Hemoglobin and Plasma Protein Production

1947

Self Cite

It is crystal clear from the experiments tabulated below, in the accompanying Paper I, and elsewhere reported (3, 4) that the doubly depleted dog (anemic and hypoproteinemic) can use the growth mixture of ten essential amino acids to form large amounts of new blood proteins (hemoglobin and plasma protein), to maintain a positive balance between nitrogen intake and urinary nitrogen output, and to continue a healthy state for 3 to 6 weeks. Weight loss, regardless of the amounts of amino acids given by mouth or parenterally, ispractically always present and at times approaches or even exceeds the weight loss observed with zero protein intake.When the amino acid mixture is replaced by comparable amounts of good diet protein (estimated as nitrogen equivalents) we note an improved urinary nitrogen conservation, usually a decrease in new bIood proteins produced but a tendency to gain weight on a protein intake of 150 to 250 gin. protein per week. Given a suitable intake of a good food protein plus the basal protein-free diet, the dog will remain in a satisfactory state of double depletion for months with no weight loss and a liberal output of new blood proteins. Evidently the whole protein (egg, liver, meat, casein, lactalbumin) may contain something not found in the amino acid mixtures, as all other factors appear to be alike in the experiments. This missing substance or compound we assume is responsible for the increased conservation of nitrogen and weight gain. It appears probable that this type of experiment (double depletion) with anemia and hypoproteinemia places a severe strain on the animal--more than simple weight maintenance and of a different order than growth requirements. This severe test of double depletion may magnify the deficiencies of any amino acid mixtures or digests when compared with the best food proteins. The pattern of blood protein production in certain experiments is modified by these same factors (amino acids contrasting with food protein). Whatever this unknown substance may be, it is important to learn more about it. Eventually it should be of great value in the construction of amino acid mixtures and digests suitable for long continued optimum parenteral feeding.

mentioning

confidence: 78%

Anemia and Hypoproteinemia

Miller

1947

Self Cite

“…This diet with accompanying weight loss cannot be continued indefinitely; recovery periods are therefore interspersed in the experimental program. General technical procedures concerning the animals and experiments proper have been described previously (6)(7)(8).…”

Section: Methodsmentioning

confidence: 99%

Plasma Protein and Hemoglobin Production

Miller

1947

Self Cite

Given healthy dogs fed abundant iron and protein-free or low protein diets with sustained anemia and hypoproteinemia, we can study the capacity of these animals to produce simultaneously new hemoglobin and plasma protein. Reserve stores of blood protein-building materials are measurably depleted and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for weeks or months depending upon the intake of food proteins or amino acid mixtures. These dogs are very susceptible to infection and various poisons. Dogs tire of these diets and loss of appetite terminates many experiments. Under these conditions (double depletion) standard growth mixtures of essential amino acids are tested to show the response in blood protein output and urinary nitrogen balance. As a part of each tabulated experiment one of the essential amino acids is deleted from the complete growth mixture to compare such response with that of the whole mixture. Methionine, threonine, phenylalanine, and tryptophane when singly eliminated from the complete amino acid mixture do effect a sharp rise in urinary nitrogen. This loss of urinary nitrogen is corrected when the individual amino acid is replaced in the mixture. Histidine, lysine, and valine have a moderate influence upon urinary nitrogen balance toward nitrogen conservation. Leucine, isoleucine, and arginine have minimal or no effect upon urinary nitrogen balance when these individual amino acids are deleted from the complete growth mixture of amino acids during 3 to 4 week periods. Tryptophane and to a less extent phenylalanine and threonine when returned to the amino acid mixture are associated with a conspicuous preponderance of plasma protein output over the hemoglobin output (Table 4). Arginine, lysine, and histidine when returned to the amino acid mixture are associated with a large preponderance of hemoglobin output. Various amino acid mixtures under these conditions may give a positive urinary nitrogen balance and a liberal output of blood proteins but there is always weight loss, however we may choose to explain this loss. These experiments touch on the complex problems of parenteral nutrition, experimental and clinical.

“…(Received for publication, December 2, 1948) For several years this laboratory has contributed to the study of simultaneous anemia and hypoproteinemia (double depletion in dogs). The production of new hemoglobin and plasma protein in these animals can be controlled by the protein intake (1)(2)(3). The doubly depleted dogs (anemic and hypoproteinemic) give an opportunity to study the production response to various digests, pure food proteins, and amino acid mixtures.…”

mentioning

confidence: 99%

Dietary Effects on Anemia Plus Hypoproteinemia in Dogs

1949

Self Cite

Doubly depleted dogs (anemic and hypoproteinemic) respond favorably to all the diet proteins used in the above experiments. Egg products (whole egg, albumin, or egg yolk) are well utilized by these dogs. Egg proteins favor the production of plasma protein and in some experiments the output of plasma protein is actually more than the output of hemoglobin. In contrast fresh beef muscle favors hemoglobin production—the output being 3 or 4 times that of plasma protein. The processed egg albumin fed in Table 4 was not well utilized and there was weight loss. Beef muscle (fresh or processed) gives a total blood protein output about twice that with egg feeding and there is a striking preponderance of hemoglobin output. Beef heart and salmon muscle show a pattern much like beef muscle. The total blood protein output is below that due to beef muscle.