Studies on plasma amino acids in East African adults in relation to endomyocardial fibrosis

Abstract

1. An examination has been made of the plasma amino acids of adult Uganda Africans at risk to endomyocardial fibrosis compared with people from areas where the disorder is rare. The amino acid profile, both free and in the protein of the main staples, has also been examined.2. Plasma tryptophan was found to be low in adults at risk and intermediate in Africans receiving a higher protein intake, as compared with Europeans whose protein intake might include more than 40 % as animal products.3. Leucine and valine were also low in the plasma of adult Africans at risk.4. The non-essential amino acids alanine and glycine were increased in the adult Africans at risk.5. The similarity of these changes with the changes seen in kwashiorkor by other workers suggests that adherence to limited vegetable diets may introduce a chronic stress with regard to certain essential amino acids.6. Studies on the vegetable staples used by Africans established that they are particularly poor in tryptophan and such Africans are probably dependent on other sources for their trypto-phan. None of the staples was a rich source of leucine. Plantain contained relatively large amounts of histidine, and cassava of arginine.7. A comparative study of muscle protein suggests that the composition is similar regardless of diet and species. Leucine is quantitatively one of the most important amino acids in the muscle profile.8.The above findings are discussed in the context of the requirements for heart muscle and the high incidence of cardiomyopathies within such African communities.

Childhood acquired heart diseases in Jos, north central Nigeria

“…Reasons adduced for this apparent change include general improvements in nutrition and socioeconomic conditions. Deficiencies of the amino acids leucine, valine, and tryptophan had earlier been implicated in the aeitology of EMF in adults in East Africa 40. Also, basic sanitation has improved, while better education including health education may have effected some behavioral changes that might have led to a reduction in the incidence of parasitic infections suggested in the past to be associated with EMF 41…”

Comparison of the fatty acid component in structural lipids from dolphins, zebra and giraffe: possible evolutionary implications

“…Studies on the evolutionary variation of amino acid sequences in proteins have shown that it is largely confined to minor alterations of one or, at the most, a few codons (Nolan & Margolaish, 1968), and the variability in terms of the component proportions of essential amino acids has been found to be small (Crawford, Gale, Somers & Hansen, 1970). Cell structural lipids, with the exception of the brain, exhibit wide variations in the essential fatty acid (EFA) component of cell structural lipids in such a manner that a contribution to evolutionary differences has been suggested (Crawford & Sinclair, 1972;Crawford, Casperd & Sinclair, 1976).…”

Dietary alterations in polyunsaturated fatty acids in guinea-pig brain, liver and muscle

“…It is also known that surface-active agents used in the preparation of emulsions influence the activity (Fielding, 1970a;Doizaki & Zieve, 1968) Human cardiomyopathies are more commonly found in low socio-economic groups in parts of the world where the incidence of protein malnutrition is high (Shaper & Coles, 1965;Crawford, Gale, Somers & Hansen, 1970). The response of the endocardium and myocardium to low-protein diets has been demonstrated experimentally (Spatz, 1965(Spatz, , 1969McKinney & Crawford, 1965;Reid & Berjack, 1966).…”