FREE AMINO ACIDS OF BLOOD AND URINE 257 
McGILEs®®*, TEGELAERS AND TIDDENS®® STANDBURY AND MGGAULAY®’, HOOFT AND 
VERMASSEN®S, have described hyperaminoaciduria in patients with lipoidic nephrosis 
and also under some special conditions of treathment with protein and ACTH. 
C. Hyperaminoacidurta secondary to some other congenital metabolic disturbances 
In those cases, the aminoaciduria is of the common type, generalized and not specific to 
the etiologic factor of the metabolic disorder. It is found in the following conitions: 
1) Wilson's disease. Copper metabolism is primarily concerned. The aminoaciduria 
is secondary to a reabsorption defect and many amino acids are involved among 
which proline, citrulline and cystine deserve special mention. There is neither 
hyperlysinuria nor hypertaurinuria and the plasma levels are close to the lower 
limit of their normal distribution range. 
2) Galactosemia. It is accompanied by a generalized aminoaciduria resulting from 
an impairment of tubular reabsorption due to galactose accumulation in the tubular 
cells. As a secondary factor, some degree of hepatic insufficiency may complicate 
the picture by addition of a true “overflow” aminoaciduria to the renal one. In this 
case, all amino acids are hyperexcreted, including taurine and BAIBA. These 
troubles disappear when galactose is excluded from the diet. 
3) Levulosemia. It leads to a picture very close to that produced by galactosemia. 
4) Lowe syndrome. This syndrome is characterized by glaucoma, mental deficiency, 
thermoregulation unbalance and acidosis due to insufficient ammonia formation in 
the kidney. It is also associated with hyperaminoaciduria of the common type and 
the plasma amino acid levels are within normal limits. 
5) Tothe above categories of “renal” aminoaciduria may also be added the abnormal 
excretion found in progressive muscular dystrophy, in gargoylism, in some types 
of coproporphyrinurias and in infantile congenital cirrhosis. Unfortunately informa- 
tion on such disturbances as regard to amino acid excretion is still scarce and difficult 
therefore to interpret. 
D. Hyperaminoaciduria secondary to acquired metabolic disturbances 
In this group of conditions, the aminoaciduria may be either of the common gener- 
alized type, or of the specific type involving only a few amino acids. Different etiologic 
factors, by means of a common initial pathogenic process may result in the same 
urinary amino acid pattern. The conditions listed below are of a much more common 
occurrence than those which are genetically determined. 
t) Conditions having in common profound general disturbances, excessive cellular 
catabolism, associated or not to a nutrition deficiency and a negative nitrogen balance. 
The common feature shared by all those conditions is taurine or taurine and BAIBA 
hyperexcretion. Owing to adequate therapy the hyperexcretion is reversible, rapidly 
as regard to taurine, more slowly when BAIBA is concerned. RUBINI et al.*° and 
Fink et al.7® have shown that BAIBA metabolism is closely related to that of nucleic 
acids and particularly to that of thymine. Excessive tissue breakdown leads to 
BAIBA hyperexcretion, but its plasma level hardly rises to more than detectable 
traces since it has a clearance near that of inulin. Taurine hyperexcretion may be 
either a consequence of increased oxidation of sulfur amino acids or of abnormal 
References p. 261/262 
