Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Protein Deficiency”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

Effect of iron and protein deficiency on the expulsion of Nippostrongylus brasiliensis from the small intestine of the rat.

The relationship between iron deficiency and protein deficiency and infestation of the rat with the nematode Nippostrongylus brasiliensis was investigated. There was a significant delay in the expulsion of N. brasiliensis from the small intestine of both iron deficient and protein deficient animals and those with a combined deficiency of iron and protein. Iron repletion returned the time of worm expulsion to normal and this would appear to be related to iron deficiency per se rather than to anaemia. Antibody initiated damage to worms was normal in the control animals and in animals with nutritional deficiencies. This suggests that the defect in worm expulsion occurs either in the cell-mediated immune system or in one of the other mediators of expulsion. Extrapolation to the human situation has important therapeutic implications in that iron and protein deficiency may play an important role in the perpetuation of helminth infestations. Thus, to be successful antihelminth therapy should be accompanied by iron and protein supplementation.

Ancylostomatoidea↗

Effects of protein deficiency on muscle myofibrillar protein turnover in adult rats.

The rates of gain, catabolism, synthesis and reutilization of myofibrillar protein were measured in adult rats fed a protein-free diet, low protein diet (2% lactalbumin) or control diet (10% lactalbumin) for 14 to 31 days. Two forms of synthesis were measured: exogenous synthesis (nitrogen derived from diet) and endogenous synthesis (nitrogen derived from catabolized body protein). The rate of gain of myofibrillar protein was measured as the rate of increase in its weight and the rate of catabolism was determined from urinary 3-methylhistidine excretion. The rate of total synthesis was calculated as the sum of these two rates. Exogenous synthesis was calculated from the recovery of isotope in protein 24 h after oral administration of 15N-leucine and endogenous synthesis was calculated as the difference between the total synthesis and exogenous synthesis. Reutilization was calculated as the ratio of endogeneous synthesis to catabolism. The rate of catabolism was slightly decreased in protein deficiency (2.1, 2.1 and 2.6% in the protein-free, low protein and control groups, respectively), while that of synthesis was significantly decreased in protein deficiency (1.3, 2.0 and 3.3% in the respective groups). Restriction of protein intake resulted in a decrease in the rate of exogenous synthesis, without appreciable change of endogenous synthesis. The reutilization rate of endogenous N was estimated to be about 70% in rats with restricted protein intakes and about 50% in those with a normal protein intake.

Animals↗

Pharmacokinetics, metabolism and disposition of salicylate in protein-deficient rats.

The influence of dietary protein deficiency on the pharmacokinetics, metabolism, and disposition of sodium salicylate was investigated in Sprague-Dawley male rats. Animals were fed for 3 weeks a 21% (control) or a 5% (deficient) protein diet ad lib.; an additional group of rats (pair-fed controls) was fed for 3 weeks the control 21% protein diet in a restricted quantity (10 g/day/rat), which was approximately equal to the quantity (9.8 g/day) consumed by rats receiving the 5% protein diet ad lib. Sodium salicylate (in salicyclic acid equivalents) and its metabolites were assayed by HPLC. In both control and protein-deficient rats, sodium salicylate kinetics were dose-dependent and the decline in its plasma concentration proceeded according to a first-order process; no differences in the two groups of animals were found with respect to the following features of the biological fate of salicylate: plasma half-life and clearance at a 2-mg/kg (iv) dose level, volume of distribution at all dose levels (2, 10, and 100 mg/kg, iv), relative bioavailability by oral route, tissue distribution, and the rate of urinary excretion of salicyl glucuronides at 10-mg/kg dose level. However, at high dose levels (10 and 100 mg/kg, iv), the plasma half-life of salicylate was shorter and its clearance greater in protein-deficient than in control rats. The following additional changes were caused by dietary protein deficiency: a decrease in salicylate binding to serum protein, an increase in the metabolic transformation of salicylic acid to its glycine conjugate, salicyluric acid, by kidney mitochondrial preparations, an increase in the urinary excretion of salicyluric acid and salicylic acid, and a decrease in the elimination half-life of salicylic acid; the excretion of salicyluric acid proceeded according to a first-order process in protein-deficient rats but according to an apparent zero-order process in the controls. The changes in the plasma half-life and clearance of salicylate in pair-fed controls were not significant; it appears that a deficiency of both proteins and calories (protein-deficient rats) exerts greater influence on the biological fate of salicylate than does a deficiency mainly of calories (pair-fed controls). It is suggested that the decrease in the plasma half-life of salicylate in protein-deficient rats is the result of an increase in its clearance, which in turn is caused by a decrease in protein-salicylate binding and an increase in the metabolism of salicylic acid to salicyluric acid. These results point to the desirability of a systematic study of the biological fate of salicylate during clinical malnutrition, which is common in developing countries.

Animals↗

The effect of diuretics on the water excretion of protein deficient rats.

Adult rats kept for eleven weeks on a diet deficient in protein lost weight and some developed scrotal oedema. The retention of bromsulphthalein was increased, but the thymol turbidity test was unaffected; the apparent plasma volume was increased.Water diuresis in the protein deficient animals was impaired. There was no apparent delay in the mean rate of water absorption from the whole gastro-intestinal tract although a delayed absorption of water from the intestine was found in some animals. The concentrations of total plasma proteins and plasma albumin were low as compared with normal animals, but the plasma sodium levels were within normal limits. The inulin clearance (glomerular filtration rate) of the animals on the protein-deficient diet was significantly lower than that of the controls.In normal rats, aminophylline and acetazolamide were diuretic. Caffeine and sodium benzoate did not increase the urine output and mersalyl was antidiuretic. In the protein deficient rats, cortisone acetate increased the water diuresis. Caffeine and sodium benzoate, aminophylline and acetazolamide did not significantly increase this response, mersalyl had an antidiuretic effect. Cortisone acetate increased the food and water intake of the protein deficient rats; it also increased the glomerular filtration rate.

Animals↗

[Amino acid composition of proteins of the membranes of rat liver sucellular structures and the effect of protein deficiency on it].

The protein amino acids composition of nuclear, mitochondrial and lysosomic membranes and those of the endoplasmatic reticulum of the liver in rats receiving for 30 days rations with normal (18.5 per cent) and low (4 per cent) protein content was investigated. The amino acid spectra of proteins forming part of various cytomembranes, in spite of their considerable resemblance, are shown to have traits of a definite specificity. Protein deficit in the ration causes not only a fall of the total amino acid content in the membranous cellular structures, but it also attended by a deranged correlation among individual amino acids.

Amino Acids↗

Effects of protein deficient diets on the developmental toxicity of inorganic arsenic in mice.

BACKGROUND: Inorganic arsenic, when given by injection to pregnant laboratory animals (mice, rats, hamsters), has been shown to induce malformations. Arsenic methylation may be a detoxification step, and diets deficient in protein are a poor source of methyl donors and may possibly result in impaired arsenic methylation. Human health effects from chronic arsenic exposure have been reported mainly in populations with low socioeconomic status. Individuals in such populations are likely to suffer from malnutrition, which can compromise embryonic/fetal development and diminish arsenic methylating capacity. We sought to determine if dietary protein deficiency affects the developmental toxicity of inorganic arsenic. METHODS: Mated females were randomly assigned to one of 12 treatment groups. Experimental groups received either AsIII or AsV i.p. on Gestation Day 8 (GD 8, plug=GD 0) and were maintained on a 5%, 10%, or 20% protein custom mixed diet from GD 1 until sacrifice. Controls received the custom diets alone, were given AsIII or AsV i.p. on GD 8 with Teklad LM-485 rodent diet, or were fed the LM-485 diet alone. Test females were sacrificed on GD 17, and their litters were examined for mortality and developmental defects. RESULTS: Arsenic plus dietary protein deficiency decreased maternal weight gain and increased the incidences of exencephaly, ablepharia, and skeletal defects, such as malformed vertebral centra, fused ribs, and abnormal sternebrae (bipartite, rudimentary, or unossified). CONCLUSIONS: These results demonstrate that dietary protein deficiency enhances the developmental toxicity of inorganic arsenic, possibly by impairment of arsenic methylation.

Abnormalities, Drug-Induced↗

Chronic protein deficiency differentially affects the kinetics of plasma proteins in young pigs.

The use of plasma protein concentrations to assess protein-nutritional status has been questioned because concentrations and kinetics are affected by factors other than protein intake. To determine the effect of protein deficiency on plasma protein concentration and synthesis, two groups of four piglets consumed diets containing either 20 or 3% protein. After 8 wk, 2H3-leucine was infused intravenously to measure the fractional and absolute synthesis rates (FSR and ASR) of albumin, transferrin, retinol binding protein (RBP), transthyretin (TTR), a new peptide called TTR2, the high density apolipoprotein (HDL-apoA-1), fibrinogen, and haptoglobin. Compared with controls, protein-deficient pigs had significantly lower (P < 0.05) plasma albumin, RBP and TTR2 concentrations, significantly slower (P < 0.05) FSR of fibrinogen, HDL-apoA-1, transferring and TTR2, significantly lower (P < 0.05) ASR of albumin, fibrinogen, transferrin, and TTR2, and a significantly higher (P < 0.05) ASR of TTR. Fibrinogen and transferrin concentrations did not differ between groups, but transthyretin concentration was higher in protein-deficient pigs. These results suggest that protein-nutritional status cannot be predicted from the concentrations of all plasma proteins, that chronic protein deficiency affects the rate of synthesis of only some plasma proteins, and that the kinetic response of plasma proteins to protein restriction cannot be predicted from measurements of plasma concentrations.

Aging↗

alpha-1-Antitrypsin metabolism in the protein-deficient weanling rat.

Protein-deficient weanling rats fed on a 30 g casein/kg diet for 3 weeks lost albumin but maintained the level of serum alpha-1-antitrypsin, the most abundant protease inhibitor in blood. alpha-1-Antitrypsins from malnourished rats and control rats (given 250 g casein/kg diet) differed; the protease inhibitor from protein-deficient animals: (1) was more acidic, (2) appeared slightly larger (57 400 v. 56 000 daltons) on sodium dodecyl sulphate (SDS)-polyacrylamide gels, (3) had a more acidic Pi type and increased anodal mobility at pH 8.9, (4) bound more concanavalin-A and contained more carbohydrate, specifically two to three extra sialic acid residues. The amino sugar and neutral sugar contents of both preparations of alpha-1-antitrypsin were the same. Analysis of the products of cyanogen-bromide cleavage revealed that alpha-1-antitrypsin preparations from protein-deficient rats contain an extra glycopeptide that was not present in alpha-1-antitrypsin from control animals. In vivo studies showed that the increased sialic acid content of alpha-1-antitrypsin of protein-deficient rats did not alter the half-life of the molecule in the blood of control rats. However, the fractional catabolic rate of alpha-1-antitrypsin from either well-nourished or protein-deficient rats was significantly (P less than 0.01) lower in protein-deficient rats than in control rats (0.0247/h v. 0.0406/h). The decreased fractional catabolic rate could not be explained by changes in hepatic mannosyl-, galactosyl- or N-acetylhexosaminyl receptors since liver perfusion studies showed that bovine serum albumin, when covalently modified separately with each of these ligands, was extracted from the perfusion medium as rapidly or more rapidly by livers from malnourished animals. Perfused livers from protein-deficient rats secrete three times more alpha-1-antitrypsin than do livers from well-nourished animals. The decreased fractional catabolic rate and increased rate of biosynthesis and secretion of the glycoprotein by livers from protein-deficient animals may account for the maintenance of alpha-1-antitrypsin levels during protein malnutrition.

Albumins↗

Effect of cross-fostering rats at birth on the normal supply of essential fatty acids during protein deficiency.

The effect of protein deficiency on the activity of delta 6 desaturase in the mother during lactation was determined in the liver microsomal fraction and the fatty acid composition of milk lipids from the analyzed stomach contents. The activity of delta 6 desaturase was profoundly affected by protein deprivation during pregnancy and only reached the values of controls at about 10 days after parturition. This fact did not affect the fatty acid pattern of milk lipids and no significant differences in the contents of arachidonic acid were detected between the two groups. Nevertheless, protein deficiency apparently affected milk production. The effects of protein deprivation on the supply of polyenoic acids of cross-fostering rats at birth from protein-deficient to protein-sufficient diets and vice versa, and rats maintained during pregnancy and lactation on a low protein or control diet were examined. The fatty acid pattern of liver phospholipids of the four groups under study was determined and used as a biochemical parameter for evaluating polyenoic acid status. Protein deficiency markedly affected the fatty acid pattern of liver phospholipids. A significant decrease of both arachidonic and docosahexaenoic acids was observed. This fatty acid pattern was reversed when protein-deficient animals were placed on the control diet at birth. On the other hand, the fatty acid composition of controls was negatively affected by cross-fostering to a deficient diet. The findings from the present experiment provide evidence that the negative effect of protein malnutrition appears to be promoted at least in part, by the effect of protein depletion on the supply of polyenoic acids for normal development and metabolic adaptations.

Animals↗

Thyroid function, energy balance, body composition and organ growth in protein-deficient chicks.

Protein-deficient diets (17, 10, 6.5 or 3% protein) and a 24% control diet were fed to growing chicks. A control group was pair-fed daily with each deficient group. Energy intake was lower in the 6.5 and 3% protein groups than in the other groups. However, weight gain, bone growth and feed conversion efficiency were lower with 10% protein or less. Relative thyroid weights were unaffected by dietary protein. Plasma T3 (3,5,3'-triiodothyronine) levels were significantly higher in all deficient groups, whereas plasma T4 (thyroxine) was lower. Plasma rT3 (reverse T3) was unaffected by the protein deficiencies, suggesting that enhanced conversion of T4 to T3 rather than to rT3 had occurred. Hepatic alpha-glycerol-3-phosphate dehydrogenase (alpha-GP) shuttle activity increased markedly in protein-deficient chicks. Efficiency of energy utilization was unaltered in chicks fed 17 or 10% protein but was higher in chicks fed 6.5 and 3% protein than in controls. All deficient chicks had more fat and less protein and water in the tissues. The lower feed conversion efficiency therefore represents almost entirely a shift in body composition toward fat and does not reflect a loss of energy as heat. We conclude that elevations in plasma T3 and in thyroid-controlled alpha-GP shuttle activity, although sensitive indicators of protein deficiencies, are not good predictors of altered thermogenic activity in protein-deficient chicks.

Animals↗

Interaction of galactose and dietary protein deficiency on rat lens.

Protein deficiency, a frequently encountered nutritional disorder of developing countries is known to affect the proliferative and synthetic activities of several cell systems. But neither all the organs are affected at the same time nor at the same rate. The lens, which is an unique organ has been shown to suffer in protein malnutrition but without any clinically discernible changes. Clinical evidence suggests, early onset of senile cataract in underdeveloped countries is possibly due to protein deficiency. In the present investigation, it has been shown that addition of small concentrations of galactose to the diet readily induces cataracts in protein-deficient rats. This therefore supports the contention that protein deficiency alone may not produce morphological changes but exogenous or endogenous cataractogenic insults, may produce lenticular opacification in the protein-deficient state.

Animals↗