scholarly journals PLASMA PROTEIN METABOLISM—NORMAL AND ASSOCIATED WITH SHOCK

1944 ◽  
Vol 80 (6) ◽  
pp. 455-475 ◽  
Author(s):  
R. M. Fink ◽  
T. Enns ◽  
C. P. Kimball ◽  
H. E. Silberstein ◽  
W. F. Bale ◽  
...  

Labeled plasma proteins are produced by administering to dogs the amino acid lysine synthesized with heavy nitrogen. Such labeled proteins are apparently indistinguishable biologically from proteins of normal isotope concentration. Labeled plasma proteins, as plasma, injected into normal dogs pass out of the blood stream at an initially rapid but constantly decreasing non-logarithmic rate. This outflow is balanced by a simultaneous inflow of plasma proteins from the tissues. Fifty per cent of the labeled protein is out of the blood stream in about 24 hours; 75 per cent in about 6 days. Shock due to trauma of intestine or leg shows a dilution curve of labeled plasma protein not unlike that of the normal dog. If anything, dilution appears a little less rapid in shock. Since the usual shrinkage of plasma volume and plasma protein mass is present in these shocked dogs, these data are compatible with a decreased inflow of protein into the plasma during shock. Methods are described which are suitable for the use of heavy nitrogen incorporated in the epsilon group of lysine and its subsequent analysis in body fluids. These data may indicate that the plasma proteins are normally in constant and rapid exchange with a mobile pool of body protein.

1935 ◽  
Vol 62 (3) ◽  
pp. 353-258 ◽  
Author(s):  
James B. McNaught ◽  
Francis M. Woods ◽  
Virgil Scott

A non-splenectomized dog, on a vitamin-adequate basal diet, in the course of a plasmapheresis experiment, developed an uncontrollable anemia associated with the presence of bodies in or on the erythrocytes, indistinguishable from the descriptions of Bartonella canis. The normal plasma protein level of 7.3 per cent was reduced to 4.1 per cent by diet and the removal of 5354 ml. of whole blood in 33 bleedings. The Bartonella infection was transferred to a splenectomized dog by an intravenous injection of whole blood. Each animal was apparently sterilized by one injection of neoarsphenamine equivalent to 15 mg. per kilo weight. It is possible that the spleen liberates some substance into the blood stream which has an inhibitory effect upon a latent Bartonella infection and that this protective substance was diminished by the many bleedings associated with the lowering of plasma proteins in the non-splenectomized dog and was lacking in the inoculated splenectomized dog.


1974 ◽  
Vol 141 (3) ◽  
pp. 655-665 ◽  
Author(s):  
J. Ho ◽  
K. N. Jeejeebhoy ◽  
R. H. Painter

A two-step method for the separation of five different plasma proteins on a preparative scale, which is capable of being extended to allow the separation of other plasma proteins, is described. The proteins separated were fibrinogen, two α1-glycoproteins, albumin and transferrin. The α1-glycoproteins were characterized in terms of electrophoretic mobility, ultracentrifugal and immunological characteristics. By using this method, it was shown that a single sample of plasma could be fractionated to yield purified proteins in sufficient quantity to simultaneously measure the synthesis of the two α1-glycoproteins, albumin and transferrin in the rat with McFarlane's technique (McFarlane, 1963; Reeve et al., 1963; McFarlane et al., 1965).


1945 ◽  
Vol 81 (5) ◽  
pp. 515-537 ◽  
Author(s):  
L. J. Zeldis ◽  
E. L. Alling

Electrophoretic patterns of normal dog plasma in veronal buffer at pH 8.5 are shown to be essentially similar to patterns of human plasma. Dog albumin has a higher mobility than human albumin and in a mixture of dog and human plasmas migrates as a partially separated peak. Normal dog plasma frequently shows four alpha globulin peaks. Rates of restoration of plasma protein components in dogs subjected to acute plasmapheresis have been studied by electrophoresis. During the first 24 hours following such acute depletion, appreciable quantities of all electrophoretic components of the plasma proteins enter the circulating blood stream even when food is not given and has not been given for 12 hours before plasmapheresis. In such fasting periods albumin and total globulin appear in approximately the proportions present in normal plasma. Alpha and beta globulins continue relatively elevated during subsequent days in which caloric and protein intakes are adequate for weight and nitrogen gains. Initial albumin levels, however, are regained more slowly than those of total globulin. The relative proportions of the electrophoretic components of plasma proteins may be disturbed from normal following a single acute depletion for as long as 2 to 3 weeks after the total protein level has returned to normal. Abnormally high beta globulin and fibrinogen, but a low albumin, were found in a dog with an acute and chronic cholangitis and hepatitis. Similar elevation of gamma globulin was noted in a dog in which a hemolytic reaction occurred.


1955 ◽  
Vol 101 (6) ◽  
pp. 617-626 ◽  
Author(s):  
G. H. Whipple ◽  
R. B. Hill ◽  
R. Terry ◽  
F. V. Lucas ◽  
C. L. Yuile

Plasma proteins tagged in vivo by feeding D-L-lysine-ϵ-C14 to donor dogs have been administered to pregnant dogs by both oral and intravenous routes. A relatively small percentage of the C14 activity originally incorporated in these proteins is found to pass from mother to fetus after intravenous injection. The amount transferred tends to increase with the length of gestation period and total number of fetuses. Plasma protein labeled with I131 does not cross the placenta in the dog, but does in the rabbit. Evans blue dye does not cross the placenta of the dog. After oral administration of labeled plasma protein or lysine, C14 is transferred promptly and in considerable quantity to the fetus. Labeled plasma proteins disappear more rapidly from the circulation of pregnant than of normal dogs. This increased metabolic turnover occurs without excretion of any excess waste metabolites. The chorionic epithelium, gram for gram, is probably 2 to 3 times as active as the hepatic epithelium in protein metabolism. These findings indicate an important placental function related to maternal and fetal protein metabolism. While the placenta utilizes maternal plasma proteins and amino acids, in a quantitative sense the latter appear to supply the major nitrogen needs of the growing fetus.


1955 ◽  
Vol 102 (6) ◽  
pp. 713-723 ◽  
Author(s):  
G. H. Tishkoff ◽  
C. L. Yuile ◽  
F. S. Robscheit-Robbins ◽  
G. H. Whipple

Red cell stroma protein and hemoglobin can be labeled by feeding C14 lysine during periods of active blood regeneration following anemia. Stroma proteins are produced and a maximum concentration of the C14 label appears 2 to 3 days earlier than with hemoglobin,—which is to say that stroma building precedes hemoglobin construction. The concentration of isotope in stroma protein may exceed its concentration in hemoglobin during regeneration following anemia due to blood loss. Diets favorable for hemoglobin regeneration may force the hemoglobin isotope concentration above that of the stroma protein. In hemolytic anemias great reserves of red cell building material are stored in the body. These stores may modify the curves of isotope concentration in red cells during the recovery periods. When finally formed, the mature red cells show little or no evidence of participation in general body protein metabolism during their life in the circulation.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 143-143
Author(s):  
Holland C Dougherty ◽  
Hutton Oddy ◽  
Mark Evered ◽  
James W Oltjen

Abstract Target protein mass at maturity is a common “attractor” used in animal models to derive components of animal growth. This target muscle protein at maturity, M*, is used as a driver of a model of animal growth and body composition with pools representing muscle and visceral protein; where viscera is heart, lungs, liver, kidneys, reticulorumen and gastrointestinal tract; and muscle is non-visceral protein. This M* term then drives changes in protein mass and heat production, based on literature data stating that heat production scales linearly with protein mass but not liveweight. This led us to adopt a modelling approach where energy utilization is directly related to protein content of the animal, and energy not lost as heat or deposited as protein is fat. To maintain continuity with existing feeding systems we estimate M* from Standard Reference Weight (SRW) as follows: M* (kJ) = SRW * SHRINK * (1-FMAT) * (MUSC) * (CPM)* 23800. Where SRW is standard reference weight (kg), SHRINK is the ratio of empty body to live weight (0.86), FMAT is proportion of fat in the empty body at maturity (0.30), MUSC is the proportion of empty body protein that is in muscle (0.85), CPM is the crude protein content of fat-free muscle at maturity (0.21), and 23800 is the energetic content (kJ) of a kilogram of crude protein. Values for SHRINK, FMAT, MUSC and CPM were derived from a synthesis of our own experimental data and the literature. For sheep, these values show M* to be: M* (kJ) = SRW * 0.86* (1-0.3) * 0.85 * 0.21 *23800 = SRW * 2557. This method allows for use of existing knowledge regarding standard reference weight and other parameters in estimating target muscle mass at maturity, as part of a model of body composition and performance in ruminants.


Author(s):  
Jorn Trommelen ◽  
Andrew M. Holwerda ◽  
Philippe J. M. Pinckaers ◽  
Luc J. C. van Loon

All human tissues are in a constant state of remodelling, regulated by the balance between tissue protein synthesis and breakdown rates. It has been well-established that protein ingestion stimulates skeletal muscle and whole-body protein synthesis. Stable isotope-labelled amino acid methodologies are commonly applied to assess the various aspects of protein metabolism in vivo in human subjects. However, to achieve a more comprehensive assessment of post-prandial protein handling in vivo in human subjects, intravenous stable isotope-labelled amino acid infusions can be combined with the ingestion of intrinsically labelled protein and the collection of blood and muscle tissue samples. The combined application of ingesting intrinsically labelled protein with continuous intravenous stable isotope-labelled amino acid infusion allows the simultaneous assessment of protein digestion and amino acid absorption kinetics (e.g. release of dietary protein-derived amino acids into the circulation), whole-body protein metabolism (whole-body protein synthesis, breakdown and oxidation rates and net protein balance) and skeletal muscle metabolism (muscle protein fractional synthesis rates and dietary protein-derived amino acid incorporation into muscle protein). The purpose of this review is to provide an overview of the various aspects of post-prandial protein handling and metabolism with a focus on insights obtained from studies that have applied intrinsically labelled protein under a variety of conditions in different populations.


1924 ◽  
Vol 39 (6) ◽  
pp. 921-929 ◽  
Author(s):  
G. C. Linder ◽  
C. Lundsgaard ◽  
D. D. Van Slyke ◽  
E. Stillman

1. We have not observed gross increases in plasma volume in glomerulonephritis, nephrosis, or nephrosclerosis, even when the concentration of plasma proteins was much below normal. Our results indicate the probability that "hydremic plethora" does not occur. 2. The low protein concentration frequently observed in the plasma in nephritis is not due to increased plasma volume but to a decrease of the total amount of plasma protein in the body. 3. Changes in plasma volume showed no constant relationship to changes in edema.


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