Blood Cell Amino Acid Research Articles

Breast and lung cancer are associated with a decrease in blood cell amino acid content

The description of different plasma amino acid profiles for specific types of cancer suggests that the metabolic alterations brought about by each type of tumor determine their own, distinctive profile of plasma amino acids. However, the blood cell pool represents an important percentage of the total amount of amino acids and has been reported to undergo significant changes in several physiological situations, thus raising the question of what effect a situation like cancer could have on amino acid blood compartmentation. We determined the levels of individual amino acids in blood, plasma and blood cell compartment of 14 lung cancer patients, 16 breast cancer patients and the corresponding healthy controls (n = 14 and 18, respectively). Cancer, a situation of increased amino acid demand, was accompanied by a decrease in the amino acid availability, of which the blood cell pool would be the main contributor. Thus, the fact that the blood cell pool reflects more intensely than plasma the changes in amino acid availability and undergoes changes according to the demand of amino acids, reinforces the important role of the cell pool in blood amino acid compartmentation and handling. The profiles of blood amino acids characteristic of different types of tumors that have been proposed by some authors could be extended to other compartments—in addition to the plasma—and even be more informative.

Blood amino acid compartmentation in men and women with different degrees of obesity

The role of blood cells in the interorgan transport of amino acids and the important size of such a pool has lead us to investigate the possibility that obesity causes alterations in amino acid blood compartmentation in humans and that such alterations show gender-linked differences given the special features of the obese state for each gender. We determined the blood levels of amino acids in whole blood and in the blood cell compartment of 42 men and 46 women. Subjects were classified according to their body mass index (BMI) into one of three groups: lean, overweight, or obese. Obesity was found to increase the levels of blood amino acids in both men and women, although not in the same way: In men, moderate overweight was accompanied by a significant increase of the amino acid blood levels, which were practically unchanged by a greater BMI; however, in women this same increase was observed only in the obese group. This effect is more marked in the cell compartment, where these alterations are actually reflected because plasma contribution values do not change as a whole. In conclusion, total blood and blood cell amino acids were altered in obesity, but in a different way, in both men and women depending on the degree of obesity. This profile of changes is seen to be particularly marked in the cellular pool, which contributes to enhancing the importance of this pool in the handling of amino acids.

Effect of diet and essential amino acids gavage on young rat amino acid metabolism enzymes

1. 1. The effects of a high-fat, high-energy diet and essential plus semi-essential amino acid gavage on pup rats have been studied (60–65 animals). 2. 2. The activities of alanine transaminase, adenylate deaminase, glutamine synthetase and serine dehydratase have been tested in liver and muscle. 3. 3. Plasma was used for the estimation of proteins, urea, amino acids, glucose, lactate, 3-hydroxy-butyrate and acetoacetate. 4. 4. Liver and muscle glutamine synthetase activities are increased by diet and gavage administered. Hepatic serine dehydratase is inhibited by a cafeteria diet but activated by amino acid gavage. Adenylate deaminase is inhibited by diet and gavage in the liver, but gavage does not affect this enzyme activity in muscle. Liver alanine transaminase is increased by the diet; in the muscle, cafeteria diet and amino acid gavage showed the highest values for this enzyme. 5. 5. In the plasma, the increase in lactate produced by the diet is inhibited by the amino acids provided. Cafeteria-fed pups showed lower urea levels and higher 3-hydroxybutyrate concentrations in the plasma. 6. 6. Intracellular glucose is diminished by cafeteria diet. In contrast, the blood cell amino acid concentration increases with diet and gavage supplied.

A significant pool of amino acids is adsorbed on blood cell membranes

It is well known that the amino acids in the blood are distributed between the plasma and inside the cells. This study was conducted to determine whether amino acids can be located adsorbed on blood cell membranes. The amino acid concentration in the deproteinized haemolysed blood was higher than that in the fraction of blood after removal of the blood cell membranes by centrifugation. These results showed that a pool of amino acids representing 21.1% of the whole blood cell amino acids was adsorbed on the blood cell membranes of adult Wistar rats. The non-polar amino acids showed high adsorption on the membrane, whereas out of the polar amino acid group, only the non-ionic amino acids did adsorb.

Sustained changes in blood alpha amino nitrogen compartmentation during recovery from cafeteria feeding in rats

We have previously reported that blood urea and blood cell amino acids levels are reduced in rats obese by feeding a palatable cafeteria diet. In order to distinguish whether these changes result from the altered diet, or from the obesity per se, we have studied cafeteria fed rats after returning to standard diet. As in previous studies, obesity induced by cafeteria feeding (for 90 days) was maintained when the cafeteria diet was removed and rats were fed standard diet only. After removal of the cafeteria diet, blood urea levels of 24 h starved obese rats were lower (23%) than those of starved control rats. Blood cell amino acid levels of obese were lower than control ones from day 50 onwards, during and after cafeteria feeding (21% lower on day 100 of life), and thus coincided with divergence of body weights; these differences were maintained despite removal of cafeteria diet. The effects of starvation on plasma amino acid levels were more marked in obese than control rats, during and after cafeteria feeding. Thus the effects on blood amino acids and urea levels in cafeteria diet induced obese rats are related to the obese status rather than to the diet composition.

The effects of cafeteria diet induced obesity on rat blood amino acid compartmentation

In female virgin Wistar rats, the effects of a cafeteria-diet induced obesity on blood amino acid levels and their distribution between plasma and blood cells have been studied in fed and 24-hour starved states. Cafeteria diet induced obesity provoked a decrease in total blood cell amino acid content, both in fed and starved situations when compared with controls. Whether is a causal factor for developing obesity due to imbalance in tissue amino acid supply for protein biosynthesis processes, or represents some signal related to hypothalamic control of feeding, or is a consequence of the obesity remains to be established.

Transport and hindlimb exchange of plasma and blood-cell amino acids in calves fed soy- or urea-based purified diets.

Plasma and blood-cell free amino acid concentrations and venoarterial differences across the hindlimbs via abdominal aorta and caudal vena cava cannulae were determined on Holstein steer calves (130 kg) fed purified diets containing soy protein or urea as the sole source of dietary N. Calves were fed 24 hourly feedings per day to promote "steady-state" metabolism. Trials lasted 30 d and consisted of four calves per treatment. Urea feeding resulted in reduced venous concentrations of plasma amino acids, namely, a 30% decrease in essential amino acids (P less than .05) and a 16% decrease in nonessential amino acids (P less than .10). Nonessential amino acid concentrations of blood cells were affected little in urea-fed calves; however, blood-cell essential amino acid concentrations were depressed due to significant decreases in threonine, valine, methionine, isoleucine and phenylalanine. A net negative concentration difference across the hindlimbs for plasma free amino acids was noted for soy-fed calves. Urea feeding resulted in a small positive amino acid concentration difference. The branched-chain amino acids (BCAA) changed (P less than .01) from a large negative concentration difference in soy-fed calves to essentially a zero difference in calves fed urea. Blood-cell total amino acid change across hindlimbs showed no treatment differences, although BCAA changed from large outputs from the blood cells in soy-fed calves to essentially zero change in urea-fed calves.

Amino acid compartmentation in chick blood during the peri-hatching period

1. 1. Individual amino acid levels and compartmentation in chick blood were measured on day 20 of incubation, at hatching (day 0), or after 1 or 5 days of free life, and compared with those of adult chickens. 2. 2. Blood cell amino acid concentrations were almost one order of magnitude higher than those of plasma, with higher values than those found in mammalian erythrocytes. 3. 3. This difference may be due to the capability for protein synthesis of the nucleated cells coupled with a postulated utilization of amino acids as fuel. 4. 4. The most common pattern of individual plasma amino acid levels was a slight rise at hatching followed by a large decrease, with minimal values for adults. 5. 5. The patterns in the cells did not always coincide with those for plasma. 6. 6. Total blood amino acid levels increased steadily during the period studied due to the increase in intracellular amino acids, giving rise to increasing blood-cell/plasma concentration ratios. 7. 7. These changes showed higher availability of plasma amino acids just after hatching, while the cell concentrations increased steadily to the maximum values in adults. 8. 8. The increase in alanine levels in cells with little changes in plasma can be correlated with the role of this amino acid as the main 2-amino nitrogen carrier in the avian bloodstream. 9. 9. The high amino acid levels in the cells suggest that these cells act as inter-organ transporters and reservoirs of amino acids, they have a different role in their handling and metabolism from those of mammals.

In vitro uptake of labeled amino acids by red blood cells of children with protein-calorie malnutrition

The in vitro uptake of 14C-glycine, 14C-leucine and 35S-methionine by red blood cells as well as the red blood cells and plasma amino acid patterns were studied in 20 children with protein-calorie malnutrition. Blood samples were obtained from each patient on admission, following clinical recovery and, when possible, several months later. Amino acid uptake as well as levels of red blood cells and plasma amino acids are quantitatively changed in protein-calorie malnutrition. Significantly increased uptake of 14C-glycine but decreased uptake of 14C-leucine and 35S-methionine were observed in patients on admission. Following clinical recovery the uptake values of all three amino acids were markedly reduced to levels significantly below normal. Several months later values for glycine and leucine uptake were found to be normal. No significant correlation, however, was found between glycine, leucine, or methionine uptake values and concentrations of these amino groups in RBCs or plasma of patients. It is concluded that the elevations observed in red blood cell amino acids of protein-calorie malnutrition patients are not purely a result of increased amino acid uptake of RBCs and that normalization of both amino acid uptake values and their concentrations in RBCs require longer than the treatment period.

Plasma and red blood cell amino acids of Egyptian children suffering from protein—calorie malnutrition

Plasma and red blood cell amino acids of Egyptian children suffering from protein—calorie malnutrition

Effect of infusion of a protein hydrolysate on blood cell amino acid distributions.

The relationships between the concentrations of unbound amino acids in the plasma and erythrocytes, together with amino acid utilization, are studied during the intravenous infusion of a protein hydrolysate in adults. Concentrations of alanine, proline, tyrosine, histidine, valine, phenalanine, leucine plus isoleucine, and urea increase in both the plasma and the erythrocytes. Lysine and methionine concentrations change much less in the erythrocytes than in the plasma. Ornithine and serine plus glycine concentrations in the erythrocytes do not change. It is concluded that amino acids with hydrophobic groups equilibrate readily whereas glycine and amino acids which contain charged or hydroxyl groups equilibrate poorly across the erythrocyte membrane. The changes in glutamine and alanine concentrations during and after infusion suggest that the infused amount of these two amino acids is less than optimum. An expression for amino acid uptake is given.