The response of liver albumin synthesis to infection in rats varies with the phase of the inflammatory process

2001 ◽  
Vol 102 (1) ◽  
pp. 107-114 ◽  
Author(s):  
Benoît RUOT ◽  
Fabienne BÉCHEREAU ◽  
Gérard BAYLE ◽  
Denis BREUILLÉ ◽  
Christiane OBLED
Keyword(s):  
Food Intake ◽  
Food Restriction ◽  
Specific Effect ◽  
Synthesis Rate ◽  
Albumin Concentration ◽  
Mrna Levels ◽  
Albumin Synthesis ◽  
Acute Response ◽  
Absolute Synthesis ◽  
Albumin Mrna

To discriminate between the effects of infection and of anorexia associated with infection, liver albumin synthesis was measured in well-fed rats, in rats injected with live Escherichia coli and in pair-fed rats at different stages of the inflammatory response (1, 6 and 10 days after infection) using a large dose of l-[1-14C]valine. Albuminaemia and albumin mRNA levels were unchanged following food restriction. However, absolute albumin synthesis was decreased in pair-fed rats compared with control animals after 1 day of food restriction, and had returned to normal values by day 10 when food intake was restored. Infection was characterized by a decrease in the plasma albumin concentration (35%, 45% and 28% as compared with pair-fed rats at 1, 6 and 10 days after infection respectively). Albumin mRNA levels and relative albumin synthesis were reduced in infected rats as compared with both control and pair-fed animals at all stages of infection. However, during the early acute response, the albumin absolute synthesis rate was similar in infected rats and pair-fed rats, indicating no specific effect of infection at this stage. Later in the course of infection, the amount of albumin synthesized by the liver was lower in infected than in pair-fed rats, and hypoalbuminaemia was probably maintained due to a lack of stimulation of synthesis despite increased food intake.

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.

scholarly journals Biological basis of hypoalbuminemia in ESRD.

1998 ◽  
Vol 9 (12) ◽  
pp. 2368-2376 ◽  
Author(s):  
G A Kaysen
Keyword(s):  
Peritoneal Dialysis ◽  
Acute Phase ◽  
Synthesis Rate ◽  
Albumin Concentration ◽  
Albumin Synthesis ◽  
Dialysis Patients ◽  
Extravascular Space ◽  
Amyloid A ◽  
Stage Renal Disease ◽  
End Stage

Hypoalbuminemia is associated with mortality in patients with end-stage renal disease (ESRD) maintained either on peritoneal dialysis (PD) or hemodialysis (HD). Serum albumin concentration is determined by its rate of synthesis, by the catabolic rate constant (the fraction of the vascular pool catabolized per unit time), by external losses, and by redistribution from the vascular to the extravascular space. Hypoalbuminemia in dialysis patients is primarily a consequence of reduced albumin synthesis rate in both HD and PD patients, and in the case of PD patents, of transperitoneal albumin losses as well. Continuous ambulatory peritoneal dialysis patients are able to increase albumin synthesis to replace losses. Thus, ESRD does not directly suppress albumin synthesis. The rate of albumin synthesis is inversely proportional to the serum concentration of one potential acute phase protein (alpha2 macroglobulin), and albumin concentration is inversely proportional to that of either C-reactive protein or serum amyloid A in both HD and PD patients. The cause of decreased albumin synthesis is primarily a response to inflammation (the acute phase response), although it is possible that inadequate nutrition may also contribute. The cause of the inflammatory response is not immediately evident. There is no evidence that shifts of albumin to the extravascular space or that dilution of the plasma by volume expansion plays any role in causing hypoalbuminemia in ESRD patients.

Albumin synthesis in humans increases immediately following the administration of endotoxin

2002 ◽  
Vol 103 (5) ◽  
pp. 525-531 ◽  
Author(s):  
Hans BARLE ◽  
Anna JANUSZKIEWICZ ◽  
Lars HÅLLSTRÖM ◽  
Pia ESSÉN ◽  
Margaret A. MCNURLAN ◽  
...  
Keyword(s):  
Intravenous Injection ◽  
Early Phase ◽  
The Other ◽  
Synthesis Rate ◽  
Control Group ◽  
Albumin Synthesis ◽  
Fractional Synthesis Rate ◽  
Before And After ◽  
Fractional Synthesis ◽  
Absolute Synthesis

In order to investigate the immediate (i.e. within 3h) response of albumin synthesis to the administration of endotoxin, as a model of a moderate and well controlled catabolic insult, two measurements employing L-[2H5]phenylalanine were performed in 16 volunteers. One group (n = 8) received an intravenous injection of endotoxin (4ng/kg; lot EC-6) immediately after the first measurement of albumin synthesis, whereas the other group received saline. A second measurement was initiated 1h later. In the endotoxin group, the fractional synthesis rate of albumin was 6.9±0.6%/day (mean±S.D.) in the first measurement. In the second measurement, a significant increase was observed (9.6±1.2%/day; P<0.001). The corresponding values in the control group were were 6.6±0.6%/day and 7.0±0.6%/day respectively (not significant compared with first measurement and P<0.001 compared with the second measurement in the endotoxin group). The absolute synthesis rates of albumin were 148±35 and 201±49mg·kg-1·day-1 before and after endotoxin (P<0.01). In the control group, the corresponding values were 131±21 and 132±20mg·kg-1·day-1 (not significant compared with the first measurement and P<0.01 compared with the second measurement in the endotoxin group). In conclusion, these results indicate that albumin synthesis increases in the very early phase after a catabolic insult, as represented by the administration of endotoxin.

Additive effects of lactation and food restriction to increase hypothalamic neuropeptide Y mRNA in rats

1997 ◽  
Vol 152 (3) ◽  
pp. 365-369 ◽  
Author(s):  
J P H Wilding ◽  
M O Ajala ◽  
P D Lambert ◽  
S R Bloom
Keyword(s):  
Food Intake ◽  
Neuropeptide Y ◽  
Food Restriction ◽  
Mrna Levels ◽  
Additive Effects ◽  
Daily Food Intake ◽  
Glucose Levels ◽  
Daily Food ◽  
Pregnancy And Lactation ◽  
Effect Of Food

Neuropeptide Y (NPY) is the most powerful appetite stimulant known, and rates of synthesis and release in the hypothalamus correlate closely with nutritional status. Pregnancy and lactation provide an excellent model of physiological hyperphagia. In this study the authors measured food intake, plasma glucose, insulin and luteinizing hormone (LH) and hypothalamic NPY mRNA in rats during pregnancy and in early and late lactation. The effect of food restriction (to 80% of control) during lactation was also studied. Pregnancy resulted in a modest increase in daily food intake over non-lactating controls (controls: 15·6±0·6 g, pregnant: 19·8±1·1 g, P<0·01) During lactation food intake increased dramatically to 355% of non-lactating levels by the 12th day. Insulin and glucose levels were unchanged in lactation, except in the food-restricted animals, when insulin levels were reduced to 49·5±18·4 pmol/l compared with 215±55 pmol/l (P<0·01) in lactating, non-restricted animals, and glucose was reduced to 3·7±0·2 mmol/l compared with 5·1 ± 0·2 mmol/l in non-restricted lactating animals. Hypothalamic NPY mRNA was unchanged in pregnancy, moderately increased after 5 days lactation (130±6·2% of control, P<0·01) and increased further at 14 days lactation (179 ± 14%, P<0·001). The greatest changes occurred in the animals who were food-deprived during lactation, when hypothalamic NPY mRNA levels reached 324 ± 44% (P<0·001) of non-lactating levels. Increases in hypothalamic NPY synthesis may be partly responsible for the increase in food intake seen in lactation, but unlike in food deprivation, the increase is not related to circulating insulin, suggesting involvement of other regulatory factors. Journal of Endocrinology (1997) 152, 365–369

scholarly journals Gonadotropin-Releasing Hormone-II Messenger Ribonucleic Acid and Protein Content in the Mammalian Brain Are Modulated by Food Intake

Endocrinology ◽  
2006 ◽  
Vol 147 (11) ◽  
pp. 5069-5077 ◽  
Author(s):  
Alexander S. Kauffman ◽  
Karolina Bojkowska ◽  
Aileen Wills ◽  
Emilie F. Rissman
Keyword(s):  
Food Intake ◽  
Food Restriction ◽  
Mammalian Brain ◽  
Mrna Levels ◽  
Female Reproduction ◽  
Messenger Ribonucleic Acid ◽  
Medial Habenula ◽  
Sufficient Energy ◽  
Peptide Family ◽  
Ad Libitum

GnRH-II is the most evolutionarily conserved member of the GnRH peptide family. In mammals, GnRH-II has been shown to regulate reproductive and feeding behaviors. In female musk shrews, GnRH-II treatment increases mating behaviors and decreases food intake. Although GnRH-II-containing neurons are known to reside in the midbrain, the neural sites of GnRH-II action are undetermined, as is the degree to which GnRH-II is regulated by energy availability. To determine whether GnRH-II function is affected by changes in food intake, we analyzed the levels of GnRH-II mRNA in the midbrain and GnRH-II protein in numerous target regions. Adult musk shrews were ad libitum fed, food restricted, or food restricted and refed for varying durations. Compared with ad libitum levels, food restriction decreased, and 90 min of refeeding reinstated, GnRH-II mRNA levels in midbrain and GnRH-II peptide in several target areas including the medial habenula and ventromedial nucleus. Refeeding for 90 min also reinstated female sexual behavior in underfed shrews. In male shrews, abundant GnRH-II peptide was present in all sites assayed, including the preoptic area, a region with only low GnRH-II in females. In contrast to females, food restriction did not affect GnRH-II protein in male brains or inhibit their mating behavior. Our results further define the relationship between GnRH-II, energy balance, and reproduction, and suggest that food restriction may inhibit female reproduction by reducing GnRH-II output to several brain nuclei. We postulate that this highly conserved neuropeptide functions similarly in other mammals, including humans, to fine-tune reproductive efforts with periods of sufficient energy resources.

Chronic food restriction and acute food deprivation decrease mRNA levels of opioid peptides in arcuate nucleus

1996 ◽  
Vol 270 (5) ◽  
pp. R1019-R1024 ◽  
Author(s):  
E. M. Kim ◽  
C. C. Welch ◽  
M. K. Grace ◽  
C. J. Billington ◽  
A. S. Levine
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Food Deprivation ◽  
Food Restriction ◽  
Arcuate Nucleus ◽  
Mrna Levels ◽  
Endogenous Opioid ◽  
Pomc Mrna ◽  
Opioid Administration ◽  
Ad Libitum Intake

Although opioid administration induces food intake, the relationship between endogenous opioid synthesis and food consumption is unclear. Two studies examined the effects of food restriction and deprivation on opioid mRNA levels in the arcuate nucleus (ARC) of the rat. Body weight significantly decreased following food restriction and deprivation (P < 0.0001). In experiment 1, food restriction of 10,20,30, and 40% (g) of ad libitum intake for 14 days decreased proDynorphin (proDyn), proEnkephalin (proEnk), and proOpiomelanocortin (POMC) mRNA levels in a linear fashion relative to changes in body weight (r = 0.398, P = 0.0011; r = 0.455, P = 0.0028; r = 0.292, P = 0.0642, respectively). In experiment 2, 48 h deprivation significantly decreased mRNA levels of proDyn and POMC by 23.7% (P < 0.05) and 45.6% (P < 0.01), respectively, whereas 24 h food deprivation decreased POMC mRNA by 43.% (P < 0.01). proEnk mRNA was not affected by 24- or 48-h food deprivation. Restricting food intake suppressed mRNA levels of proDyn, proEnk, and POMC by 29.7, 22.3, and 44.4%, respectively, in 20% restricted rats and by 35.5, 26.8, and 45.6%, respectively, in 40%restricted rats (P < 0.01). It appears that ARC mRNA levels of proDyn, proEnk, and POMC are directly related to the amount of food consumed and/or changes in body weight in food-restricted and food-deprived rats.

Changes in plasma albumin concentration, synthesis rate, and mRNA level during acute inflammation

1986 ◽  
Vol 251 (6) ◽  
pp. C928-C934 ◽  
Author(s):  
W. S. Liao ◽  
L. S. Jefferson ◽  
J. M. Taylor
Keyword(s):  
Inflammatory Response ◽  
Total Protein ◽  
Plasma Proteins ◽  
Acute Inflammation ◽  
Mrna Level ◽  
Control Level ◽  
Synthesis Rate ◽  
Relative Reduction ◽  
Albumin Concentration ◽  
Albumin Mrna

Induction of acute inflammation in rats by the subcutaneous injection of turpentine resulted in a marked fall in the concentration of albumin in plasma. This fall, which reached a minimum of 45% of the control level at 36 h after injection of the inflammatory agent, occurred in the presence of no significant change in the concentration of total protein in plasma. It was accompanied by a corresponding decline in the relative abundance of albumin mRNA in liver, which reached a minimum of 25% of the control level at 36 h after initiation of the inflammatory response. Perfused livers from 36-h postinjection rats exhibited albumin secretion rates that were reduced to 38% of control values. In contrast, release of total secretory proteins, secretion of nonalbumin plasma proteins, and synthesis of nonexported proteins by perfused livers were elevated to 166, 266, and 117% of the control values, respectively, as a result of the inflammatory response. These results demonstrate that acute inflammation causes a relative reduction in hepatic albumin mRNA, which leads to a corresponding decrease in albumin synthesis and secretion by liver and a fall in the concentration of albumin in plasma. The concentration of total protein in plasma is maintained during acute inflammation in part by increased synthesis and secretion by liver of nonalbumin plasma proteins, e.g. the acute-phase reactants.

Diet-induced changes in gene expression of lactase in rat jejunum

1995 ◽  
Vol 268 (6) ◽  
pp. G1066-G1073 ◽  
Author(s):  
T. Goda ◽  
H. Yasutake ◽  
Y. Suzuki ◽  
S. Takase ◽  
O. Koldovsky
Keyword(s):  
Gene Expression ◽  
Corn Oil ◽  
Unit Weight ◽  
Synthesis Rate ◽  
Mrna Levels ◽  
Lactase Activity ◽  
High Starch ◽  
The Absolute ◽  
Absolute Synthesis ◽  
Starch Diet

To explore the mechanisms by which jejunal lactase activity is modified by carbohydrate and/or fat intake, mRNA levels and the absolute synthesis rate of lactase-phlorizin hydrolase (LPH) were determined in 6-wk-old rats that were fed either low-starch diets containing long-chain triacylglycerol (LCT, 73% energy as corn oil) or medium-chain triacylglycerol (MCT, 66% energy as MCT, 7% energy as corn oil), or a high-starch diet (70% energy as cornstarch) for 7 days. LPH mRNA levels in the jejunum were similar between LCT-fed and MCT-fed rats, but animals fed the high-starch diet exhibited a greater (2x) LPH mRNA level than other groups. The absolute synthesis rate of LPH, estimated by the flooding dose technique using [3H]phenylalanine, was greater (2.4x) in rats fed the high-starch diet than in other groups. A short-term force-feeding experiment revealed that sucrose was able to evoke LPH mRNA levels within 12 h but that a nonmetabolizable sugar (alpha-methylglucoside) was unable to enhance it. By contrast, animals fed the high-LCT diet showed a lower (by 30%) lactase activity than rats fed the low-starch, high-MCT diet, which was accompanied by not only a reduction of immunoreactive LPH in brush-border membranes but also a reduction in lactase activity per unit weight of immunoreactive LPH. These results suggest that both gene expression and posttranslational events of LPH might be influenced by dietary manipulations; carbohydrate intake primarily increases LPH mRNA levels, and LCT accelerates inactivation and/or degradation of lactase.

Liver export protein synthetic rates are increased by oral meal feeding in weight-losing cancer patients

2000 ◽  
Vol 279 (3) ◽  
pp. E707-E714 ◽  
Author(s):  
Matthew D. Barber ◽  
Kenneth C. H. Fearon ◽  
Donald C. McMillan ◽  
Christine Slater ◽  
James A. Ross ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Synthesis Rate ◽  
Similar Degree ◽  
Albumin Concentration ◽  
Fibrinogen Concentration ◽  
Albumin Synthesis ◽  
Fed State ◽  
Synthetic Rate ◽  
Export Protein ◽  
Median Weight Loss

We have demonstrated previously that, in the fasting state, whereas albumin synthesis is similar in cachectic cancer patients compared with controls, fibrinogen synthesis is increased. Whether synthesis of these proteins is altered after an oral meal was examined in eight weight-losing pancreatic cancer patients and six healthy controls by use of an intravenous flooding dose of [2H5]- or [2H8]phenylalanine. Cancer patients had a median weight loss of 19%, a significantly lower serum albumin concentration, and a significantly higher plasma fibrinogen concentration than controls ( P < 0.005). Fasting albumin synthesis rates were similar between cancer patients and controls (median total synthesis rate 11.3 vs. 13.9 g/day, respectively) and rose on feeding by a similar degree (median 29 and 24%). The fasting fibrinogen total synthetic rate was significantly higher in cancer patients than in controls (median 3.3 vs. 1.0 g/day, P = 0.0019). In cancer patients in the fed state, fibrinogen synthetic rate rose by a median of 38% ( P = 0.012), whereas in controls there was no significant change. These findings demonstrate significant upregulation by feeding of acute-phase protein synthesis in cachectic cancer patients.

Measurement of albumin synthesis in humans: a new approach employing stable isotopes

1990 ◽  
Vol 259 (6) ◽  
pp. E797-E803 ◽  
Author(s):  
P. E. Ballmer ◽  
M. A. McNurlan ◽  
E. Milne ◽  
S. D. Heys ◽  
V. Buchan ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Stable Isotopes ◽  
Isotope Ratio Mass Spectrometry ◽  
Gas Chromatography Mass Spectrometry ◽  
Synthesis Rate ◽  
Albumin Synthesis ◽  
Time Curve ◽  
Fractional Synthesis ◽  
Clinical Conditions ◽  
Absolute Synthesis

A new method for measuring albumin synthesis in humans with stable isotopes is presented. This can readily be applied in most clinical conditions, even when albumin losses are occurring or when repeated assessment is required. After rapid intravenous injection of a large dose of [13C]leucine (57 mg/kg body wt, 19.4 atoms%), plasma samples were taken at intervals up to 90 min. The enrichment of free leucine in plasma measured by gas chromatography-mass spectrometry rose to a peak at 10 min and then fell slowly, whereas that in liver biopsies (from surgical patients) ranged from 101.5 to 80.5% of the plasma value between 10 and 90 min after injection. The fractional synthesis rate (FSR) was calculated by dividing the increase in enrichment of leucine in albumin, measured by gas isotope ratio mass spectrometry, by the area under the plasma free leucine enrichment vs. time curve after allowing for the period between synthesis of the protein and its secretion into the plasma. The FSR in healthy postabsorptive males was 7.2 +/- 1.3%/day, and the absolute synthesis rate was 157 +/- 39 mg.kg body wt-1.day-1. These rates are comparable to those obtained by other methods.

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