The requirements for serum albumin metabolism in subcellular fractions of liver and brain

Penn, N. W.

doi:10.1016/0006-3002(60)90078-0

Cited by 48 publications

(5 citation statements)

References 22 publications

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“…When taken in context with reports of decreased serum proteins and albumin in protein-deficient rats and humans (Hoffenberg et al, 1969) and similar effects noted for ruminants fed urea purified diets (Ludwick et al, 1972), the serum proteins may be acting as supplemental sources of amino acids to muscle tissue. The in vitro work of Penn (1960), which showed rapid catabolism of albumin following cellular uptake due to mitochondrial lysosomes, coupled with Schimke's (1977) theory on increased activity of cellular lysosomes in nutritional stress situations, supports the results observed in the present study for serum protein amino acid tissue exchange.…”

Section: Peptidessupporting

confidence: 88%

Transport and Hindlimb Exchange of Peptide and Serum Protein Amino Acids in Calves Fed Soy- or Urea-Based Purified Diets2

Danilson

Webb

Herbein

1987

Journal of Animal Science

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Holstein steer calves (130 kg) were used to monitor venoarterial concentration differences of plasma peptide and serum protein amino acids across the hindlimbs. Calves were fed purified diets containing soy protein or urea as the sole source of dietary N. Twenty-four hourly feedings per day were imposed to promote "steady-state" metabolism. Negative venoarterial differences of glutamic acid (P less than .10), valine (P less than .10), lysine (P less than .05) and histidine (P less than .01) were observed in soy-fed calves and isoleucine (P less than .10) in urea-fed calves from the peptide fraction. Negative venoarterial differences of amino acids from the peptide fraction were generally similar for the two dietary treatments, except for glutamic acid (P less than .01). A large negative venoarterial difference of glutamic acid was observed when soy protein was fed and, conversely, a large positive venoarterial difference was observed when urea was fed. Two groups of serum proteins were evaluated: fraction I (primarily globulins) and fraction II (primarily albumin). Hindlimb amino acid venoarterial concentration differences for soy-fed calves were inconsistent and nonsignificant for both fractions I and II. Conversely, hindlimb negative venoarterial concentration differences in urea-fed calves for both fractions I and II were large and statistically significant for many amino acids. Fraction II venoarterial differences were much greater than differences observed in fraction I. Soy and urea treatment differences were also much more pronounced in fraction II, being statistically significant for 8 of 17 amino acids. These data indicate venoarterial concentration differences of serum protein amino acids that react differently to varied nutritional regimens.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Peptidessupporting

confidence: 88%

Transport and Hindlimb Exchange of Peptide and Serum Protein Amino Acids in Calves Fed Soy- or Urea-Based Purified Diets2

Danilson

Webb

Herbein

1987

Journal of Animal Science

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“…However, these studies provide no information as to the specific organs involved in catabolism. Many other techniques have been utilized to try to obtain such information, including organ perfnsion (12), organ extirpation (13,14), and in vitro incubation of radiolabeled proteins with tissue slices (15) and subcelhilar fractions (16). However, no consensus has been reached regarding a major role for any individual organ in the catabolism of a specific protein.…”

mentioning

confidence: 99%

The Role of the Kidney in the Catabolism of Bence Jones Proteins and Immunoglobulin Fragments

Wochner

Strober

Waldmann

1967

The Journal of Experimental Medicine

267

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The role of the kidney in the catabolism of Bence Jones proteins, intact IgG molecules, and isolated L chains, Fab and Fc fragments of IgG, was studied. The proteins were purified, radioiodinated, and their survival times measured in nephrectomized, ureter-severed, and control mice. Active endogenous catabolism was the major factor in overall Bence Jones metabolism since excretion as proteinuria accounted for less than 25% of the total metabolism. The survival times of λ- and κ-type human Bence Jones proteins and the Bence Jones protein produced by mice with MPC-2 plasma cell tumor were exceedingly short in both unoperated and ureter-severed mice, with 50% of the injected protein catabolized in from 0.8–1.6 hr. In contrast, the survival of Bence Jones protein was markedly prolonged in nephrectomized animals, with 50% of the injected dose catabolized in from 9 to 17 hr. This ten-fold decrease in catabolic rate indicates that the kidneys are the major site of breakdown of Bence Jones proteins. Similar studies with other proteins indicated that the kidneys are also the major site for catabolism of isolated L chains but not of intact IgG molecules. The Fc immunoglobulin fragment was not catabolized and the Fab fragment only partially catabolized by the kidney. When ureter-severed animals were allowed to develop advanced uremia before being studied, the survival of Bence Jones protein was greatly prolonged, indicating that the catabolic process is impaired in the presence of uremia. The nature of this renal catabolism remains unknown. These observations suggest that the Bence Jones proteins and L chains observed in the urine of patients may reflect only a small fraction of such molecules synthesized by these patients. Furthermore, they provide an explanation for the prolongation of Bence Jones protein survival and the development of Bence Jones proteinemia observed in subjects with multiple myeloma and impaired renal function.

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“…[4][5][6][7][8][9] Studied after 48 hr of dialysis against EDTA and in the presence of iodoxeof "amino acid activating enzymes" ( 1.1 mg of total protein) prepared according to the method of Hoagland et al (15) was added to 20 ml of liver homogenate after 80 min of incubation. In some cases, 1 mg of ATP was simultaneously added with the "activating enzymes" and at 20-min interval for the rest of the experiment.…”

Section: Methodsmentioning

confidence: 99%

“…Complementary studies have indicated that the addition of adenosine-5'-triphosphate ( ATP) to preparations of intracellular organelles (4) or to whole tissue homogenates ( 5 , 6) greatly increase the rate of proteolysis, and that this activating effect is mediated by aspartic acid, presumably through the formation of an adenylate derivative (7). This activating effect of ATP was found to be widespread in the organs of the rat (6) and to be able to return to a normal level the reduced proteolytic activity of the liver of rats subjected to an acute stress (8).…”

mentioning

confidence: 99%

Protein Degradation at Neutral pH. Possible Enzymic and Control Mechanisms

1971

Experimental Biology and Medicine

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The requirements for serum albumin metabolism in subcellular fractions of liver and brain

Cited by 48 publications

References 22 publications

Transport and Hindlimb Exchange of Peptide and Serum Protein Amino Acids in Calves Fed Soy- or Urea-Based Purified Diets2

Transport and Hindlimb Exchange of Peptide and Serum Protein Amino Acids in Calves Fed Soy- or Urea-Based Purified Diets2

The Role of the Kidney in the Catabolism of Bence Jones Proteins and Immunoglobulin Fragments

Protein Degradation at Neutral pH. Possible Enzymic and Control Mechanisms

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