The effect of dietary protein deficiency on albumin synthesis and on the concentration of active albumin messenger ribonucleic acid in rat liver

Pain, Virginia M.; Clemens, M J; Garlick, Peter J.

doi:10.1042/bj1720129

Cited by 70 publications

(25 citation statements)

References 28 publications

(26 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1). This value is considerably lower than that observed in hypophysectomized (15,16) or thyroidectomized (27) animals or in rats fed a protein-deficient diet (25,28). In spite of the marked reduction in the rate of albumin synthesis, the serum albumin level in rats 6 days after the induction of diabetes was unchanged from the normal level (29), suggesting a concomitant decrease in the rate of albumin degradation.…”

Section: Resultscontrasting

confidence: 39%

Correlation of albumin production rates and albumin mRNA levels in livers of normal, diabetic, and insulin-treated diabetic rats.

Peavy¹,

Taylor²,

Jefferson³

1978

Proc. Natl. Acad. Sci. U.S.A.

155

View full text Add to dashboard Cite

We have studied the effects of alioxan-induced diabetes and subsequent insulin replacement on albumin and total hepatic protein synthesis. Diabetes resulted in a reduction to approximately 20% of normal in albumin synthesis relative to the rate of total protein synthesis in vivo and a reduction to 10% in the absolute rate of albumin secretion by perfused livers. In contrast, the synthesis of total secretory protein and retained hepatic protein was affected to a lesser extent by diabetes.Treatment of diabetic rats with insulin restored rates of albumin and total hepatic protein synthesis to normal levels. The molecular basis of these alterations in albumin synthesis was investigated by examining albumin mRNA levels in livers of normal, diabetic, and insulin-treated diabetic animals. The level of albumin mRNA, whether assayed by cell-free translation or by hybridization to a specific complementary DNA probe, was markedly decreased in livers of diabetic animals and was restored to normal by insulin treatment. These changes occurred in parallel with changes in the rates of albumin secretion observed in perfused liver, suggesting that albumin mRNA content is the primary factor responsible for altering rates of albumin synthesis under these conditions.A role for insulin in regulating protein synthesis in liver has not been clearly established. In rats, experimentally induced diabetes caused no change in liver protein synthesis rates in vivo, while synthesis rates in skeletal muscle and heart were markedly impaired (1). These findings are supported by studies using perfused tissues from normal rats in which measurements of protein synthesis showed that addition of insulin had no effect on the synthesis of hepatic proteins (2) but stimulated the synthesis of skeletal muscle (3) and heart (4) proteins. While some workers have reported that insulin stimulates liver protein synthesis (5), rates of protein synthesis were not determined rigorously in these experiments.Studies of protein synthesis in liver are complicated by the fact that this tissue synthesizes both proteins for export and intracellular proteins. The studies mentioned above measured primarily the synthesis of intracellular proteins. Other studies with perfused livers (6) or isolated hepatocytes (7) indicated an impaired secretion of proteins in diabetic rats. Such a defect may relate to the marked disruption and disorganization of the rough endoplasmic reticulum observed in liver of diabetic rats (8-10), as export proteins are synthesized almost exclusively on the rough endoplasmic reticulum (11).In the studies presented here, we have investigated the effect of alloxan-induced diabetes and subsequent insulin replacement on albumin and total protein production in vivo and in perfused livers, and have correlated the observed changes in albumin synthesis with changes in albumin mRNA levels. Diabetes resulted in a marked decrease in albumin synthesis and secretion in vivo and in perfused livers, with a corresponding decrease in the albumin mRNA level. T...

show abstract

Section: Resultscontrasting

confidence: 39%

Correlation of albumin production rates and albumin mRNA levels in livers of normal, diabetic, and insulin-treated diabetic rats.

Peavy¹,

Taylor²,

Jefferson³

1978

Proc. Natl. Acad. Sci. U.S.A.

155

View full text Add to dashboard Cite

show abstract

“…Pain, Clemens & Garlick, 1978). Two factors are concerned in the effect of malnutrition on general protein synthesis: a reduction in the amount of ribosomal RNA and a reduction in what has been called RNA 'activity' (Millward, Garlick, James, Nnanyelugo & Ryatt, 1973), i.e.…”

Section: The Effect Of the Prevailing Food Intake On Protein Turnovermentioning

confidence: 99%

Protein Turnover With Special Reference to Man

1984

View full text Add to dashboard Cite

This review is concerned with rates of N flux in the living animal rather than with mechanisms of protein synthesis and breakdown at the cellular level. Methods of measuring protein turnover in the whole body are discussed, with special emphasis on studies in man, and results obtained by different methods have been compared. Aspects of whole body protein turnover which are of physiological interest include its relation to body size, growth and development, energy metabolism and food intake. There are substantial increases in protein turnover in injury, and changes that occur in exercise are beginning to be explored. From the physiological point of view these results point the need for future research along two main lines. The first is that of regulation: a wide variety of hormones stimulate or repress protein synthesis and breakdown, with varying actions in different tissues. These effects, however, do not in themselves explain the mechanism by which a balance between synthesis and breakdown is maintained. Secondly, the fact that all cellular proteins are in a dynamic state poses questions about the relation between structure and function in tissues such as muscle and brain, which physiologists have hardly begun to tackle.

show abstract

“…5) The deprivation of dietary protein lowered albumin biosynthesis 6 ) and its hepatic mRNA content, 7 ,8) and the limitation of amino acids also reduced the synthesis of albumin in rat hepatocytes 9 ) and mouse hepatoma cells. 10 ) We assumed that the dietary supplementation of methionine and threonine would ameliorate the reduced level of serum albumin and its liver mRNA in rats fed a non-protein diet.…”

mentioning

confidence: 99%

Elevation of the Hepatic Level of Albumin mRNA in Rats Fed a Non-protein Diet Supplemented with Sulfur-containing Amino Acids and Threonine

Hitomi

Ito

Chiba

et al. 1993

Bioscience, Biotechnology, and Biochemistry

View full text Add to dashboard Cite

The effect of dietary protein deficiency on albumin synthesis and on the concentration of active albumin messenger ribonucleic acid in rat liver

Cited by 70 publications

References 28 publications

Correlation of albumin production rates and albumin mRNA levels in livers of normal, diabetic, and insulin-treated diabetic rats.

Correlation of albumin production rates and albumin mRNA levels in livers of normal, diabetic, and insulin-treated diabetic rats.

Protein Turnover With Special Reference to Man

Elevation of the Hepatic Level of Albumin mRNA in Rats Fed a Non-protein Diet Supplemented with Sulfur-containing Amino Acids and Threonine

Contact Info

Product

Resources

About