Kwashiorkor, amino acids

All 20 of the amino acids present in proteins are essential for health. While comparatively rare in the Western world, amino acid deficiency states are endemic in certain regions of West Africa where the diet relies heavily on grains that are poor sources of amino acids such as tryptophan and lysine. These disorders include kwashiorkor, which results when a child is weaned onto a starchy diet poor in protein and marasmus, in which both caloric intake and specific amino acids are deficient. 

The ratio of essential to non-essential amino acids is high in kwashiorkor but normal in marasmus. The cause of this may be low activities of the enzymes for metabolising the essential amino acids. These are required for any protein synthesis that must take place even in kwashiorkor. 

In our laboratory, nine cases of colored children from Central Africa, suffering from typical kwashiorkor, have been examined, using Moore and Stein s 1954 method. Abnormal amino aciduria was observed in most cases, both before and in the early stage of protein treatment, by comparison with normal subjects of the same region. Taurine and (3-amino-isobutyric acid were abundantly excreted (Fig. 6). Under protein treatment the drop in amino acid output is a most striking feature of the... 

Roediger, W.E.W. New views on the pathogenesis of kwashiorkor methionine and other amino acids. J. Pediatr. Gastroenterol. Nutr. 1995 21 130-136... 

Kwashiorkor is thought to involve "confused hormones," An adequate supply of carbohydrates, in the form of starchy roots or sugar cane, can result in maintenance of high levels of plasma insulin, which can prevent the net proteolvsis that otherwise w ould supply the liver and immune system with amino acids. The mechanism by which insulin controls muscle turnover is not well understood however, in marasmus the body s stores of fat and muscle are broken doiwn and mobilized in a more coordinated fashion, resulting in a relatively gradual decline in overall health. 

Kwashiorkor Decrease in essential amino acids and tyrosine more than nonessential Ratio of essential to unessential amino acids helpful in diagnosis even with subclinical levels of protein deficiency abnormal phenylalanine tolerance test... 

Kwashiorkor, a common problem of children in Third World countries, is caused by a deficiency of protein in a diet that is adequate in calories. Children with kwashiorkor suffer from muscle wasting and a decreased concentration of plasma proteins, particularly albumin. The result is an increase in interstitial fluid that causes edema and a distended abdomen that make the children appear "plump" (see Chapter 44). The muscle wasting is caused by the lack of essential amino acids in the diet existing proteins must be broken down to produce these amino acids for new protein synthesis. 

Extensive amino-aciduria was observed in both normal Infants and infants with kwashiorkor when fed a diet that contained D-amino acids (114). It appeared that the D-isomers present were incompletely utilized and this accounted for most of the excretion. 

An isolated report describes an elderly woman treated with aminophylline by intravenous infusion who had a marked fall in her serum theophylline levels (from 16.3 to 6.3 mg/L) when the amino acid concentration of her parenteral nutrition regimen was increased from 4.25 to 7%. " A study in 7 patients with malnutrition (marasmus-kwashiorkor) found only a small, probably clinically irrelevant increase in the elimination of a single intravenous dose of theophylline when they were fed intravenously. ... 

The condition of extreme protein deficiency is called kwashiorkor. The name comes from an African dialect and translates as "the evil spirit that infects the first child when the second one is born." Kwashiorkor begins when the earlier child is no longer breast-fed and is switched to a carbohydrate-based diet. On this carbohydrate-based diet the older child no longer receives the necessary amino acids. If nutrition is improved before the condition has progressed too far. health can be restored. 

The distribution of amino acids in the blood and urine of patients with kwashiorkor is modified. The total amino acid content of the serum is decreased. The reduction affects some amino acids more than others. For example, the serum is low in arginine, leucine, and threonine, but has a normal content of phenylalanine and tyrosine. The decrease in the amino acid content of the plasma varies considerably with the individual. Mexican authors have claimed that the total amino acid content of the plasma may drop to half of the normal values. 

In contrast to what happens in plasma, the amino acid content of urine is increased. Increased amounts of j8-aminoisobutyric acid, ethylalanine, isoglutaric acid, taurine, and histidine have been reported. The increase results from reabsorption failure of the kidney, either because of renal damage or because the amount of amino acid in the glomerular filtrate exceeds tubular thresholds. Neither of these interpretations is quite satisfactory since there is usually no renal damage in kwashiorkor, and the amino acid level is reduced in plasma. 

Ethylalanine excretion can be reversed by administering methionine therefore, increased excretion of ethylalanine appears to result from the lack of methyl groups. The total urinary nitrogen content is increased in patients with kwashiorkor. This results from increased levels of urinary amino acids. But the increase in urinary amino acid cannot explain the overall increase in urinary nitrogen, and it has been suggested that part of this increase results from increased purine excretion. The structure of the excreted purine is not known. 

The changes in hair texture and color in patients with kwashiorkor remain unexplained. A deficiency in sulfur amino acid was postulated as the cause of changes in the hair. However, when cysteine content of hair of affected patients was compared with that of normal hair, contradictory results were obtained. Some investigators find that the cysteine content is decreased in kwashiorkor others find no changes. Another possibility is that the deficiency responsible for the hair changes in kwashiorkor is similar to that... 

The effect of a diet free of one of the essential amino acids has been studied in rats. When the animals are simply presented with a diet devoid of one of the amino acids, the rats regulate their food intake accordingly by reducing consumption. If the diet devoid of one of the essential amino acids (except arginine) is force-fed, the rats develop a malnutrition syndrome that has sometimes been compared to that observed in human kwashiorkor. 

In kwashiorkor there is less breakdown of protein and release of amino acids from muscle than in marasmus since provision of adequate energy in the diet reduces the adrenal cortical response to starvation and, consequently, the flow of amino acids from muscle to viscera. The release of amino acids from muscle is, therefore, not sufficient to meet the needs of the internal organs. 

Kwashiorkor— The specific features which distinguish this disorder from marasmus are (1) a significantly subnormal albumin concentration in plasma, (2) swollen parotid glands (just under and in front of the ears), (3) a depressed ratio of essential to nonessential amino acids in the blood plasma, (4) fatty liver (which often may be palpated, and (5) a moderate deficit in weight for height and age (the weight is usually 80% or more of normal). 

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