scholarly journals Lowering of plasma triiodothyronine level and sympathetic activity does not alter hypoalbuminaemia in rats fed on a diet of low protein concentration

1998 ◽  
Vol 79 (5) ◽  
pp. 455-462 ◽  
Author(s):  
Ana Lydia Sawaya ◽  
Peter G. Lunn
Keyword(s):  
Sympathetic Activity ◽  
Protein Concentration ◽  
Fat Deposition ◽  
Albumin Concentration ◽  
Elevated Plasma ◽  
Plasma Albumin ◽  
Plasma Insulin Concentration ◽  
Low Protein ◽  
Plasma Albumin Concentration ◽  
Plasma Triiodothyronine

Previous studies have described high plasma triiodothyronine (T3) concentrations and sympathetic activity in rats fed on low-protein diets. The present investigation examined how the nutritional status of rats fed on a low-protein diet was affected when these hormonal changes were reduced by drug administration. The low-protein diet (LP group) prevented growth, reduced plasma albumin levels, elevated plasma T3 concentration, and increased both the weight of the interscapular brown adipose tissue (BAT) and the activity of BAT cytochrome c oxidase (EC 1.9.3.1). Lowering the plasma T3 concentration (with carbimazole; CA group) elevated the plasma insulin concentration, promoted a small increase in the plasma albumin concentration and caused weight gain in comparison with the LP group. Reduction of sympathetic activity (with α-methyl-p-tyrosine; MT group) promoted a small elevation in plasma albumin concentration accompanied by a diminished T3 concentration, BAT weight, and an increase in fat deposition in relation to LP rats. In a second experiment, simultaneous lowering of the plasma T3 concentration and sympathetic activity (CA/MT group) resulted in weight gain associated with elevated plasma insulin concentration and fat deposition and a marked reduction in BAT cytochrome c oxidase activity. However no change in the hypoalbuminaemia was observed. The results of the present study suggest that in spite of the previously described increase in metabolic rate in rats fed on a diet with low-protein concentration when compared with controls, the mechanisms involved in the control of BAT activity and fat deposition seem to be independent of those which cause liver protein depletion and hypoalbuminaemia.

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

1977 ◽  
Vol 37 (1) ◽  
pp. 127-134 ◽  
Author(s):  
W. A. Coward ◽  
M. B. Sawyer
Keyword(s):  
Body Weight ◽  
Plasma Volume ◽  
Whole Body ◽  
Albumin Concentration ◽  
Plasma Albumin ◽  
Mean Values ◽  
Experimental Animals ◽  
Low Protein ◽  
Protein Diets ◽  
Plasma Albumin Concentration

1. From 5 weeks of age, control and experimental rats were given diets containing 210 and 31 g protein/kg respectively, and killed for analysis at 0, 2, 5, 8, 12 and 20 d after the start of the experiment. At these times estimates were made of plasma albumin concentration, plasma volume and total vascular and extravascular albumin mass.2. Plasma albumin concentrations were significantly lower in the experimental animals when compared to controls at 8, 12 and 20 d but plasma volumes (ml/kg body-weight) tended to be greater in the former animals. Total vascular albumin mass (g/kg body-weight) was significantly less in experimental animals compared to controls at 8 and 20 d, but was significantly reduced below values at 0 d only at 20 d.3. Extravascular albumin mass (g/kg body-weight) was significantly lower in experimental animals in comparison with controls at 2, 5, 8, 12 and 20 d and significantly reduced below values at 0 d at 5, 8, 12 and 20 d.4. Whole-body albumin mass was significantly reduced at 5, 8, 12 and 20 d when compared both with controls killed at the same time and animals killed at 0 d. Measurement of the ratio, extravascular albumin mass: vascular albumin mass indicated a significant redistribution of whole-body albumin mass at 5 and 20 d and mean values for this ratio were always lower in experimental animals than in controls.5. It was concluded that measurement of plasma albumin concentration does not indicate the true extent of whole-body albumin losses in protein deficiency since total vascular albumin mass is, to some extent, maintained at the expense of extravascular albumin mass.

scholarly journals Reasons why hypoalbuminaemia may or may not appear in protein-energy malnutrition

1977 ◽  
Vol 38 (1) ◽  
pp. 115-126 ◽  
Author(s):  
W. A. Coward ◽  
R. G. Whitehead ◽  
P. G. Lunn
Keyword(s):  
Amino Acid ◽  
Dietary Restriction ◽  
Protein Energy Malnutrition ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Albumin Concentration ◽  
Plasma Albumin ◽  
Low Protein ◽  
Protein Energy ◽  
Plasma Albumin Concentration

1.Investigations have been carried out in experimentally-malnourished rats in an attempt to explain the reasons for the development of the two main forms of protein-energy malnutrition in children, kwashiorkor and marasmus.2.Isoenergetic diets with values for protein: energy (P:E) of 0.21 (control diet; C) 0.032 (low-protein diet; LP) and 0.005 (very-low-protein diet; VLP) were fed to groups of twenty-six rats either ad lib. or in restricted amounts from 5 weeks of age. Rats were killed at the start of the experiment and 1, 2 and 3 or 4 weeks later. Estimations were made of plasma albumin, insulin, corticosterone and amino acid concentrations and of the total protein content of the gastrocnemius muscles and liver.3.Rats given diet LP ad lib. gained weight slowly and by week 1 plasma albumin concentration was slightly reduced. Rats given diet VLP ad lib. gradually lost weight and plasma albumin concentrations decreased continuously.4.In contrast the major effect of dietary restriction during the first 2 weeks of the experiment was to maintain plasma albumin concentrations at normal values, irrespective of the diet given.5.At later stages, however, when the ‘restricted’ animals had become very severely wasted, albumin concentrations decreased rapidly to values approaching those found in rats given diet VLP ad lib.6.When diets LP and VLP were given ad lib. body protein was proportionally distributed in favour of muscle rather than liver. For ‘restricted’ rats the reverse was true, at least up to the time when plasma albumin concentration began to decrease.7.Plasma corticosterone concentrations increased and insulin concentrations decreased when diets LP and VLP were fed in both an ad lib. and a ‘restricted’ regimen but the effects were significantly greater in the latter situation.8.Ad lib. feeding of diets LP and VLP produced a distorted plasma amino acid pattern resembling that of kwashiorkor, but although dietary restriction resulted in a decrease in total amino acid concentration, the plasma concentration ratio, non-essential amino acids:essential amino acids was virtually unaffected.9.It was concluded that whilst the lower the protein concentration in the diet the greater is the extent of hypoalbuminaemia which develops, dietary restriction with an increase in plasma glucocorticoid concentration and body-wasting can initially delay the development of the hypoalbuminaemia. However, in the final stages of wasting which ensue, low plasma albumin concentrations can appear because of a failure of the mechanisms which had earlier been able to preserve them at normal levels. It is possible that these two separate and distinct routes to hypoalbuminaemia observed in this study may have parallels in human situations in developing countries.

Protein losing enteropathy associated with Nippostrongylus brasiliensis infestation and its impact on albumin homoeostasis in rats fed two levels of dietary protein

1986 ◽  
Vol 70 (5) ◽  
pp. 469-475 ◽  
Author(s):  
P. G. Lunn ◽  
C. A. Northrop ◽  
R. H. Behrens ◽  
J. Martin ◽  
M. Wainwright
Keyword(s):  
Protein Diet ◽  
Low Protein Diet ◽  
Albumin Concentration ◽  
Nippostrongylus Brasiliensis ◽  
Protein Loss ◽  
Plasma Albumin ◽  
Protein Food ◽  
Protein Losing Enteropathy ◽  
Low Protein ◽  
Plasma Albumin Concentration

1. Alterations in plasma albumin concentration and gastrointestinal permeability have been investigated in rats infected with the nematode Nippostrongylus brasiliensis and fed adequate or low protein diets. 2. Infection caused only minor changes in growth and food consumption of well nourished rats but resulted in significant reductions in those fed the low protein diet. 3. Animals in both dietary groups were able to mount an immune response beyond day 10 postinfection (p.i.) which caused expulsion of the parasites, but this was less effective in rats fed the low protein food. 4. Uninfected rats fed the low protein diet had significantly lower plasma albumin concentrations than their well nourished counterparts. Animals of both dietary groups showed a progressive reduction in plasma albumin concentration as the infection developed but values returned towards normal as the parasites were expelled. 5. The reduction in plasma albumin concentration was closely associated with increases in gastrointestinal leakage of plasma protein but losses were far greater in the protein deficiency animals. Beyond day 10 p.i. protein loss decreased in both dietary groups and by day 21 p.i. had returned to normal in well nourished animals but not those fed the low protein diet. 6. Intestinal permeability measured by the lactulose:mannitol ratio technique gave similar results to the protein loss data. Permeability increased as the infection progressed then fell as the worms were expelled but remained above control values in infected protein deficient animals. 7. Overall, animals fed the low protein diet were more severely affected by the parasite than were their well fed counterparts. The data clearly demonstrated that the combined effects of infection and dietary deficiency resulted in a more severe reduction in plasma albumin values than either factor produced alone. The results are discussed with reference to the aetiology of hypoalbuminaemia and kwashiorkor in man.

scholarly journals Synthesis rate of plasma albumin is a good indicator of liver albumin synthesis in sepsis

2000 ◽  
Vol 279 (2) ◽  
pp. E244-E251 ◽  
Author(s):  
Benoît Ruot ◽  
Denis Breuillé ◽  
Fabienne Rambourdin ◽  
Gerard Bayle ◽  
Pierre Capitan ◽  
...  
Keyword(s):  
Synthesis Rate ◽  
Albumin Concentration ◽  
Liver Protein ◽  
Mrna Levels ◽  
Albumin Synthesis ◽  
Plasma Albumin ◽  
Period 2 ◽  
Fractional Synthesis ◽  
Plasma Albumin Concentration

Plasma albumin is well known to decrease in response to inflammation. The rate of albumin synthesis from both liver and plasma was measured in vivo by use of a large dose ofl-[2H3-14C]valine in rats injected intravenously with live Escherichia coli and in pair-fed control rats during the acute-phase period (2 days postinfection). The plasma albumin concentration was reduced by 50% in infected rats compared with pair-fed animals. Infection induced a fall in both liver albumin mRNA levels and albumin synthesis relative to total liver protein synthesis. However, absolute liver albumin synthesis rate (ASR) was not affected by infection. In plasma, albumin fractional synthesis rate was increased by 50% in infected animals compared with pair-fed animals. The albumin ASR estimated in the plasma was similar in the two groups. These results suggest that hypoalbuminemia is not due to reduced albumin synthesis during sepsis. Moreover, liver and plasma albumin ASR were similar. Therefore, albumin synthesis measured in the plasma is a good indicator of liver albumin synthesis.

Plasma protein synthesis in patients with low-grade nephrotic proteinuria

2001 ◽  
Vol 280 (4) ◽  
pp. E591-E597 ◽  
Author(s):  
Michela Zanetti ◽  
Rocco Barazzoni ◽  
Giacomo Garibotto ◽  
Gloria Davanzo ◽  
Carlo Gabelli ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Grade ◽  
Albumin Concentration ◽  
Turnover Rates ◽  
Plasma Albumin ◽  
Nephrotic Proteinuria ◽  
Plasma Albumin Concentration ◽  
Normal Albumin ◽  
Secretion Rates

Overt nephrotic syndrome is characterized by albumin and fibrinogen hyperproduction and reduced very low density lipoprotein apolipoprotein B-100 (VLDL apoB-100) clearance. Whether similar changes also occur in low-grade proteinuria is not known. Thus we measured albumin, fibrinogen, and VLDL apoB-100 kinetics in six patients with modest proteinuria and normal creatinine clearance (P) and in ten control subjects (C) by leucine tracer infusion and precursor-product relationships. In P, plasma albumin concentration was decreased ( P < 0.003), whereas concentrations of fibrinogen and VLDL apoB-100 were increased ( P < 0.001). In P, albumin fractional secretion rate (FSR) was increased ( P < 0.01), fibrinogen FSR was normal, and VLDL apoB-100 FSR was decreased ( P < 0.03). As a result, in P, absolute secretion rates (ASR) of albumin and fibrinogen were increased ( P < 0.03), whereas VLDL apoB-100 ASR was normal. Albumin FSR was inversely correlated to oncotic pressure in P but not in C. These findings suggest that low-grade nephrotic proteinuria is characterized by simultaneous multiple alterations in turnover rates of albumin, fibrinogen, and VLDL apoB-100. Their pathogenesis, however, appears to be multifactorial.

Elevated pulmonary lymph flow and protein content during status epilepticus in sheep

1982 ◽  
Vol 52 (1) ◽  
pp. 91-95 ◽  
Author(s):  
R. P. Simon ◽  
L. L. Bayne ◽  
R. F. Tranbaugh ◽  
F. R. Lewis
Keyword(s):  
Driving Force ◽  
Left Atrial ◽  
Cervical Spinal Cord ◽  
Lymph Flow ◽  
Base Line ◽  
Albumin Concentration ◽  
Plasma Albumin ◽  
Protein Ratio ◽  
Pulmonary Arterial ◽  
Plasma Albumin Concentration

The pathophysiology of postictal pulmonary edema was investigated by inducing seizures with bicuculline in nine paralyzed, halothane-anesthetized sheep and measuring of pulmonary lymphatic flow, pulmonary arterial and left atrial pressures, and lymph and plasma albumin concentration. Pulmonary microvascular pressure and transcapillary albumin conductance were calculated. Seizures transiently (less than 15 min) elevated microvascular pressure in all animals; lymph flow increased greater than twofold in response to the increased hydrostatic driving force. However, the elevation in lymph flow, with a stable lymph-to-plasma protein ratio and doubled transcapillary albumin conductance, persisted for the duration of the experiment, more than 3 h after microvascular pressure returned to base line. These changes were neurally mediated because they were blocked by cervical spinal cord transection in four additional animals.

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