A pancreatic extract-enriched diet improves the nutritional status of aged rats.

Correction of the malnourished state, particularly common and severe in elderly people, is often unsuccessful. To improve the efficiency of realimentation, we evaluated the nutritional effect of a pancreatic extract (PE)-enriched diet in malnourished aged rats. Sprague-Dawley male rats were randomly assigned to 6 groups as follows: 1 group of control rats had free access to the diet for 12 wk (C group) and 5 groups were 50% food restricted for the same period. One food-restricted group was then killed (R group) and the 4 remaining groups were refed for 1 wk using a standard diet enriched either with two different doses of a pancreatic extract (2.4 or 4.8 g/d in PE1 and PE2 groups, respectively) or with an isonitrogenous casein hydrolysate (CH1 and CH2 groups, respectively). Profound alterations induced by food restriction (FR) were moderately corrected by refeeding, except nitrogen balance, which was reestablished in rats refed all diets (P: < 0.01 vs. R). Supplementation of the food ration with a pancreatic extract clearly improved recovery. Indeed, body weight gain, both jejunal and ileal trophicity [jejunum: total height, PE2: 849 +/- 45 microm vs. CH2: 768 +/- 17 microm (P: < 0.05); protein content, PE2: 69.9 +/- 5.7 mg vs. CH2: 56.4 +/- 4.8 mg (P: < 0.01)] and nonspecific immune response in terms of H2O2 production by polymorphonuclear neutrophils and tumor necrosis factor alpha (TNF-alpha) by macrophages (PE2, 20.7 +/- 4.7 vs. CH2, 8.7 +/- 2.3, P: < 0.05) were improved in rats fed PE2. A pancreatic extract could improve the efficiency of realimentation in malnourished aged rats.

Bacterial dissemination and metabolic changes in rats induced by endotoxemia following intestinal E. coli overgrowth are reduced by ornithine alpha-ketoglutarate administration.

The efficacy of ornithine alpha-ketoglutarate (OKG) in preventing bacterial translocation and dissemination, metabolic disorders and changes in mucosal enzyme activities was assessed in a model of bacterial translocation in rats. Antibiotic decontamination was performed 4 d before intragastric inoculation with an Escherichia coli strain (10(10) bacteria/kg body). Two days later, the rats were given either a lipopolysaccharide (LPS) 0127:B8 or a saline injection and were deprived of food for 24 h. Enteral nutrition, [Osmolite, 880 kJ/(kg. d)] supplemented with either OKG (LPS + OKG) or glycine (Saline + Gly or LPS + Gly), was then given for 2 d. Urinary total nitrogen losses and 3-methylhistidine excretion were determined daily. On killing at d 3, bacterial translocation to the mesenteric lymph nodes (MLN) and dissemination to the spleen and liver were evaluated, jejunal mucosa enzyme activities were assayed and tissue free amino acids in muscles were measured. Endotoxin induced translocation from the gut lumen to the MLN in all groups, whereas dissemination occurred only in LPS-treated rats. OKG significantly reduced dissemination of the bacteria in the spleen. 3-Methylhistidine excretion was greater in the LPS + Gly group (+25%, P: < 0.05) than in either the LPS + OKG or Saline + Gly group. The group fed the OKG-enriched diet had higher muscular glutamine, ornithine and arginine concentrations than did the Gly-supplemented groups (P: < 0.05). Intestinal sucrase and aminopeptidase activities were higher in the LPS + OKG group than in the LPS + Gly group (-30%, P: < 0.05). OKG supplementation limits bacterial dissemination and metabolic changes after injury in rats and thus may be useful in the prevention of gut-derived sepsis in critically ill patients.

Trophic response of the intestinal mucosa to inflammation in rats injected with turpentine: a study using pair-fed controls.

The effects of restricted food intake and acute inflammation on the small bowel were studied, Wistar rats (250 g) were given subcutaneous injections of turpentine (TR) and compared to two control groups, at 18, 42 and 66 h. One was fed ad libitum (C), the other was pair fed (PF) with TR. The TR and PF rats showed hypoplasia of the jejunal mucosa with decreased protein and DNA contents at 42 h and 66 h. The hypoplasia resulted in a reduced villus height that was significantly different from the controls at 66 h (C: 468 +/- 17, TR[66] : 376 +/- 20, PF[66] : 258 +/- 2.9 microm, P<0.001). This decrease in villus height was significantly greater in the PF rats than in the TR rats at 66 h. The crypt height/villus height (C/V) ratio in the PF rats was greater than in the TR group at all times. However, the protein and DNA contents in the TR group were significantly higher than in the PF group at 42 h and 66 h (TR/PF[42] : 29.5 +/- 1.9 vs 20.5 +/- 2.0, P< 0.001, [66]: 25.8 +/- 2.0 vs 16.6 +/- 1.3 mg/10 cm, P,< 0.001). Disaccharidase activities (sucrase and glucoamylase) per 10 cm jejunum at 66 h were significantly lower in the PF group than in the control and TR groups (sucrase mU/10cm[66] C : 3090 +/- 144, TR 2683 +/- 479, PF 1969 +/- 144, P,< 0.001; glucoamylase mU/10 cm[66] 237 +/- 25, TR 169 +/- 40, PF 123 +/- 5, P< 0.01). The N-aminopeptidase patterns in the TR and PF groups were similar. These data suggest that dietary restriction during acute inflammation is the main factor causing hypoplasia of the jejunal mucosa. However, acute inflammation has a trophic effect on the morphological and function of the mucosa. This effect is probably due to inflammatory mediators, whose synthesis is stimulated by turpentine.

Effects of alimentary intact proteins and their oligopeptide hydrolysate on growth, nitrogen retention, and small bowel adaptation in inflammatory turpentine rat.

The effects of dietary proteins given as whole proteins (WP) or as a peptide hydrolysate (PH) on growth, nitrogen retention, and small bowel adaptation were assessed using two groups of male Wistar rats. Measurements were made 18, 42, and 66 h after acute inflammation induced by subcutaneous injections of 0.125 mL turpentine and in two control groups (n = 12). The two diets had the same caloric, nitrogen, vitamin, and mineral content. The WP diet resulted in better weight gain, nitrogen retention, and small intestinal adaptation by control rats than did the PH diet. Loss of body weight after 18 h of acute inflammation was significantly lower and nitrogen retention significantly higher in animals on the WP diet than in those on the PH diet. Small intestine morphology was maintained with the WP diet, whereas villus height was significantly lower after 66 h, and there were fewer mitoses per crypt in the rats on the PH diet. Glucoamylase activity at all times, and N-aminopeptidase activity at 18 h, were significantly higher in rats on the WP diet. The putrescine (at 42 h) and spermidine (at 18 h) concentrations in the mucosa were higher in the rats on the WP diet. These data suggest that synthetic diets should be tested for their nutritional value during acute inflammation before they are used in human nutrition.

Effects of alimentary whole proteins versus their small peptide hydrolysates on liver and skeletal muscle during the acute inflammation phase in the rat.

Acute inflammation induces changes in liver proteins with an increase in synthesis of positive acute-phase proteins such as alpha1-acid glycoprotein (alpha1-AGP) and a decrease in synthesis of negative acute-phase proteins such as albumin. This is associated with muscle wasting, mediated by increased proteolysis and impaired protein synthesis. As protein metabolism can be altered in other situations (malnutrition, growth) by the form of the dietary nitrogen, we studied the effects of the molecular form of nitrogen on liver and skeletal muscle adaptation, looking at gene expression for two acute-phase proteins (albumin and alpha1-AGP) and a number of muscle proteins (alpha1-actin, ubiquitin and C9 proteasome subunit). Two groups of 24 Wistar rats (250 g) were injected S/C with 0.125 ml turpentine/rat and were fed one of two liquid diets. These diets had caloric, nitrogen, carbohydrate and lipid content but differed in the molecular form of the nitrogen source (whole protein [WP] versus peptide hydrolysate [PH]). Liver and muscle adaptation were studied at 18, 42 or 66 h after turpentine injection. Weight, deoxyribonucleic acid and protein content of the liver were significantly higher with the WP diet than with the PH diet at 42 h and 66 h. There was more alpha1-AGP messenger ribonucleic acid (mRNA) at 18 h and less albumin mRNA at 42 h. Thus, the PH diet causes a more rapid increase in alpha1-AGP mRNA content and a smaller decrease in albumin mRNA content after turpentine injection than the WP diet. However, the changes in plasma acute-phase proteins (albumin and alpha1-AGP) were similar with the two diets. In skeletal muscle, there was no change in mRNA levels for the C9 proteasome subunit at any time point with both diets compared to the controls. However, there were greater ubiquitin mRNA levels at 18|h and less alpha-actin mRNA levels at 18 h, 42 h and 66 h following turpentine injection in the two dietary groups than in the controls. These results suggest that the molecular form of nitrogen ingested regulates hepatic gene transcription or mRNA stability of acute-phase proteins, during the early period of inflammation, but did not affect the expression of muscle proteins, which was altered by turpentine injection. Post-transcriptional control of acute-phase protein genes may contribute to the maintenance of similar plasma levels.

Antigenicity and nutritional value of selected milk proteins and their hydrolysate in growing rats.

Two liquid diets containing selected milk proteins (SMP) or its small peptide hydrolysate (SPH) were fed to growing rats for 2 wk and the effects on growth, nitrogen balance, and small intestine adaptation were determined. Residual antigenicity of the SPH diet as measured by immunodot was reduced by 98.8%. Nitrogen intakes were not different. Weight gain was significantly higher in rats fed the SMP diet. In contrast, the absolute nitrogen balance was similar, suggesting that protein storage was identical with the two diets. A better nitrogen digestion-absorption rate with the SPH diet was observed as evidenced by the significantly increased fecal excretion with the SMP diet. Small intestine adaptation showed no difference between the two diets for mucosal weight, protein content/10 cm as well as for sucrase, glucoamylase, and N-aminopeptidase total activity/10 cm or specific activity (mU/mg protein). The DNA content of the mucosa/10 cm was significantly higher suggesting a mucosal hyperplasia in the SPH diet. The data suggest that in rats the SPH diet leads to nitrogen retention and small intestine adaptation similar to that of the SMP diet, despite better body weight gain by the latter.

Effects of two protein hydrolysates on growth, nitrogen balance and small intestine adaptation in growing rats.

The effects of feeding 2 protein hydrolysates, one prepared by controlled pepsin and pancreatic protease (including elastase II) hydrolysis of milk proteins (PPPH) and the other a di- and tripeptide bacterial protease hydrolysate of bovine albumin (DTPH), on the growth, nitrogen balance and small intestine adaptation of growing rats were analyzed. Two groups of 3-week-old rats (8 rats/group) were fed the liquid diets ad libitum for 2 weeks. The diets had the same caloric, nitrogen, carbohydrate and lipid contents. The amino acid compositions fulfilled the needs of growing rats. The diet differed in the original proteins, the hydrolysis technique used and the molecular weights of the peptides. Nitrogen intakes were similar. Although there was no difference in weight gain, nitrogen balance was significantly higher in the rats fed the PPPH diet (day 4-day 6:PPPH, 60 +/- 4%, DTPH, 25 +/- 5%; day 12-day 15: PPPH, 58 +/- 3%; DTPH, 30 +/- 5%). The stool nitrogens were identical, suggesting improved nitrogen storage in the rats fed the PPPH diet. Small intestine adaptation showed that the rats on the PPPH diet had significantly more protein (mg) and DNA (microgram) per 10 cm of the jejunum (PPPH, 25.6 +/- 2, 393 +/- 20; DTPH: 15.7 +/- 2, 258 +/- 23) and sucrase-specific activity and per microgram of DNA (PPPH, 133 +/- 5.7, 9.7 +/- 0.5; DTPH, 113 v 5, 7 +/- 1). The N-aminopeptidase-specific activity was the same in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Emission spectroscopy of reactive low-voltage ion plating for metal-oxide thin films.

Excited species in the plasma present during reactive low-voltage ion plating (RLVIP) of refractory oxide films are studied by using emission spectroscopy. We believe we have found a higher ratio of atomic to molecular oxygen then reported for earlier analyses that employed a quadrupole mass spectrometer. The application of emission spectroscopy to the RLVIP process and self-actinometry are discussed with examples of stable and unstable processes.