week. There were no statistically significant differences between groups of babies classed as pre-term, small for dates or mature. Serum calcium lwels fell during this week while phosphorus lwels rose. Urinary phosphorus excretion was low soon after birth but rose rapidly until by the end of the week phosphorus excretion seemed considerably to exceed phosphorus filtration. Assuming that creatinine handling by the kidney of the newborn is similar to that of older infants and that creatinine clearance'represents an approximation to glomerular filtration, these infants (fed on artificial phosphate rich diet)clearly ingest a gross excess of phosphate and seem able actually to secrete phosphorus into their renal tubules in an attempt to remove it.

Die direkte kolorimetrische Bestimmung von Ammonium 1 ) im Blut mit Hilfe der Indophenol-Reaktion ermöglicht durch ihre Einfachheit und Speziiität. die routinemäßige Durchführung im klinisch-chemischen Laboratorium. Die Untersuchung von 65 Säuglingen und Kindern bis zu 3 Jahren, bei denen für Leberschäden, Stoffwechselstörungen und endokrine Störungen klinisch und anamnestisch keine Anhaltspunkte bestanden, ergab als normale Ammonium-Konzentration 2 ) im Blut 121,9 ± 24,7 /ig/100 m/ Blut (Mittelwert aus 65 Doppelbestimmungen) mit Schwankungen zwischen 69 und 179 jwg/100 m/ Blut. Im Vergleich hierzu beträgt die Ammonium-Konzentration im Blut bei Kindern zwischen 3 und 14 Jahren 104,3 i 18,24 yWg/100 m/ Blut (Mittelwert aus 98 Doppelbestimmungen) mit Schwankungen zwischen 64 und 152/tg/100 m/ Blut. Bei Lebererkrankungen und Störungen im Harnstoffzyklus wurden höhere Ammonium-Konzentrationen im Blut gemessen. The ammonium concentration in tke venous blood of sucklings and childrenThe direct colorimetric determination of ammonium in blood with the aid of the indophenol reaction is simple and specific and suitable ' for routine measurements in the clinical chemical laboratory. The study of 65 sucklings and children up to age 3 years, in which there was no clinical or anamnestic evidence of liver damage, metabolic or endocrine disorders, gave normal values 2 ) of 121,9 ± 24,7 ^g ammonium/100 m/ blood (average of 65 duplicates) with a scatter of 69-179 /ig/100 m/ blood. By comparison, the blood of 3-14 year olds contained 104,3 ± 18,24 ^g/100 m/ blood (average of 98 duplicates) with a scatter of 64-152^g/100 m/ blood. Elevated concentrations of blood ammonium were found in liver disease and disorders of the urea cycle.Die bisher beschriebenen Verfahren der Ammoniumbestimmung im Blut können in zwei Gruppen zusammengefaßt werden. In der ersten Gruppe wird Ammonium zunächst nach einer der folgenden Methoden möglichst spezifisch und quantitativ isoliert durch: a) Destillation (5) b) Aeration (6, 7) c) Diffusion bzw. MikrodifTusion (8-30) d) Adsorption an einen Ionenaustauscher (31-38). Anschließend wird Ammonium selbst titrimetrisch oder photometrisch (nach Farbreaktion mit NESSLER'S Reagenz, reduziertem Ninhydrin, Phenol-Hypochlorit-Reagenz oder Hypobrorrut-Phenosaphranin-Reagenz) bestimmt. In der .zweiten Gruppe wird die AmmoniumKonzentration direkt im Gewebs-oder Blutextrakt nach Enteiweißung gemessen. Nach der Enteiweißung mit Trichloressigsäure, Perchlorsäure oder Natriumwolf ramat-Schwefelsäure erfolgt die Bestimmung mit Phenol-Hypochlorit-Reagenz (39-45, 51) oder auf enzymatischem Wege (44,(46)(47)(48)