Zur Pathogenese des Schwachsinns bei Phenylketonurie

Linneweh, F.; Ehrlich, M.

doi:10.1007/bf01477102

Cited by 35 publications

(8 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In general, the amino acid pattern in plasma was very similar to the one reported by Linneweh and Ehrlich (1962) and Efron and colleagues (1969) in PKU children ( Figure 2). Table 1 and from Linneweh and Ehrlich (1962) and Efron and colleagues (1969) are shown here as per cent of control. Non-essential amino acids were not included in the statistical calculations in Linneweh and Ehrlich.…”

Section: Resultssupporting

confidence: 87%

“…It may be relevant that under our relatively acute experimental as well as more prolonged (Christensen, 1987b) conditions, we have observed a pattern of plasma amino acids very similar to the one reported in PKU children (Figure 2; Linneweh and Ehrlich, 1962;Efron et al, 1969). As far as we are aware, the plasma amino acid pattern characteristic of PKU had not previously been reproduced in animals (Dolan and Golin, 1967;Kaufman, 1977).…”

Section: C 4 Gsupporting

confidence: 72%

“…It may also be relevant that Efron and colleagues (1969) found an enhanced decrease of the amino acids affected in plasma in two of their PKU patients after an intravenous infusion of Phe. The differences were, however, also statistically significant when the patients were in their chronic condition, as was also apparently the case in the patients of Linneweh and Ehrlich (1962). On the other hand, Snyderman and colleagues (1981), in measuring several amino acids in fasting newborn PKU patients, found that only Thr showed a statistically significant decrease in the plasma, although Ala and also Arg were decreased along with Thr in the cerebrospinal fluid.…”

Section: C 4 Gmentioning

confidence: 86%

“…The plasma concentrations of several dipolar amino acids, the large ones less generally affected, decrease in plasma in PKU patients (Linneweh and Ehrlich, 1962;Efron et al, 1969). The mechanism of this change is not known; malnutrition and loss in the urine have been excluded as possible explanations; decreased intestinal absorption or loss into the gut lumen is unlikely (Efron et al, 1969).…”

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Evidence for inhibition of exodus of small neutral amino acids from non‐brain tissues in hyperphenylalaninaemic rats

Céspedes¹,

Thoene²,

Lowler³

et al. 1988

J of Inher Metab Disea

View full text Add to dashboard Cite

The mechanism of the depletion of several plasma amino acids in PKU has remained unexplained. In the present study, a statistically significant decrease in the plasma concentration of several amino acids was observed 2 h after the intraperitoneal injection of Phe to weanling rats. The pattern was very similar to the one observed in PKU patients. Statistically significant increases in the distribution ratios liver/plasma and, mainly, muscle/plasma ratios accompanied in most of the cases the corresponding decreases in plasma concentrations. Equimolar injection under the same conditions of the non-insulinogenic transport system L analogue, the a(+/-) isomer of the 2-aminonorbornane-2-carboxylic acid, produced, in a parallel effect to Phe, statistically significant increases in the distribution ratios of Ala and Gly, and probably of Pro in muscle, as well as of Ala in liver. These results seem to indicate that the high intracellular Phe attained inhibits the exodus of small neutral amino acids through system L, causing their depletion in plasma and ultimately in the brain. This effect may be additive to the inhibition by Phe of the entry of bulky neutral amino acids at the level of the blood-brain barrier. Further study is needed to assess the relevance of these effects to PKU.

show abstract

Section: Resultssupporting

confidence: 87%

Section: C 4 Gsupporting

confidence: 72%

Section: C 4 Gmentioning

confidence: 86%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Evidence for inhibition of exodus of small neutral amino acids from non‐brain tissues in hyperphenylalaninaemic rats

Céspedes¹,

Thoene²,

Lowler³

et al. 1988

J of Inher Metab Disea

View full text Add to dashboard Cite

show abstract

“…Symptomatik mit anderen erblichen Aminosäure-Stoffwechselstörungen -z.B. der Phenylketonurie -auch bei der temporären Hypertyrosinämie die durch kompetitive Hemmung des Transportes essentieller Aminosäuren nachgewiesenen Konzentrationsungleichgewichte (Aminosäuren-Imbalance) in ihrer schädigenden Auswirkung auf die Proteinsynthese in einem kritischen Stadium der Hirnentwicklung diskutiert (5,6,7). Diese Hypothese scheint auch durch experimentelle Befunde an der Ratte gestützt zu werden (8), die jedoch von anderen Autoren nicht bestätigt werden konnten (9,10).…”

unclassified

Untersuchungen zur Frage einer Aminosäuren-Imbalance unter den Bedingungen einer experimentellen Hypertyrosinämie bei der Ratte

Schaumlöffel¹,

Fekete²

1974

Clinical Chemistry and Laboratory Medicine

View full text Add to dashboard Cite

Tlie question of amino acid imbalance under the conditions of experimental hypertyrosinaemia in the ratC] L-leucine, the animals were killed, and the concentration of free amino acids and the utilization of the labelled pool for protein synthesis were determined in the serum, brain, liver, lung, spleen and kidneys. In the serum, brain and liver, the concentrations of free amino acids were determined by column Chromatography. Owing to a rapid degradation to metabolic end products, the high dose of tyiosine did not result in a hypertyrosinaemia, i. e., there was neither an inhibition of the transport of essential amino acids into the cells, nor an interference in protein synthesis. The relatively high tissue concentration of tyrosine metabolites had no recognizable negative effect on tissue metabolism.

show abstract

Atypical Phenylketonuria With Borderline or Normal Intelligence

Hsia¹,

O'Flynn²,

Berman³

1968

Arch Pediatr Adolesc Med

View full text Add to dashboard Cite

In the past, it was believed that nearly all patients afflicted with this disorder were mentally retarded. In a survey covering all published cases, Jervis 1 found that only three out of 330 phenylketonuric children (0.9%) had an intelligence quotient above 70. In 1960, Knox2 reported that there were 20 known untreated patients with phenylketonuria having "high grade" intelligence. Of these, eight patients had IQs between 60 and 69; six patients had IQs between 70 and 79; three patients had IQs between 80 and 89; and three patients had IQs over 90. More recently, Knox3 has expressed the view that no single factor can account for the relatively mild intellectual defect in these "atypical" phenylketonuric children. He believes that some of these have a biochemical defect which is often as severe as in the usual patient with phenylketonuria. But there appears to be a second group of patients with lower plasma phenylalanine levels; a few also have mildly affected relatives.The widespread screening for phenyl¬ ketonuria among newborn infants has led to the recognition that not all instances of hyperphenylalanemia are caused by

show abstract

Zur Pathogenese des Schwachsinns bei Phenylketonurie

Cited by 35 publications

References 4 publications

Evidence for inhibition of exodus of small neutral amino acids from non‐brain tissues in hyperphenylalaninaemic rats

Evidence for inhibition of exodus of small neutral amino acids from non‐brain tissues in hyperphenylalaninaemic rats

Untersuchungen zur Frage einer Aminosäuren-Imbalance unter den Bedingungen einer experimentellen Hypertyrosinämie bei der Ratte

Atypical Phenylketonuria With Borderline or Normal Intelligence

Contact Info

Product

Resources

About