RESUMO
The objective of this work was to better understand the effect of differences in milk protein composition, and specifically, a change in ß-casein to total casein in a milk-based matrix, on growth performance and metabolic and inflammatory responses using a piglet model. Three formulas were optimized for piglets, with similar metabolizable energy, total protein content, and other essential nutrients. Only the protein type and ratio varied between the treatments: the protein fraction of the control diet contained only whey proteins, whereas 2 other matrices contained a whey protein to casein ratio of 60:40, and differed in the amount of ß-casein (12.5 and 17.1% of total protein). Piglets fed formula containing whey proteins and caseins, regardless of the concentration of ß-casein, showed a significantly higher average daily gain, average daily feed intake, and feed efficiency compared with piglets consuming the formula with only whey protein. Consumption of the formula containing only whey protein showed higher levels of plasma glucagon-like peptide-1 and ghrelin compared with the consumption of formula containing casein and whey protein. A positive correlation was observed between postprandial time and glucagon-like peptide-1 response. The intestinal pro-inflammatory cytokine tumor necrosis factor α increased significantly in piglets fed the whey protein/casein diet compared with those fed whey protein formula. All formula-fed piglets showed a lower level of IL-6 cytokine compared with the ad libitum sow-fed piglets, regardless of composition. No significant differences in the anti-inflammatory IL-10 concentration were observed between treatment groups. Milk protein composition contributed to the regulation of piglets' metabolic and physiological responses, with whey protein/casein formula promoting growth performance and a different immune regulatory balance compared with a formula containing only whey protein. Results indicated no differences between treatments containing different levels of ß-casein.
Assuntos
Ração Animal , Caseínas/farmacologia , Citocinas/metabolismo , Proteínas do Leite/farmacologia , Animais , Caseínas/metabolismo , Dieta/veterinária , Metabolismo Energético , Feminino , Interleucina-10/metabolismo , Masculino , Leite/metabolismo , Proteínas do Leite/química , Proteínas do Leite/metabolismo , Distribuição Aleatória , Suínos , Proteínas do Soro do Leite/análise , Proteínas do Soro do Leite/metabolismo , Proteínas do Soro do Leite/farmacologiaRESUMO
We investigated the effect of protein composition and, in particular, the presence of whey proteins or ß-casein on the digestion behavior of a model infant formula using an in vivo piglet model. Three isocaloric diets optimized for piglets were prepared with the same concentrations of protein. For protein source, 1 diet contained only whey proteins and 2 contained a casein:whey protein ratio of 40:60 but differed in the amount of ß-casein. To obtain the desired protein compositions, skim milk was microfiltered at 7 or 22°C, and retentates and permeates were combined with whey protein isolate. The diets were optimized to the nutritional needs of the piglets and fed to 24 newborn piglets for 18 d. Eight piglets were also fed ad libitum with sow milk and considered only as reference (not included in the statistical analysis). The study was carried out in 2 blocks, killing the animals 60 and 120 min after the last meal. All gastric contents, regardless of diet, showed a wide range of pH. Postprandial time did not affect the pH or physical properties of the gastric digesta. The digesta from whey protein-casein formulas showed significantly higher viscosity, a higher storage modulus, and a denser microstructure than digesta obtained from piglets fed whey protein formula. The ß-casein:total casein ratio at the level used in this study did not significantly affect the physical and chemical properties of the stomach digestate. Although caseins showed extensive gastric hydrolysis, whey proteins remained largely intact at both postprandial times. The results indicate that the presence of different concentrations of milk proteins can be critical to the digestion properties of the food matrix and may affect the nutritional properties of the components.
Assuntos
Digestão , Mucosa Gástrica/metabolismo , Fórmulas Infantis/química , Proteínas do Leite/química , Leite/química , Animais , Animais Recém-Nascidos , Caseínas/farmacologia , Dieta , Feminino , Alimentos Formulados , Hidrólise , Suínos , Viscosidade , Proteínas do Soro do Leite/farmacologiaRESUMO
Objective: To investigate the effects of non-muscle myosin â ¡ (NMâ ¡) gene silenced bone marrow-derived mesenchymal stem cells (BMMSCs) on pulmonary extracellular matrix (ECM) and fibrosis in rats with acute lung injury (ALI) induced by endotoxin/lipopolysaccharide (LPS). Methods: The experimental research methods were adopted. Cells from femur and tibial bone marrow cavity of four one-week-old male Sprague-Dawley rats were identified as BMMSCs by flow cytometry, and the third passage of BMMSCs were used in the following experiments. The cells were divided into NMâ ¡ silenced group transfected with pHBLV-U6-ZsGreen-Puro plasmid containing small interference RNA sequence of NMâ ¡ gene, vector group transfected with empty plasmid, and blank control group without any treatment, and the protein expression of NMâ ¡ at 72 h after intervention was detected by Western blotting (n=3). The morphology of cells was observed by an inverted phase contrast microscope and cells labeled with chloromethylbenzoine (CM-Diâ ) in vitro were observed by an inverted fluorescence microscope. Twenty 4-week-old male Sprague-Dawley rats were divided into blank control group, ALI alone group, ALI+BMMSC group, and ALI+NMâ ¡ silenced BMMSC group according to the random number table, with 5 rats in each group. Rats in blank control group were not treated, and rats in the other 3 groups were given LPS to induce ALI. Immediately after modeling, rats in ALI alone group were injected with 1 mL normal saline via tail vein, rats in ALI+BMMSC group and ALI+NMâ ¡ silenced BMMSC group were injected with 1×107/mL BMMSCs and NMâ ¡ gene silenced BMMSCs of 1 mL labelled with CM-Diâ via tail vein, and rats in blank control group were injected with 1 mL normal saline via tail vein at the same time point, respectively. At 24 h after intervention, the lung tissue was collected to observe intrapulmonary homing of the BMMSCs by an inverted fluorescence microscope. Lung tissue was collected at 24 h, in 1 week, and in 2 weeks after intervention to observe pulmonary inflammation by hematoxylin eosin staining and to observe pulmonary fibrosis by Masson staining, and the pulmonary fibrosis in 2 weeks after intervention was scored by modified Ashcroft score (n=5). The content of α-smooth muscle actin (α-SMA), matrix metalloproteinase 2 (MMP-2), and MMP-9 was detected by immunohistochemistry in 2 weeks after intervention (n=3), the activity of superoxide dismutase (SOD), malondialdehyde, myeloperoxidase (MPO) was detected by enzyme-linked immunosorbent assay at 24 h after intervention (n=3), and the protein expressions of CD11b and epidermal growth factor like module containing mucin like hormone receptor 1 (EMR1) in 1 week after intervention were detected by immunofluorescence staining (n=3). Data were statistically analyzed with one-way analysis of variance, Bonferroni method, and Kruskal-Wallis H test. Results: At 72 h after intervention, the NMâ ¡protein expression of cells in NMâ ¡ silenced group was significantly lower than those in blank control group and vector group (with P values <0.01). BMMSCs were in long spindle shape and grew in cluster shaped like vortexes, which were labelled with CM-Diâ successfully in vitro. At 24 h after intervention, cell homing in lung of rats in ALI+NMâ ¡ silenced BMMSC group was more pronounced than that in ALI+BMMSC group, while no CM-Diâ -labelled BMMSCs were observed in lung of rats in blank control group and ALI alone group. There was no obvious inflammatory cell infiltration in lung tissue of rats in blank control group at all time points, while inflammatory cell infiltration in lung tissue of rats in ALI+BMMSC group and ALI+NMâ ¡ silenced BMMSC group was significantly less than that in ALI alone group at 24 h after intervention, and alveolar wall turned to be thinner and a small amount of congestion in local lung tissue appeared in rats of the two groups in 1 week and 2 weeks after intervention. In 1 week and 2 weeks after intervention, collagen fiber deposition in lung tissue of rats in ALI alone group, ALI+BMMSC group, and ALI+NMâ ¡ silenced BMMSC group was significantly aggravated compared with that in blank control group, while collagen fiber deposition in lung tissue of rats in ALI+BMMSC group and ALI+NMâ ¡ silenced BMMSC group was significantly improved compared with that in ALI alone group. In 2 weeks after intervention, modified Ashcroft scores for pulmonary fibrosis of rats in ALI alone group, ALI+BMMSC group, and ALI+NMâ ¡ silenced BMMSC group were 2.36±0.22, 1.62±0.16, 1.06±0.26, respectively, significantly higher than 0.30±0.21 in blank control group (P<0.01). Modified Ashcroft scores for pulmonary fibrosis of rats in ALI+BMMSC group and ALI+NMâ ¡ silenced BMMSC group were significantly lower than that in ALI alone group (P<0.01), and modified Ashcroft score for pulmonary fibrosis of rats in ALI+NMâ ¡ silenced BMMSC group was significantly lower than that in ALI+BMMSC group (P<0.01). In 2 weeks after intervention, the content of α-SMA in lung tissue of rats in ALI+BMMSC group and ALI+NMâ ¡ silenced BMMSC group were significantly decreased compared with that in ALI alone group (P<0.05 or P<0.01). The content of MMP-2 in lung tissue of rats in the 4 groups was similar (P>0.05). The content of MMP-9 in lung tissue of rats in ALI alone group was significantly increased compared with that in blank control group (P<0.01), and the content of MMP-9 in lung tissue of rats in ALI+BMMSC group and ALI+NMâ ¡ silenced BMMSC group was significantly decreased compared with that in ALI alone group (P<0.01). At 24 h after intervention, the activity of malondialdehyde, SOD, and MPO in lung tissue of rats in ALI alone group, ALI+BMMSC group, and ALI+NMâ ¡ silenced BMMSC group were significantly increased compared with that in blank control group (P<0.01), the activity of malondialdehyde in lung tissue of rats in ALI+NMâ ¡ silenced BMMSC group and the activity of SOD in lung tissue of rats in ALI+BMMSC group and ALI+NMâ ¡ silenced BMMSC group were significantly increased compared with that in ALI alone group (P<0.05 or P<0.01), and the activity of SOD in lung tissue of rats in ALI+NMâ ¡ silenced BMMSC group was significantly decreased compared with that in ALI+BMMSC group (P<0.01). The activity of MPO in lung tissue of rats in ALI+BMMSC group and ALI+NMâ ¡ silenced BMMSC group was significantly decreased compared with that in ALI alone group (P<0.01), and the activity of MPO in lung tissue of rats in ALI+NMâ ¡ silenced BMMSC group was significantly decreased compared with that in ALI+BMMSC group (P<0.01). In 1 week after intervention, the protein expression of CD11b in lung tissue of rats in ALI+NMâ ¡ silenced BMMSC group was significantly increased compared with those in the other three groups (P<0.05 or P<0.01), while the protein expressions of EMR1 in lung tissue of rats in the four groups were similar (P>0.05). Conclusions: Transplantation of NMâ ¡ gene silenced BMMSCs can significantly improve the activity of ECM components in the lung tissue in LPS-induced ALI rats, remodel its integrity, and enhance its antioxidant capacity, and alleviate lung injury and pulmonary fibrosis.
Assuntos
Lesão Pulmonar Aguda , Células-Tronco Mesenquimais , Fibrose Pulmonar , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/terapia , Animais , Medula Óssea , Colágeno/metabolismo , Endotoxinas , Matriz Extracelular , Lipopolissacarídeos/efeitos adversos , Pulmão , Masculino , Malondialdeído/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Células-Tronco Mesenquimais/metabolismo , Miosina Tipo II/metabolismo , Ratos , Ratos Sprague-Dawley , Solução Salina/metabolismo , Superóxido Dismutase/metabolismoRESUMO
BACKGROUND: Inflammatory bowel disease (IBD), a chronic inflammation of the gastrointestinal tract, is characterized by a deregulation of the mucosal immune system and resistance of activated T cells to apoptosis. Current therapeutics show limited efficacy and potential toxicity; therefore there is a need for novel approaches for the treatment of IBD. L-cysteine was examined for its ability to reduce colitis symptoms and modulate local gene expression in a DSS-induced porcine model of colitis. METHODS: Colitis was induced via intra-gastric infusion of dextran sodium sulfate (DSS), followed by the administration of L-cysteine or saline. Clinical signs, morphological measurements, histology and gut permeability were assessed for the prognosis of colitis. Local tissue production of cytokines and gene expression in the colon were analyzed by ELISA and real-time RT-PCR. RESULTS: L-cysteine supplementation attenuated DSS-induced weight loss and intestinal permeability, reduced local chemokine expression and neutrophil influx, and markedly improved colon histology. Furthermore, cysteine significantly reduced the expression of pro-inflammatory cytokines, including TNF-alpha, IL-6, IL-12p40, IL-1beta, and resulted in increased expression of the apoptosis initiator caspase-8 and decreased expression of the pro-survival genes cFLIP and Bcl-xL. CONCLUSIONS AND GENERAL SIGNIFICANCE: These results suggest that L-cysteine administration aids in restoring gut immune homeostasis by attenuating inflammatory responses and restoring susceptibility of activated immune cells to apoptosis, and that cysteine supplementation may be a novel therapeutic strategy for the treatment of IBD.
Assuntos
Colite/prevenção & controle , Cisteína/administração & dosagem , Trato Gastrointestinal/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Inflamação/prevenção & controle , Animais , Animais Recém-Nascidos , Caspase 8/genética , Colite/induzido quimicamente , Colo/efeitos dos fármacos , Colo/metabolismo , Colo/patologia , Sulfato de Dextrana , Suplementos Nutricionais , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/patologia , Expressão Gênica/efeitos dos fármacos , Subunidade p40 da Interleucina-12/genética , Subunidade p40 da Interleucina-12/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Absorção Intestinal/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Suínos , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Proteína bcl-X/genéticaRESUMO
To address the problem of manure-based environmental pollution in the pork industry, we have developed the phytase transgenic pig. The saliva of these pigs contains the enzyme phytase, which allows the pigs to digest the phosphorus in phytate, the most abundant source of phosphorus in the pig diet. Without this enzyme, phytate phosphorus passes undigested into manure to become the single most important manure pollutant of pork production. We show here that salivary phytase provides essentially complete digestion of dietary phytate phosphorus, relieves the requirement for inorganic phosphate supplements, and reduces fecal phosphorus output by up to 75%. These pigs offer a unique biological approach to the management of phosphorus nutrition and environmental pollution in the pork industry.
Assuntos
6-Fitase/química , 6-Fitase/genética , Animais Geneticamente Modificados , Fósforo/química , Saliva/enzimologia , Animais , Western Blotting , Suplementos Nutricionais , Imuno-Histoquímica , Esterco , Glândula Parótida/metabolismo , Fosfatos/farmacologia , Fósforo/metabolismo , Glândulas Salivares/metabolismo , Suínos , TransgenesRESUMO
Intestinal inflammation induced with dextran sodium sulfate (DSS) is used to study acute or chronic ulcerative colitis in animal models. Decreased gut tissue anti-inflammatory cytokine IL-10 concentration and mRNA abundance are associated with the development of chronic bowel inflammation. Twelve piglets of 3 days old were fitted with an intragastric catheter and randomly allocated into control and DSS groups by administrating either sterile saline or 1.25 g of DSS/kg body weight (BW) in saline per day, respectively, for 10 days. Growth rate and food conversion efficiency were reduced (p<0.05) in the DSS piglets compared with the control group. Quantitative histopathological grading of inflammation in the jejunum and colon collectively showed that the DSS treatment resulted in 12 fold greater (p<0.05) inflammation severity scoring in the colon than in the jejunum, indicative of chronic ulcerative colitis in the colon. Upper gut permeability endpoint was 27.4 fold higher (p<0.05) in the DSS group compared with the control group. The DSS group had higher concentrations and mRNA abundances (p<0.05) of TNF-alpha and IL-6 in the jejunal and colonic tissues compared with the control group. Colonic concentration and mRNA abundance of IL-10 were reduced (p<0.05), however, jejunal IL-10 mRNA abundance was increased (p<0.05) in the DSS group compared with the control group. In conclusion, administration of DSS at 1.25 g/kg BW for 10 days respectively induced acute inflammation in the jejunum and chronic inflammation and ulcerative colitis in the colon with substantially decreased colonic concentration and mRNA abundance of IL-10 in the young pigs, mimicking the IL-10 expression pattern in humans Associated with chronic bowel inflammation.
Assuntos
Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/metabolismo , Colo/metabolismo , Sulfato de Dextrana/toxicidade , Interleucina-10/biossíntese , Intestino Delgado/metabolismo , Animais , Animais Recém-Nascidos , Colite Ulcerativa/patologia , Colo/efeitos dos fármacos , Colo/patologia , Expressão Gênica , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Interleucina-10/genética , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/patologia , SuínosRESUMO
Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder associated with the expansion of a (CAG)n array in the MJD1 gene. We analyzed the sizes of the (CAG)n array using DNA samples from 61 members of four Chinese MJD families and 18 Chinese normal control subjects and confirmed that the (CAG)n array in 15 MJD chromosomes was expanded to 72-86 repeat units. There were no subjects with (CAG)n array sizes intermediate between those of normal and MJD affected groups. Meanwhile, we found a significant negative correlation between the age of onset of symptoms and (CAG)n array size. The largest (CAG)n array of 86 repeat units was in the youngest patient, whose age of onset was 5 years. The intergenerational increase in number of CAG repeat units was associated with the clinical phenomenon of anticipation.
Assuntos
Doença de Machado-Joseph/genética , Repetições de Trinucleotídeos , Adolescente , Adulto , Fatores Etários , Povo Asiático , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Análise de Sequência de DNARESUMO
This study was conducted to characterize enterocyte apical membrane-bound alkaline phosphatase activity in different segments of the porcine small intestine. Duodenal, jejunal, and distal ileal segments were isolated from three 26-kg pigs and enterocyte brush border membrane, enriched between 19- and 24-fold in sucrase specific activity, was prepared by Mg(2+) precipitation and differential centrifugation. With P-nitrophenyl phosphate as substrate, the optimum pH for porcine brush border membrane-bound alkaline phosphatase activity was defined to be 10.5 for all three segments. At the optimal pH, the kinetics of membrane-bound alkaline phosphatase were determined for the three intestinal segments. The affinity of this enzyme (K(m), mM) in the jejunum (0.64 +/- 0.07) was four times greater than that in the duodenum (2.75 +/- 0.59) and the distal ileum (2.71 +/- 1.14). These results indicate that different isomers of membrane-bound alkaline phosphatase might have been expressed in different segments of porcine small intestine. The maximal specific activity (V(max), micromol/mg protein . min) of this enzyme was highest in the duodenal (7.74 +/- 0.95), intermediate in the jejunal (4.31 +/- 0.18), and lowest in the distal ileal (3.53 +/- 0.84) brush border membrane. Therefore, the maximal specific activity of brush border membrane-bound alkaline phosphatase along the intestinal longitudinal axis in growing pigs decreases from the duodenum toward the distal ileum.
RESUMO
There is an overlap of carrier-mediated L-amino acid transport and apparent simple diffusion when measured in intestinal brush border membrane vesicles. Using L-threonine and L-glutamine as representative amino acids, this study was undertaken to estimate apparent simple diffusion of L-amino acids and to establish the effective dosage of HgCl2 for completely blocking carrier-mediated L-amino acid transport in porcine jejunal enterocyte brush border membrane vesicles. Jejunal mucosa was scraped from three pigs weighing 26 kg. Enterocyte brush border membrane vesicles, with an average enrichment of 24-fold in sucrase specific activity, were prepared by Mg2+-precipitation and differential centrifugation. In vitro uptake was measured by the fast filtration manual procedure. HgCl2 blocked the carrier-mediated initial transport of L-threonine and L-glutamine under Na+-gradient condition in a dose-dependent manner. At the minimal concentration of 0.165 micromol HgCl2 mg(-1) protein, carrier-mediated L-threonine and L-glutamine transport was completely inhibited. The apparent L-threonine and L-glutamine diffusion was estimated to be 8.6+/-0.7 and 12.4+/-1.0% of the total uptake at the substrate concentrations of 5 microM (L-threonine) and 50 microM (L-glutamine). Therefore, the treatment of porcine brush border membrane vesicles with a minimum of 0.165 micromol HgCl2 mg(-1) protein completely blocks carrier-mediated L-amino acid transport and enables the direct estimation of apparent L-amino acid diffusion in enterocyte brush border membrane vesicles.
Assuntos
Enterócitos/metabolismo , Glutamina/farmacocinética , Jejuno/metabolismo , Treonina/farmacocinética , Animais , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Membrana Celular/metabolismo , Difusão , Desinfetantes/farmacologia , Jejuno/citologia , Cloreto de Mercúrio/farmacologia , Microvilosidades/metabolismo , Sódio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Sacarase/metabolismo , Suínos , Vesículas Transportadoras/metabolismoRESUMO
With L-glutamine, as a representative amino acid this study was undertaken to examine the effects of substrate concentrations on initial and equilibrium amino acid uptake and intravesicular volume determined with porcine jejunal brush border membrane vesicles prepared by Mg2+-aggregation and differential centrifugation. Transport measurements (24 degrees C) were conducted by the rapid filtration manual procedure. Glutamine uptake was shown to occur into an osmotically-active space ranging between 1.09-1.58 microl/mg protein with little non-specific membrane binding. At different concentrations (in parentheses), the duration of initial glutamine uptake in both Na+ gradient and Na+-free conditions was 10 s (0.01 mM), 15 s (0.17 mM), and 20 s (1.9 and 9.4 mM), respectively. Substrate concentrations affected the duration of initial uptake, with lower substrate concentrations giving shorter duration for initial amino acid uptake. At different substrate concentrations (in parentheses), the time required to reach equilibrium glutamine uptake was 5 min (0.01 mM), 10 min (0.17 mM), and 60 min (1.9 and 9.4 mM), respectively. Thus, substrate concentrations also affected the time required to reach equilibrium uptake. The higher the substrate concentration, the longer the incubation time needed to reach equilibrium amino acid uptake. At the glutamine concentrations of 0.01, 0.17, 1.9, and 9.4 mM, the average intravesicular volume was estimated to be 1.58+/-0.21, 1.09+/-0.28, 1.24+/-0.18, and 1.36+/-0.21 microl/mg protein, respectively. Substrate concentrations had no effect (p>0.05) on the intravesicular volume of membrane vesicles. In conclusion, in the experiments on amino acid transport kinetics measured with the rapid filtration manual procedure, the incubation time used for measuring the initial uptake rate should be determined from the time course experiments conducted at the lowest substrate concentration used, whereas the intravesicular volume can be obtained from equilibrium uptake measured at any substrate concentrations.
Assuntos
Aminoácidos/metabolismo , Jejuno/metabolismo , Microvilosidades/metabolismo , Suínos/metabolismo , Animais , Transporte Biológico , Centrifugação , Glutamina/metabolismo , Cinética , Magnésio , Concentração Osmolar , SódioRESUMO
This study was conducted to determine true ileal AA digestibility coefficients and the endogenous AA outputs associated with barley samples for growing-finishing pigs using the regression analysis technique with dual digestibility markers. Six barrows, with 30.5 and 58.6 kg average initial and final BW, were fitted with a simple T-cannula at the distal ileum and fed six barley-based diets at close to ad libitum feed intake according to a 6 x 6 Latin square design. The six diets contained 97% of six barley samples varying from low to high in CP and AA contents (8.5, 9.2, 9.8, 11.5, 12.6, and 15.6% CP, respectively, on DM basis). The dietary NDF content ranged from 16.8 to 23.8% on DM basis. Chromic oxide (Cr2O3) and acid-insoluble ash (AIA) were used as digestibility markers. Each experimental period lasted 7 d. Ileal digesta were collected, at 2-h intervals, for a total of 24 h during d 6 and 7. There were linear relationships (P < 0.01) between dietary contents of apparent ileally digestible and total CP and AA as determined by using either Cr2O3 or AIA as a digestibility marker. The use of Cr2O3 vs AIA affected (P < 0.01) the determination of true ileal AA digestibility coefficients and the endogenous CP and AA outputs. However, there were no differences (P > 0.01) in the true ileal AA digestibility coefficients in barley samples between this study and the average values reported in the literature. The endogenous CP and AA outputs determined in this study were higher (P < 0.01) than reported values (35.1+/-3.0 vs 14.7+/-1.1 g CP/kg DMI). It is concluded that dual digestibility markers should be used to measure true ileal AA digestibility coefficients and endogenous AA outputs when dietary fiber content is high and the ileal digesta is collected through a simple T-cannula in the pig. True rather than apparent ileal AA digestibility coefficients determined in barley samples should be used in diet formulation for swine. The gastrointestinal endogenous AA secretion, recycling, and output losses are important in whole-body AA utilization and homeostasis, especially when fiber-enriched diets are fed to growing-finishing pigs.
Assuntos
Aminoácidos/metabolismo , Hordeum/metabolismo , Íleo/metabolismo , Suínos/metabolismo , Aminoácidos/administração & dosagem , Ração Animal , Animais , Compostos de Cromo , Fibras na Dieta/administração & dosagem , Fibras na Dieta/metabolismo , Proteínas Alimentares/administração & dosagem , Proteínas Alimentares/metabolismo , Digestão , Masculino , Modelos Biológicos , Análise de RegressãoRESUMO
Three methods were evaluated for the determination of apparent ileal digestibility values of amino acids in feedstuffs with a low protein (barley, 10.2% CP) and a high protein content (canola meal, 38.2% CP). Five barrows, average initial BW 40 kg, were fitted with a simple T-cannula at the distal ileum and fed five diets according to a 5 x 5 Latin square design. Diet 1 contained 42.7% canola meal providing the sole source of dietary amino acids. Diets 2, 3, and 4 contained three graded levels of barley (22.5, 45.0, and 67.5%, respectively) and three graded levels of canola meal (36.6, 30.5, and 24.4%, respectively). Diet 5 contained 90.0% barley, which provided the sole source of dietary amino acids. With the exception of diet 5, the diets were formulated to contain 16% CP. Chromic oxide (.4%) was included as the digestibility marker. The pigs were fed twice daily, equal amounts, at 0800 and 2000. The dietary allowance was 1,800 g/d. Each experimental period comprised 8 d. Ileal digesta were collected for a total of 24 h during d 7 and 8 at 2-h intervals. Apparent ileal digestibility values of amino acids in barley were determined with the direct method from diet 5, with the difference method from diets 2, 3, and 4, and with the regression method from diets 1, 2, 3, and 4. Digestibility values of amino acids in canola meal were determined with the direct method from diet 1, with the difference method from diets 2, 3, and 4, and with the regression method from diets 1, 2, 3, and 4. There were no differences (P < .05) in the digestibility values in barley between the difference method when barley was included at 67.5% in the diet and the regression method. However, the digestibility values were lower (P < .05 or < .10) when these were determined with the direct method. There were no differences (P > .05) in the digestibility values of canola meal when these were determined with the direct method, the difference method, when canola meal was included at 36.6% in the diet, and the regression method. In conclusion, amino acid digestibility values in feedstuffs with a low protein content should be determined with the difference or regression methods rather than with the direct method. Amino acid digestibility values in feedstuffs with a high protein content can be determined with either method.
Assuntos
Aminoácidos/metabolismo , Brassica/metabolismo , Digestão/fisiologia , Hordeum/metabolismo , Íleo/metabolismo , Suínos/metabolismo , Aminoácidos/análise , Animais , Brassica/química , Compostos de Cromo/metabolismo , Proteínas Alimentares/metabolismo , Hordeum/química , Modelos Lineares , Masculino , Suínos/fisiologia , Fatores de TempoRESUMO
Our objective was to examine the distribution of enterocyte digestive enzyme activity along the crypt-villus and longitudinal axes of the small intestine in formula-fed neonatal pigs between the ages of 14 and 18 d. The distended intestinal sac method was used to isolate 12 sequential fractions (F1 through F12) of epithelial cells. Enterocyte migration rate was measured in the proximal and distal intestine using in vivo bromodeoxyuridine labeling. Specific activities of representative villus cell marker enzymes of alkaline phosphatase, aminopeptidase N, sucrase, and lactase increased 6- to 17-fold from F12 (crypt cells) to F1 (villus cells), whereas the crypt cell marker [3H]thymidine incorporation increased 8- to 18-fold from F1 (villus cells) to F12 (crypt cells). Enterocyte migration rate was similar (3.2 vs 3.0 microm/h), whereas the villus height (547.4 vs 908.5 microm) and enterocyte life span (4.7 vs 10.2 d) were markedly lower (P < 0.05) in the proximal than in the distal segments, respectively. In general, the specific activities of all enzymes were lowest in the crypt fractions (F9 through F12) but increased markedly (ranging from 8- to 17-fold) from F12 to F1. The activity of aminopeptidase N was higher and that of sucrase was lower in the distal than in the proximal segment. The activities of the remaining enzymes were similar in the proximal and the distal segments. Our results suggest that the enterocyte life span in the distal small intestine is approximately twice as long as in the proximal small intestine. However, despite the difference in life span, the patterns of enzyme activities along the crypt-villus axis were generally similar in the proximal and the distal regions.
Assuntos
Proteínas de Transporte de Cátions , Mucosa Intestinal/enzimologia , Intestino Delgado/enzimologia , Suínos/metabolismo , Adenosina Trifosfatases/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Animais Recém-Nascidos , Antígenos CD13/metabolismo , Movimento Celular/fisiologia , Células Epiteliais/citologia , Células Epiteliais/enzimologia , Histocitoquímica/veterinária , Processamento de Imagem Assistida por Computador , Absorção Intestinal , Mucosa Intestinal/citologia , Mucosa Intestinal/crescimento & desenvolvimento , Intestino Delgado/citologia , Intestino Delgado/crescimento & desenvolvimento , Lactase , Microvilosidades/enzimologia , Contagem de Cintilação/veterinária , ATPase Trocadora de Sódio-Potássio/metabolismo , Sacarase/metabolismo , Suínos/crescimento & desenvolvimento , beta-Galactosidase/metabolismoRESUMO
An experiment was conducted to estimate by simple linear regression the levels of endogenous amino acids in digesta collected from the distal ileum in pigs. Six barrows, average initial BW 35 kg, were fitted with a simple T-cannula at the distal ileum and fed six diets according to a 6 x 6 Latin square design. Six cornstarch-based diets containing six levels of CP from soybean meal (4, 8, 12, 16, 20, and 24% CP, respectively) were formulated. Chromic oxide (.4%) was included as the digestibility marker. Each experimental period consisted of 8 d. Ileal digesta were collected, at 2-h intervals, for a total of 24 h during d 7 and 8. There were linear relationships (P < .001) between dietary contents of apparent ileal digestible and total amino acids, irrespective of the ranges in graded dietary levels of amino acids. Determined with the regression technique, the endogenous levels of the indispensable amino acids (grams/kilogram of DMI) were as follows: arginine, .64; histidine, .23; isoleucine, .46; leucine, .69; lysine, .47; methionine, .13; phenylalanine, .31; threonine, .69; and valine, .54. Differences in the ranges of graded dietary levels of amino acids resulted in large differences in the estimated amounts of endogenous amino acids in ileal digesta. Furthermore, it seems that the levels of endogenous amino acids, as grams/kilogram of DMI, were constant at different dietary levels of amino acids, whereas the contributions of endogenous amino acids, as percentages of their dietary contents, decreased curvilinearly with increasing dietary contents. Therefore, apparent ileal digestibilities of amino acids were quadratically related to their dietary contents until plateau digestibilities were reached, whereas the true ileal digestibilities of amino acids were independent of their respective dietary contents. Furthermore, true ileal amino acid digestibilities should be determined from their corresponding plateau apparent ileal digestibilities. In conclusion, the levels of endogenous amino acids in ileal digesta can be determined reliably from the linear relationships between dietary contents of apparent ileal digestible and total amino acids. An important methodological consideration in the determination of endogenous amino acids by regression analysis is to design an appropriate range of graded dietary levels of amino acids.
Assuntos
Aminoácidos/análise , Digestão/fisiologia , Conteúdo Gastrointestinal/química , Íleo/química , Suínos/metabolismo , Aminoácidos/metabolismo , Animais , Arginina/análise , Arginina/metabolismo , Histidina/análise , Histidina/metabolismo , Íleo/metabolismo , Modelos Lineares , Lisina/análise , Lisina/metabolismo , Masculino , Metionina/análise , Metionina/metabolismo , Fenilalanina/análise , Fenilalanina/metabolismo , Proteínas/análise , Proteínas/metabolismo , Glycine max/química , Glycine max/metabolismo , Suínos/fisiologia , Treonina/análise , Treonina/metabolismo , Valina/análise , Valina/metabolismoRESUMO
Studies were carried out to investigate the effect of dietary amino acid level on apparent ileal amino acid digestibility. Six barrows, average initial BW 35 kg, were fitted with a simple T-cannula at the distal ileum and fed six diets according to a 6 x 6 Latin square design. Six cornstarch-based diets containing six levels of CP from SBM (4, 8, 12, 16, 20, and 24% CP, respectively) were formulated. Chronic oxide was included as a digestibility marker. Each experimental period consisted of 8 d. After a 6-d adaptation period, ileal digesta were collected for 24 h during d 7 and 9 at 2-h intervals. The pigs were fed twice daily, equal amounts, at 0800 and 2000. The dietary allowance was 1,600 g/d during the first period and increased by 100 g each following period. There was a quadratic increase (P < .05) in apparent ileal amino acid digestibility as the dietary CP content was increased from 4 to 24%. Initially, the apparent ileal amino acid digestibilities increased sharply then gradually reached their plateaus, after which there were no further increases and the digestibility values became independent of the dietary amino acid levels. The lower end points of 95% confidence intervals of the plateau ileal digestibility values were defined to be the initial plateau digestibilities. The dietary CP and amino acid contents, corresponding to the initial plateau digestibility values, represent the dietary threshold levels.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Aminoácidos/metabolismo , Proteínas Alimentares/análise , Digestão/fisiologia , Íleo/fisiologia , Suínos/fisiologia , Aminoácidos/administração & dosagem , Aminoácidos/análise , Ração Animal/análise , Animais , Íleo/química , Masculino , Modelos BiológicosRESUMO
The excretion of major odor-causing and acidifying compounds in response to dietary supplementation of chicory inulin extract was investigated with six Yorkshire barrows, with an average initial BW of 30 kg, according to a balanced two-period cross-over design. The animals were fed a control diet containing no inulin extract and a treatment diet with 5% inulin extract (as-fed basis) at the expense of cornstarch. Each diet was formulated (as-fed basis) to contain 16% CP from corn (51%) and soybean meal (29%). Each experimental period lasted 14 d, with 10 d for dietary adaptation and 4 d for collection of fecal and urine samples. The fecal samples were analyzed for four major classes of odor-causing and acidifying compounds: 1) VFA; 2) N-containing compounds, including total N and ammonia; 3) volatile sulfides measured as hydrogen sulfide units; and 4) phenols and indoles, including p-cresol, indole, and skatole. Supplementation of chicory inulin at 5% had no effects on the fecal excretion of VFA (P = 0.29), ammonia (P = 0.96), total volatile sulfides (P = 0.56), p-cresol (P = 0.56), and indole (P = 0.75). Fecal excretion of total N (inulin = 6.13 vs. control = 5.10 g/kg DMI) was increased (P < 0.05), whereas urinary total N excretion (inulin = 15.1 vs. control = 16.4 g/[pig x d]) was not affected (P = 0.17) by the inulin supplementation compared with the control group. Furthermore, fecal excretion of skatole (inulin = 9.07 vs. control = 18.93 mg/kg DMI) was decreased (P < 0.05) by the inulin supplementation compared with the control group. In conclusion, dietary supplementation of 5% chicory inulin extract is effective in decreasing the fecal excretion of skatole in growing pigs fed corn and soybean meal diets.
Assuntos
Cichorium intybus , Inulina/metabolismo , Odorantes/prevenção & controle , Suínos/metabolismo , Amônia/metabolismo , Amônia/urina , Ração Animal , Animais , Estudos Cross-Over , Suplementos Nutricionais , Ácidos Graxos Voláteis/biossíntese , Fezes/química , Inulina/administração & dosagem , Masculino , Nitrogênio/metabolismo , Nitrogênio/urina , Fenóis/metabolismo , Fenóis/urina , Distribuição Aleatória , Escatol/metabolismo , Suínos/crescimento & desenvolvimentoRESUMO
The objectives of this study were to determine true P digestibility, the gastrointestinal endogenous P outputs associated with soybean meal (SBM), and the role of the large intestine in P digestion in growing pigs. Four Yorkshire barrows, with average initial and final BW of 40 and 58 kg, were fitted with a simple T-cannula at the distal ileum and fed four diets according to a 4 x 4 Latin square design. The diets were cornstarch-based and contained four levels of P (0.098, 0.196, 0.293, and 0.391% on a DM basis) from solvent-extracted conventional SBM. Chromic oxide (3.5 g/kg of diet, as-fed basis) was included as a digestibility marker. Each experimental period consisted of 8 d with a 4-d adaptation period and a 4-d collection of representative ileal digesta (2 d) and fecal (2 d) samples. True ileal and fecal P digestibility values and the ileal and fecal endogenous P outputs associated with SBM were determined by the regression analysis technique. There were no differences (P > 0.05) in true P digestibility values (ileal, 59.0 +/- 8.3 vs. fecal, 51.3 +/- 7.9%, n = 16) and endogenous P outputs (ileal, 0.59 +/- 0.18 vs. fecal, 0.45 +/- 0.21 g/kg of DMI, n = 16) between the ileal and the fecal levels. The endogenous fecal P loss accounted for 8.1 and 17.6% of the NRC (1998) recommended total and available P requirements in growing pigs, respectively. In conclusion, approximately 51% of the total P in conventional SBM is digested in growing pigs. The large intestine does not play an important role in the digestion of P associated with SBM in the growing pig. The fecal loss of the gastrointestinal endogenous P is an important route of P excretion in the growing pig.
Assuntos
Digestão , Glycine max , Íleo/metabolismo , Fósforo/metabolismo , Suínos/metabolismo , Animais , Compostos de Cromo/metabolismo , Relação Dose-Resposta a Droga , Fezes/química , Absorção Intestinal , Masculino , Necessidades Nutricionais , Valor Nutritivo , Distribuição Aleatória , Análise de Regressão , Suínos/crescimento & desenvolvimentoRESUMO
Radioactivity distribution of 125I-labelled F(ab')2 fragments in 14 organs and tissues of normal mice for 11 time-phases from 0.5 hour to 7 days after injection was observed. The radioactivity-time curves of these organs and tissues were divided into three types according to their characteristics: excreting type (blood and liver), absorbing type (thyroid), absorbing-excreting type (the other organs and tissues). The organs fully perfused with blood had shorter peak-time and higher peak-value, such as heart, lung, kidney and liver. All of the peak-times were equal to or less than 2 days after injection, therefore the image taking should be kept away from this period. The excreting rate constants of slow metabolic component were similar for various organs and tissues except thyroid and brain. The brain had a low peak in the curve and small excreting rate constant. It was demonstrated that F(ab')2 fragments were able to penetrate the blood-brain barrier but absorption and excretion were slower compared with the other organs and tissues. The radioiodine was obviously concentrated in the subcutaneous tissue, which may have been the main cause of the subcutaneous tissue tumor induced by radioiodine. The radioactivity-time curve in which the peak value and inflect point existed simultaneously shows that radioactivity metabolism after injection of 125I-F(ab')2 follows three compartment models. The biological meanings corresponding to three sections of the blood radioactivity-time curve are pure distribution, distribution-recycle and catabolic-excretory phases, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Anticorpos Monoclonais/análise , Carcinoma de Células Escamosas/metabolismo , Fragmentos Fab das Imunoglobulinas/análise , Neoplasias Pulmonares/metabolismo , Animais , Barreira Hematoencefálica , Carcinoma de Células Escamosas/imunologia , Feminino , Humanos , Radioisótopos do Iodo , Cinética , Neoplasias Pulmonares/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Distribuição TecidualRESUMO
Two IgG1 type monoclonal antibodies ALT-01 and ALT-04 were prepared by two different immunization schedules. ALT-01 was generated by fusing murine myeloma NS-1 cells with splenocytes from a BALB/c mouse immunized by human lung squamous carcinoma cells, which were coated by antisera to mixed human lymphocytes. For preparation of ALT-04, human lung squamous carcinoma xenograft-bearing nude mice were injected I. P. with the spleen cells of normal BALB/c mice in order to acquire immunofunction. The spleen cells from these tumor-bearing nude mice were fused with NS-1 cells. Then, these hybridomas were screened and cloned for 3 times. Two antibodies were shown to recognize the surface antigen on human lung carcinoma cells and several kinds of tumor cell lines but not those on normal cell lines. ALT-01 reacted to neither human lung carcinoma tissue nor its xenograft. ALT-04 reacted to human lung carcinoma tissue, of which, reaction to adenocarcinoma was the strongest but not to various normal tissues. Immunoprecipitation followed by SDS-polyacrylamide gel electrophoresis and autoradiography was used to detect the associated antigen in 35S-labeled human lung carcinoma cells. Antigens, reacting to ALT-01, show one band of Mr 38,000 but those to ALT-04 reveal two bands of Mr 48,000 and 36,000.
Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antineoplásicos/imunologia , Antígenos de Neoplasias/análise , Carcinoma de Células Escamosas/imunologia , Neoplasias Pulmonares/imunologia , Animais , Linhagem Celular , Humanos , Camundongos , Camundongos Nus , Transplante de NeoplasiasRESUMO
Three nude mouse models bearing the human lung cancer were established from two fresh surgical specimens and one cell line. Tumor histological structure and cell morphology were similar before and after transplantation. The monoclonal antibody ALT-04 (McAb ALT-04) against human lung cancer was labeled by 125I, 131I and 201Tl. Radioimmunodetection study showed that all the three kinds of xenografts in nude mice were specifically located by McAb ALT-04. Imaging examination confirmed the ability of isotope labeling McAb ALT-04 to detect the presence of transplanted human lung cancer tissues without the aid of background subtraction manipulations. It is suggested that McAb ALT-04 have the possibility of locating in the tumor diagnosis and guiding in the treatment.