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PubMedDate not supplied

[Effect of calciferol-protein deficiency on the metabolism of bone collagen].

Growing rats received rations with separate and combined deficiencies of vitamin D, protein and certain essential amino acids, during 60 days. An increment was recorded in the total amount of collagen in the tubular bones at the expense of its mature, insoluble fraction, in the presence of a decreased content of salt- and acid-soluble fractions of this protein. These shifts were more manifest in combined calciferol-protein deficiency. Disorders in the correlation of collagen biosynthesis, maturation and degradation processes were responsible for these shifts, which was confirmed by the corresponding changes in the rate of 4C-glycine-1 build up in proteins of the bone tissue organic matrix and in the intensity of hydroxyproline urinary excretion.

Animals↗
PubMed2004

Restoration of insulin secretion in pancreatic islets of protein-deficient rats by reduced expression of insulin receptor substrate (IRS)-1 and IRS-2.

Autocrine and paracrine insulin signaling may participate in the fine control of insulin secretion. In the present study, tissue distribution and protein amounts of the insulin receptor and its major substrates, insulin receptor substrate (IRS)-1 and IRS-2, were evaluated in a model of impaired glucose-induced insulin secretion, the protein-deficient rat. Immunoblot and RT-PCR studies showed that the insulin receptor and IRS-2 expression are increased, whilst IRS-1 protein and mRNA contents are decreased in pancreatic islets of protein-deficient rats. Immunohistochemical studies revealed that the insulin receptor and IRS-1 and -2 are present in the great majority of islet cells; however, the greatest staining was localized at the periphery, suggesting a co-localization with non-insulin-secreting cells. Exogenous insulin stimulation of isolated islets promoted higher insulin receptor and IRS-1 and -2 tyrosine phosphorylation in islets from protein-deficient rats, as compared with controls. Moreover, insulin-induced IRS-1- and IRS-2-associated phosphatidylinositol 3-kinase activity are increased in islets of protein-deficient rats. The reduction of IRS-1 and IRS-2 protein expression in islets isolated from protein-deficient rats by the use of antisense IRS-1 or IRS-2 phosphorthioate-modified oligonucleotides partially restored glucose-induced insulin secretion. Thus, the impairment of insulin cell signaling through members of the IRS family of proteins in isolated rat pancreatic islets improves glucose-induced insulin secretion. The present data reinforced the role of insulin paracrine and autocrine signaling in the control of its own secretion.

Animals↗
PubMed2005

Effect of protein deficiency on macroelement and trace element levels of weanling rats' small intestine and liver tissues.

Protein energy malnutrition has become a major health issue in developing countries. In the present study, the effect of protein deficiency on the small intestine and liver tissue content of macroelements and trace elements was investigated in weanling rats. Forty-five male weanling Wistar albino rats were divided into three groups. The control group (C) was fed a standard diet containing 25% casein, whereas the two experimental groups E1 and E2 consumed 12% and 3% casein, respectively, over a period of 45 d. The tissue samples were analyzed for zinc, copper, iron, manganese, calcium, and magnesium by atomic absorption spectroscopy. The protein-deficient groups showed increased levels of iron in both tissues and decreased manganese in small intestine tissue from the E1 group. No other differences were found for the other elements. These results suggest that protein deficiency might cause iron accumulation in the liver and intestine and decreases of manganese in the small intestine.

Animals↗
PubMed1995

Effects of ethanol and protein deficiency on pancreatic digestive and lysosomal enzymes.

The pathogenesis of alcoholic pancreatitis is not fully understood. An increase in pancreatic digestive and lysosomal enzyme synthesis because of ethanol consumption could contribute to the development of pancreatic injury in alcoholics. This study aimed, firstly, to determine the effect of ethanol on the content and messenger RNA levels of pancreatic digestive enzymes and on the messenger RNA level of the lysosomal enzyme cathepsin B, and secondly, to examine the influence of concomitant protein deficiency (a known association of alcoholism and pancreatic injury) on these effects. A rat model of chronic ethanol administration was used in which rats were fed in groups of four, and for four weeks, protein sufficient and protein deficient diets with or without ethanol. Ethanol increased the pancreatic content of lipase but did not influence chymotrypsinogen or trypsinogen values. mRNA levels for lipase, trypsinogen, and chymotrypsinogen were raised in rats fed ethanol. Protein deficiency resulted in reduced tissue levels of lipase, chymotrypsinogen, and amylase but did not influence trypsinogen values. mRNA levels for proteases were increased in protein deficient rats, while those for lipase remained unaltered. Both ethanol and protein deficiency increased mRNA levels for cathepsin B. It is concluded that chronic ethanol consumption, in both protein sufficient and protein deficient states, increases the capacity of the pancreatic acinar cell to synthesise digestive and lysosomal enzymes.

Amylases↗
PubMed1998

Protein deficiency induces alterations in the distribution of T-cell subsets in experimental pulmonary tuberculosis.

Previous research has suggested that dietary protein deficiency alters resistance to experimental pulmonary tuberculosis, in part, by affecting the distribution and trafficking of antigen-reactive T cells. In this study, guinea pigs were maintained on either a protein-deficient (10% ovalbumin) or control (30% ovalbumin) diet and infected 4 to 6 weeks later with a low dose of virulent Mycobacterium tuberculosis H37Rv by the respiratory route. Monoclonal antibodies directed against the CD4 or CD8 markers on guinea pig lymphocytes were used in a flow cytofluorometric assay to determine the proportion of each subset in the peripheral circulation, spleen, and bronchotracheal lymph nodes at 4 weeks after infection. In uninfected guinea pigs, only the spleen exhibited an effect of diet on T-cell distribution, with small but consistent reductions in the proportions of both CD4 and CD8 T lymphocytes. However, following infection, protein deficiency exerted a profound effect on T-cell distribution. Malnourished, tuberculous guinea pigs harbored only 20 and 60% of the T cells (as a proportion of total lymphoid cells) found in the spleen and blood, respectively, of their well-nourished counterparts. Normal relative proportions of CD4 and CD8 cells were observed, however. In striking contrast, the bronchotracheal lymph nodes of protein-deprived guinea pigs with tuberculosis contained more than twice the numbers of T cells of control guinea pigs, and the normal CD4-to-CD8 ratio was reversed. Peripheral T-cell function, as measured by the delayed hypersensitivity skin test to tuberculin, and antigen-induced lymphoproliferation in vitro were markedly suppressed in protein-malnourished animals. Conversely, purified protein derivative-induced (but not concanavalin A-induced) proliferation was significantly enhanced in cultures of lymph node cells from protein-deprived tuberculous animals. Taken together, these results suggest that immunological abnormalities and loss of antimycobacterial resistance in the lungs of protein-deficient guinea pigs may be explained, in part, by sequestration of antigen-reactive T cells in the lymph nodes draining the site of infection.

Animals↗
PubMed1996

Activation of protease activity in rat peritoneal macrophages in protein deficiency: characterization of cathepsin D.

Rat peritoneal macrophages contained high proteolytic activity that was significantly enhanced under the stress induced by protein deficiency. The aspartyl protease cathepsin D which has been known to be the most active protease in endocytic processes was extracted from the macrophages recovered from control (20% protein fed) and protein deficient (4% protein fed) rats and was affinity purified and characterized further. The cathepsin D from the control sample exhibited better recovery, purification and higher specific activity compared to that from the deficient groups. Apparently the pH optima and heat stability of the enzyme from both the groups were similar. The SDS PAGE profile clearly indicated the presence of greater amounts of active forms of cathepsin D in the deficient samples in vivo itself which reflected in a reduction in Km value of the enzyme. Subtle differences observed in the activity of these macrophage proteases in the protein deficient rats may be partly responsible for the enhanced degradation of macrophage membrane proteins reported earlier.

Animals↗
PubMed1979

The effect of oral pancreatic enzymes on the intestinal flora of protein-deficient vervet monkeys challenged with Vibrio cholerae.

Jejunal bacterial flora in 11 protein deficient vervet monkeys (Cercopithecus aethiops) and four controls was studied. These were the same animals from an investigation previously reported in which it was shown that pancreatic extract modified the course of cholera infection in protein-deficient monkeys. The present study reports in addition that these animals the fluid in the upper jejunum contained significantly increased numbers of bacteria including Enterobacteriaceae compared to its predietary state and to that of the controls. After challenge to these animals with Vibrio cholerae, the jejunal bacterial flora in the protein-deficient animals given placebo remained unchanged, whereas pancreatic extract-treated animals showed a quantitative and qualitative recovery of their jejunal bacterial flora. Pancreatic extract hastened the return of altered intestinal flora to predietary levels.

Animals↗
PubMed1983

The influence of maternal protein deficiency on the placental transfer of salicylate in rats.

1 The influence of a low protein diet (5% as compared with a control 21% protein diet) on the placental transfer of sodium salicylate was investigated in Sprague-Dawley rats on day 20 of gestation. 2 Maternal plasma salicylate concentrations (assayed by high pressure liquid chromatography) were generally lower in protein-deficient than in control animals at a wide range of times (0.25 - 12 h) and dose levels (2 - 250 mg/kg, i.v.); however, foetal plasma salicylate levels in the two groups of animals did not differ. 3 The placental transfer of salicylate as indicated by the ratio of foetal plasma or foetal liver to maternal plasma salicylic acid concentration was consistently and significantly greater in the protein-deficient group than in the control group of animals following the administration of the drug to the mother as well as to the foetus. 4 A decrease in calorie without a concomitant decrease in protein intake (pair-fed controls) did not alter the placental transfer of salicylate. 5 The increased placental transfer of salicylate in protein-deficient animals could not be attributed to changes in serum protein-salicylate binding. 6 It is suggested that the pharmacokinetic factors responsible for maintaining a lower level of salicylate in the foetus than in the mother are impaired by maternal malnutrition, and this may increase the foetal effects of maternally ingested salicylate.

Animals↗
PubMed1991

Changes in macrophage membrane proteins in relation to protein deficiency in rats.

Resident and thioglycollate (TG) macrophages were isolated from rats fed 20 and 4% protein diets. These cells were cultured for 2 and 18 hr; further the membrane proteins were separated by SDSPAGE. Though basically all the samples had a similar banding pattern, the protein profile was very complex in nature. TG elicited macrophages from the protein fed group had increased contents of high molecular weight proteins compared to the resident cells from both the groups as well as TG cells from the protein deficient group. The difference increased with prolonged incubation. Polypeptides at 56.5 and 46 kd which were prominently present in the control samples, was very low in the protein deficient ones. Bands at 34, 32, 27 to 19.5 kd were reduced in the TG cells from the protein fed group. The protein deficient samples exhibited a strong band at 43 kd (presumably actin) while it was present in very small amounts in the cells from the protein fed groups. These observations indicate that the protein restriction had down regulated TG induced modulation of macrophage membrane proteins to the level of resident cells which are physiologically in a lower state of activation. These changes could reflect on their reduced functional properties.

Animals↗
PubMed1998

Maternal dietary protein deficiency decreases amino acid concentrations in fetal plasma and allantoic fluid of pigs.

This study was conducted to test the hypothesis that maternal dietary protein deficiency decreases amino acid availability to the fetus, thereby contributing to retarded fetal growth. Primiparous gilts selected genetically for low or high plasma total cholesterol concentrations (low line and high line, respectively) were mated, and then fed 1.8 kg/d of isocaloric diets containing 13% or 0.5% crude protein. At d 40 or 60 of gestation, they were hysterectomized, and maternal and fetal blood samples as well as amniotic and allantoic fluids were obtained for analyses of amino acids, ammonia and urea. Dietary protein restriction decreased (P < 0.05) the following: 1) maternal plasma concentrations of urea at d 40 and 60 of gestation; 2) fetal plasma concentrations of alanine, arginine, branched-chain amino acids (BCAA), glutamine, glycine, lysine, ornithine, proline, taurine, threonine and urea at d 60 of gestation; 3) amniotic and allantoic fluid concentrations of urea at d 40 and 60 of gestation; and 4) allantoic fluid concentrations of alanine, arginine, BCAA, citrulline, cystine, glycine, histidine, methionine, proline, serine, taurine, threonine and tyrosine at d 40 of gestation, in gilts of both genetic lines. At d 60 of gestation, protein deficiency decreased (P < 0.05) allantoic fluid concentrations of arginine, cystine, glycine, taurine and tyrosine in low line gilts and of cystine, glutamine, ornithine, serine, taurine and tyrosine in high line gilts. Low line and high line gilts also differed remarkably in allantoic fluid concentrations of arginine, glutamine, ornithine and ammonia at d 40 and 60 of gestation. Our results suggest the following: 1) protein-deficient gilts maintain maternal plasma concentrations of amino acids by mobilizing maternal protein stores and decreasing oxidation of amino acids during the first half of gestation; 2) protein deficiency may impair placental transport of amino acids from the maternal to the fetal blood; and 3) low line and high line gilts differ in fetal amino acid metabolism. Decreases in concentrations of the essential and nonessential amino acids in the fetus may be a mechanism whereby maternal dietary protein restriction results in fetal growth retardation.

Allantois↗
PubMed1980

Extracellular accumulation of L-glutamate in adenylyl cyclase deficient or cyclic AMP receptor protein deficient mutants of Escherichia coli.

An Escherichia coli cya mutant deficient in adenylyl cyclase and an E. coli crp mutant deficient in cyclic AMP receptor protein (CRP) accumulate substantial amounts of L-glutamate extracellularly when entering stationary phase of growth. The cya mutant grown in the presence of cyclic AMP accumulates little glutamate whereas the addition of cyclic AMP has no effect on glutamate accumulation in the crp mutant. It is proposed that an E. coli cell entering stationary phase requires a change in cell envelope structure which involes a cyclic AMP-CRP dependent process, and without this process the permeability of the cell membrane increases.

Adenylyl Cyclases↗
PubMedDate not supplied

Growth and reproductive adaptation in male rats with chronic protein deficiency.

In previous studies, male rats fed a low-protein diet beginning at weaning were found to have impaired sexual development through age 11 weeks when compared to food-restricted, weight-matched controls fed a diet with normal protein content. To determine whether male rats show long-term adaptation of the reproductive axis to low-protein feeding, we assessed sexual maturation and growth in rats fed a low protein (9%) diet from weaning until sacrifice at various points in time between ages 79 and 185 days. After age 80 days, there was no difference in reproductive organ weights (prostate, seminal vesicles, testis) or serum hormone levels (luteinizing hormone, follicle stimulating hormone, testosterone) between protein-deficient animals and food-restricted weight-matched controls given a normal diet. In addition, there was no difference between protein-deficient animals and controls in indices of linear growth (naso-anal and tail length) or fatness (Lee index). We conclude that both growth and reproductive function of male rats show adaptation to long term feeding of a low-protein diet.

Adaptation, Biological↗
PubMed1997

D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase bifunctional protein deficiency: a newly identified peroxisomal disorder.

Peroxisomal beta-oxidation proceeds from enoyl-CoA through D-3-hydroxyacyl-CoA to 3-ketoacyl-CoA by the D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxy-acyl-CoA dehydrogenase bifunctional protein (d-bifunctional protein), and the oxidation of bile-acid precursors also has been suggested as being catalyzed by the d-bifunctional protein. Because of the important roles of this protein, we reinvestigated two Japanese patients previously diagnosed as having enoyl-CoA hydratase/L-3-hydroxyacyl-CoA dehydrogenase bifunctional protein (L-bifunctional protein) deficiency, in complementation studies. We found that both the protein and the enzyme activity of the d-bifunctional protein were hardly detectable in these patients but that the active L-bifunctional protein was present. The mRNA level in patient 1 was very low, and, for patient 2, mRNA was of a smaller size. Sequencing analysis of the cDNA revealed a 52-bp deletion in patient 1 and a 237-bp deletion in patient 2. This seems to be the first report of D-bifunctional protein deficiency. Patients previously diagnosed as cases of L-bifunctional protein deficiency probably should be reexamined for a possible d-bifunctional protein deficiency.

17-Hydroxysteroid Dehydrogenases↗
PubMed1992

The effects of protein deficiency and fluoride on bone mineral content of rat tibia.

This study examined the effects of chronic protein deficiency and fluoride administration (10 mg/kg/day), separately or in combination, on rat tibia properties. Protein deficiency increased the bone fluoride concentration and reduced the bone mineral content (BMC) especially at the proximal or growing end which contains mainly cancellous bone. Fluoride administration also reduced BMC, but to a lesser extent, and it resulted in proximal tibia fluoride concentrations that were nearly twice those of the distal tibia. The interaction between fluoride administration and the protein content of the diet on BMC was nonsignificant, suggesting that the effects were additive, not multiplicative or synergistic. Fluoride administration, but not protein deficiency, increased bone magnesium levels. It is hypothesized that the reduction in BMC in the areas where the fluoride concentrations were the highest was due to a localized toxic effect of fluoride.

Absorptiometry, Photon↗
PubMed1982

Effects of starvation and protein deficiency on the acute carbon tetrachloride-induced hepatotoxicity.

The effects of starvation and protein-deficient diet on the acute carbon tetrachloride (CCl4)-induced hepatotoxicity of the mice were studied histologically and histochemically. A total of 69 male mice (C57BL/6) were used and carbon tetrachloride was administered by a single subcutaneous injection at a dose of 0.1 mg/10 g body weight after starvation for 24 hours and feeding with protein-deficient diet for one month. The changes were examined consecutively. It was shown the the CCl4-induced hepatotoxicity was exaggerated by starvation and that the regeneration after centrilobular necrosis due to CCl4 administration was retarded under this condition. In the CCl4-treated group on protein-deficient diet, the centrilobular liver cells seemed to be less responsive to CCl4.

Animals↗
PubMed2006

Cardiopulmonary bypass for a coronary artery bypass graft patient with heterozygous protein C deficiency and protein S deficiency.

Cardiopulmonary bypass (CPB) poses great risks for hypercoagulable patients and requires management techniques to ensure an optimal outcome free from thrombotic events. This case report reviews perfusion management techniques that may contribute to a safer CPB experience for a patient deficient in both protein C and protein S. A patient with heterozygous protein C deficiency is at increased risk of thrombosis, especially in the venous circulation. Since it is an essential cofactor for activated protein C, deficiency of free protein S is also linked to a hypercoagulable condition. A 52-year-old male presented to our institution with a past medical history of hypercoagulable state, multiple deep vein thromboses, pulmonary embolisms, and stroke. He was scheduled for two-vessel coronary artery bypass graft surgery to be followed by right carotid endarterectomy (RCEA) before discharge. The anesthesia and perfusion teams worked closely together to ensure that fresh frozen plasma (FFP) was given intraoperatively at appropriate times. Heparin dose response and protamine dosage was determined with hemostasis management system (HMS) analysis. The closed CPB circuit and cannulae were Carmeda bonded. Rapid autologous priming, along with the use of a hemoconcentrator, kept the hematocrit above 21 during CPB. Zero-balance ultrafiltration and leukocyte depletion were initiated during rewarming to aid in attenuation of the inflammatory response. To conserve coagulation factors, all pump blood was ultrafiltrated post-CPB and returned to the patient. Laboratory samples drawn on postoperative day (POD) one measured normal protein C activity with subnormal protein S activity. On POD six, the patient underwent RCEA and he was discharged on POD eight without complications.

Cardiopulmonary Bypass↗