Whole-body albumin mass and distribution in rats fed on low-protein diets

Coward, W. A.; Sawyer, M. B.

doi:10.1079/bjn19770012

Cited by 24 publications

(9 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Plasma albumin levels dropped significantly in the SDR on the low-protein diet, as has been seen in many previous studies (Kirsch et al 1968 ;Coward & Sawyer, 1977;Lunn & Austin, 1983). However, this fall could only account for part of the fall in total plasma protein concentreation in the SDR.…”

Section: Low-protein Diet Effects On Plasma Protein Spectrumsupporting

confidence: 84%

Plasma proteins in growing analbuminaemic rats fed on a diet of low-protein content

Joles¹,

Jansen

Laan

et al. 1989

Br J Nutr

View full text Add to dashboard Cite

I . Analbuminaemic and Sprague-Dawley (control) rats were fed on low-(60 g/kg) protein and control (200 g protein/kg) diets ud lib. from weaning. Males and females were studied separately. Body-weight and plasma protein concentrations were determined at 10 d intervals from 25 to 75 d of age. Electrophoresis of plasma proteins was performed in samples from day 75. Extracellular fluid volume was measured at 10 d intervals from day 45 onwards. Colloid osmotic pressure was measured in plasma and interstitial fluid (wick technique) at the start and end of the trial.2. Body-weight increased much less on the low-protein diet than on the normal diet in both strains and sexes. The growth retardation was slightly more pronounced in the male analbuminaemic rats than in the male Sprague-Dawley controls.3. Plasma protein concentration increased during normal growth in all groups, particularly in the female analbuminaemic rats. This increase was reduced by the 60 g protein/kg diet in all groups, with the exception of the male analbuminaemic rats.4. Differences in plasma colloid osmotic pressure were similar to those seen in plasma protein concentration. Interstitial colloid osmotic pressure was higher in the control rats than in the analbuminaemic ones. The interstitial colloid osmotic pressure increased during growth in the control but not in the analbuminaemic rats. The difference in interstitial colloid osmotic pressure between the strains was maintained during low-protein intake, but at a lower level than during normal protein intake.5. Subtracting interstitial from plasma colloid osmotic pressure, resulted in a rather similar transcapillary oncotic gradient in the various groups at 75 d, both on the control protein diet (1 1-14 mmHg), and on the lowprotein diet (9-1 1 mmHg).6 . All protein fractions were reduced to a similar extent by the low-protein diet in the control rats, whereas in the analbuminaemic rats protein fractions produced in the liver were more severely depressed.7. Extracellular fluid volume as a percentage of body-weight was similar in all groups, and decreased with increasing age.8. In conclusion, the analbuminaemic rats were able to maintain the transcapillary oncotic gradient on both diets by reducing the interstitial colloid osmotic pressure. Oedema was not observed.9. Despite the absence of albumin, the protein-malnourished analbuminaemic rat is no more susceptible to hypoproteinaemia and oedema than its normal counterpart.Hypoproteinaemia and growth retardation are well-known sequelae of protein-energy malnutrition in growing children. The clinical syndrome is called marasmus when severe growth retardation prevails, whereas in kwashiorkor the growth retardation is less severe, but is accompanied by hypoproteinaemia and oedema (Anon., 1970;Alleyne et al. 1977). What determines the development of one clinical picture rather than the other is not precisely known (Coward & Lunn, 1981). It seems, however, that the hypoproteinaemia in kwashiorkor, which in fact concerns suppressed albumin synthesis rathe...

show abstract

Section: Low-protein Diet Effects On Plasma Protein Spectrumsupporting

confidence: 84%

Plasma proteins in growing analbuminaemic rats fed on a diet of low-protein content

Joles¹,

Jansen

Laan

et al. 1989

Br J Nutr

View full text Add to dashboard Cite

show abstract

“…The albumin concentration in serum may be maintained at the expense of extravascular albumin as reported for rats fed lowprotein diets. 4 The size of the extracellular albumin pool in hepatic tissue from cancer patients may have decreased, as indicated by the trend to a lower value of hepatic content of albumin, which was also observed in previous animal studies8 This points to the possibility of altered distribution of the exchangeable pool of albumin, which also implies enhanced albumin degradation in these patients. A low albumin concentration in the extracellular space and, thus, a decreased colloid osmotic pressure, may be another factor contributing to the maintainance of albumin synthesis capacity.22…”

mentioning

confidence: 65%

Albumin and hepatic protein synthesis in patients with early cancer

Lundholm

Karlberg

Scherstén

1980

Cancer

View full text Add to dashboard Cite

The synthesis capacity of albumin and hepatic proteins was studied in vitro in hepatic tissue from 21 patients with early-stage cancer and without liver metastasis and from 26 control subjects. Hepatic tissue was obtained intraoperatively and incubated under protein synthesizing conditions. Albumin was isolated with monospecific antiserum. Cancer patients showed an increased capacity for hepatic protein synthesis and an unchanged capacity for synthesis and intracellular transport of albumin. The ratio between the synthesis of hepatic protein and albumin was statistically significantly increased in cancer patients. The albumin synthesis was inversely correlated to a body weight index in cancer patients (r = -0.62), suggesting the presence of a compensatory mechanism for enhanced albumin synthesis in patients who are unable to ingest sufficient quantities of nutrients to supply the demands of the host and the tumor.Cancer 46:71-76, 1980. LTERED ALBUMIN METABOLISM and increasedA hepatic protein synthesis are frequent findings in cancer patients and in tumor-bearing animals .3*7,14,15,-20,2527 Of all factors regulating albumin synthesis, the nutritional state appears to be the most important.16,22 Since reduced caloric intake and weight reduction are characteristic features of cancer, even in its early stages, one would expect early decreases in albumin synthesis in cancer patients. However, Hradec has reported increased albumin synthesis and turnover rate in tumor-bearing animals from the first moment of tumor "take".* The albumin synthesis rate was high, irrespective of magnitude and growth-rate of the tumor or the composition of the diet. In agreement with these results, Clark and Goodlad found that diet and caloric intake did not affect the action of the Walker 256 carcinoma on hepatic protein and nucleic acid levels.2 Hence, factors other than the ordinary nutritional state seem to be of primary importance for the regulation of hepatic protein metabolism in cancer disease. In line with this suggestion, the concept of hormonal agents or signal factors affecting metabolic processes has received increasing attention.26

show abstract

“…It is extremely difficult to relate these dietinduced changes in albumin synthesis rates directly to plasma albumin concentrations. The level of this protein is affected not only by the synthesis rate but by alterations in catabolism and distribution between intraand extra-vascular compartments [Coward and Sawyer, 1977). Moreover, the values ob tained for albumin production under con trolled experimental conditions should be re garded as an estimate of the synthesizing capacity.…”

Section: Discussionmentioning

confidence: 99%

Albumin-Synthesizing Capacity of Hepatocytes Isolated from Rats Fed Diets Differing in Protein and Energy Content

Smith

Lunn²

1984

Ann Nutr Metab

View full text Add to dashboard Cite

The rate of albumin synthesis has been estimated in hepatocytes prepared from groups of rats maintained on diets of different protein content. These diets were fed either ad libitum or at 50% restriction of ad libitum consumption. The data show that the physiological capacity of hepatocytes to synthesize albumin varies with dietary intake. Albumin production by cells prepared from animals fed ad libitum was directly related to the protein energy:total energy ratio of the food. Restricting consumption of the control diet to 50% of ad libitum intake did not reduce albumin synthesis rates, and similar restriction of the low protein diets ameliorated some of the depression in albumin production observed in hepatocytes isolated from animals fed the same diets ad libitum. The results are discussed with reference to the occurrence of hypoalbuminaemia in children with protein-energy malnutrition.

show abstract

Whole-body albumin mass and distribution in rats fed on low-protein diets

Cited by 24 publications

References 19 publications

Plasma proteins in growing analbuminaemic rats fed on a diet of low-protein content

Plasma proteins in growing analbuminaemic rats fed on a diet of low-protein content

Albumin and hepatic protein synthesis in patients with early cancer

Albumin-Synthesizing Capacity of Hepatocytes Isolated from Rats Fed Diets Differing in Protein and Energy Content

Contact Info

Product

Resources

About