Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PEPTONES”

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 739 records · Page 41Linked to original sources
PubMed1999

Decreased responsiveness to dietary fat in Otsuka Long-Evans Tokushima fatty rats lacking CCK-A receptors.

Adult Otsuka Long-Evans Tokushima fatty (OLETF) rats lack functional cholecystokinin A (CCK-A) receptors, are diabetic, hyperphagic, and obese, and have patterns of ingestion consistent with a satiety deficit secondary to CCK insensitivity. Because dietary fat potently stimulates CCK release, we examined how dietary fat modulates feeding in adult male OLETF rats and their lean [Long-Evans Tokushima (LETO)] controls. High-fat feeding produced sustained overconsumption of high-fat diet (30% corn oil in powdered chow) over a 3-wk period in OLETF but not LETO rats. We then assessed the ability of gastric gavage (5 ml, 1-2 kcal/ml x 15 s) or duodenal preloads (1 kcal/ml, 0.44 ml/min x 10 min) of liquid carbohydrate (glucose), protein (peptone), or fat (Intralipid) to suppress subsequent 30-min 12.5% glucose intake in both strains. In OLETF rats, gastric and duodenal fat preloads were significantly less effective in suppressing subsequent intake than were equicaloric peptone or glucose. These results demonstrate that OLETF rats fail to compensate for fat calories and suggest that their hyperphagia and obesity may stem from a reduced ability to process nutrient-elicited gastrointestinal satiety signals.

Animals↗
PubMed1989

Cholinergic regulation of PP release is mediated through muscarinic M1-receptors.

The effects of the selective muscarinic M1-receptor antagonist pirenzepine and the nonselective muscarinic antagonist atropine on bombesin- and peptone-stimulated release of pancreatic polypeptide (PP) were studied in healthy subjects. To exclude any effect of changes in intraduodenal pH continuous intragastric titration was performed during all tests. Both pirenzepine (i.v. bolus 0.6 mg/kg) and atropine (i.v. bolus 15 micrograms/kg, followed by an infusion of 5 micrograms/kg.h) significantly reduced peptone-induced integrated mean rise of plasma PP from 28 +/- 5 to 8 +/- 4 and -2 +/- 5 pmol/l, respectively (n = 4). Both drugs also reduced bombesin-induced rise of plasma PP in all 4 subjects, from 27 +/- 12 to 6 +/- 4 and 7 +/- 1 pmol/l (0.05 less than p less than 0.1). It is concluded that cholinergic regulation of PP release is mediated mainly through muscarinic M1-receptors.

Adult↗
PubMed1990

Cholecystokinin in the inhibition of gastric secretion and gastric emptying in humans.

Cholecystokinin (CCK) is known to inhibit gastric acid secretion and gastric emptying but its physiological role in the inhibition of gastric functions is not settled. In this study performed on 16 young male subjects, gastric acid secretion and emptying rate were determined after intragastric administration of 8% peptone meal alone or in combination with intravenous infusion of graded doses of CCK-8 (5-80 pmol/kg.h) or with addition of vegetable oil to meal without or with pretreatment with loxiglumide, a specific CCK antagonist. CCK-8 infusion at lower dose (5 pmol/kg.h) was ineffective but at higher doses (20-80 pmol/kg.h) it resulted in a significant reduction in acid output by 39 and 43% and a decrease in gastric emptying from 54% to 40 and 22%, respectively. Pretreatment with loxiglumide abolished almost completely the inhibition of both gastric acid and gastric emptying by CCK-8. Fat added to peptone meal reduced gastric acid secretion by 42-65% and decreased gastric emptying to 24-32%. The pretreatment with loxiglumide tended to reduce fat-induced inhibition of gastric acid secretion and gastric emptying but the difference in the inhibition of gastric functions between the tests without and with loxiglumide was not significant. This study provides evidence that exogenous CCK administered at pharmacological doses is a potent inhibitor of gastric acid secretion and gastric emptying and probably acts via specific CCK receptors. In contrast, fat induces inhibition of gastric acid secretion and gastric emptying that cannot be fully attributed to hormonally acting CCK.

Adult↗
PubMed1987

Increased sensitivity of gastric acid secretion to gastrin in cirrhotic patients with portacaval shunt.

We studied acid secretory responses to exogenous pentagastrin and to exogenous and endogenous gastrin in 12 stable cirrhotic subjects with portacaval shunt, 12 unshunted cirrhotics, and 12 normal subjects. Basal and stimulated serum gastrin concentrations as well as basal and maximum acid outputs were similar in the three groups. At low doses of either exogenous pentagastrin or gastrin-17 (G17), cirrhotics with portacaval shunt secreted significantly greater amounts of gastric acid than unshunted subjects. After low doses of intragastric peptone, cirrhotics with portacaval shunt secreted significantly more acid than unshunted cirrhotics and normal subjects. At each measured serum gastrin concentration after either exogenous G17 or intragastric peptone meals, cirrhotics with portacaval shunt secreted more acid than the unshunted control groups and their dose-response curve was significantly shifted to the left. Thus, in cirrhotic patients with portacaval shunt, gastric acid secretion is abnormally sensitive to both exogenously administered or endogenously released gastrin.

Aged↗
PubMed1986

Unexpected presence of estrogens in culture medium supplements: subsequent metabolism by the yeast Sacchromyces cerevisiae.

We have previously shown the presence of 17 beta-estradiol in extracts of commercially prepared Saccharomyces cerevisiae ss well as the production of estradiol by yeast grown in the laboratory. In our current study, yeast grown in a chemically defined medium synthesized estradiol in only small amounts, (less than 500 pg/liter). We have analyzed a variety of media commonly used for growing yeast and found that substantial estradiol production (greater than 5 ng/liter) was obtained when yeast were grown in medium supplemented with Bacto-peptone. The peptone was shown to contain significant amounts of estrone, and the results of the experiments establish a precursor-product relationship where estrone from the medium is metabolized to estradiol by S. cerevisiae. Studies with added [3H]estrone demonstrated rapid conversion into [3H]estradiol and a 3H-labeled nonpolar estrogen derivative. The commercially obtained yeast used previously had been grown in a molasses medium. We demonstrate here that the molasses medium contains substantial amounts of estrone and estradiol. We conclude that the conversion of estrone in a culture medium to estradiol in laboratory grown yeast and estrone and estradiol present in the commercially grown yeast medium account for the majority of estradiol found in yeast.

Chromatography, High Pressure Liquid↗
PubMed2000

Lipase production by Penicillium restrictum using solid waste of industrial babassu oil production as substrate.

Lipase, protease, and amylase production by Penicillium restrictum in solid-state fermentation was investigated. The basal medium was an industrial waste of babassu oil (Orbignya oleifera) production. It was enriched with peptone, olive oil, and Tween-80. The supplementation positively influenced both enzyme production and fungal growth. Media enriched with Tween-80 provided the highest protease activity (8.6 U/g), whereas those enriched with peptone and olive oil led to the highest lipase (27.8 U/g) and amylase (31.8 U/g) activities, respectively.

Amylases↗
PubMed1983

The effect of vasoactive intestinal polypeptide on meal-stimulated gastric acid secretion in man.

The effect of vasoactive intestinal polypeptide (VIP) on meal-stimulated gastric acid secretion was studied in six healthy volunteers. Acid secretion was stimulated by instillation of a 10% solution of peptone, which was adjusted to pH 5.5, circulated through the stomach via a double-lumen gastric tube by a peristaltic pump. The acid secretion was estimated by continuous titration by a pH-stat. The subjects were studied twice on separate days, receiving an intravenous infusion of either VIP (1 microgram/kg/h) or saline. No effect on acid secretion was found. Mean serum gastrin concentration rose from 42 pmol/l to 150 pmol/l during meal stimulation and was unaffected by infusion of VIP. Plasma VIP concentration during infusion of saline was 6.8 pmol/l and during VIP infusion, 82.8 pmol/l. Plasma VIP concentration was unaffected by the peptone meal.

Adult↗
PubMed1987

Pharmacological effects of secretin and somatostatin on gastric and renal function in man.

In this randomized, double-blind, placebo-controlled study therapeutic doses of synthetic secretin (0.5 CU/kg/h) and somatostatin (3.5 micrograms/kg/h) given an intravenous infusion suppressed significantly peptone-stimulated gastric acid output per 3 h in nine male healthy subjects from 59.2 +/- 7.4 mmol H+ (placebo) to 16.9 +/- 3.1 and 6.6 +/- 1.5 mmol H+, respectively. Peptone-stimulated gastrin release was reduced to basal concentrations by both hormones. In five subjects secretin raised serum lipase to pathological concentrations. Somatostatin diminished significantly mean blood glucose concentrations. Both had opposite renal effects; secretin showed diuretic and somatostatin antidiuretic properties. Secretin and somatostatin were well tolerated. It is concluded from these data that therapeutic doses of secretin and somatostatin are comparably effective on exocrine and endocrine gastric functions, but have opposite effects on renal functions in man.

Adult↗
PubMed1975

[Effect of the diluent on the aerobic bacterial count in raw minced meat and similar meats (author's transl)].

A report on the changes in the aerobic bacterial count in commercial minced meat, which appear when samples, decimally diluted with 0.85 per cent sodium chloride or with 0.85 per cent sodium chloride plus peptone (peptone physiological saline solution, p.ph.s.s.) are stored at room temperature for some time. When the higher dilutions (10(5) to 10(7) inclusive) were stored for periods of thirty minutes and more, significantly higher counts were recorded on using p.ph.s.s. and significantly lower counts were observed on using sodium chloride. Significantly higher counts were produced, however, when the two diluents were used following storage of the lowest dilution (10(1)) for a similar period. The dilutions have to be mixed again after each period of storage. The presence of "sublethally injured" bacteria in commercial minced meat is discussed. These bacteria may recover when a diluent having a sufficiently protective effect is used. Substances from the natural substrate are probably still active at the lowest dilution. A number of the injured bacteria which fail to multiply when the pour-plate method is used, will probably be able to produce colonies when the streak-plate method is adopted as more oxygen will be present in this case. Even when a rapid procedure is used in examining the samples (mixed agar method), the average number of colonies produced on using sodium chloride will be significantly smaller than that produced when p.ph.s.s. is used.

Aerobiosis↗
PubMed1975

Comparison of secretin and vasoactive intestinal peptide on pancreatic secretion in dogs.

Vasoactive inhibitory peptide (VIP) and secretin were compared in regard to the stimulation of pancreatic bicarbonate secretion and the augmentation of pancreatic response to caerulein or a peptone meal in chronic gastric and pancreatic fistula dogs. Dose-response analysis showed that maximal bicarbonate response to VIP was about 17% of that to secretin. Both caerulein and endogenous cholecystokinin, released by a peptone meal, clearly potentiated pancreatic bicarbonate response to VIP in a manner similar to secretin. The interactions of these two peptides showed that VIP is a potent inhibitor of secretin-induced pancreatic secretion. From the dose-response curves to secretin alone and secretin plus VIP, Michaelis-Menten analysis showed typical competitive inhibition, which indicates that VIP and secretin share a common receptor site.

Amylases↗
PubMedDate not supplied

[Amylases of the fungus Aspergillus flavipes associated with Fucus evanescens].

A promising producer of extracellular amylases, Aspergillus flavipes, was selected from 245 strains of marine fungi. Depending on the conditions of growth, this strain produced diverse amylolytic complexes. When grown on medium containing peptone and yeast extract (pH 7.0), A. flavipes synthesized three forms of amylase, differing in pH optimum (5.5, 6.0, and 7.5). A single form of the enzyme was synthesized either in the absence of peptone from the medium or at the initial pH value of the medium, equal to 8.6. The activity of the isolated amylase forms decreased in the presence of proteolytic enzymes. New, highly stable forms of amylase (with pH optima of 5.5 and 7.5 and maximum activity at 60-80 degrees C) were synthesized in the presence of diisopropyl fluorophosphate, an inhibitor of proteases.

Amylases↗
PubMedDate not supplied

Response surface optimization of the critical medium components for the production of alkaline protease by a newly isolated Bacillus sp.

PURPOSE: Optimization of the fermentation medium for maximum alkaline protease production was carried out using a new strain, Bacillus Sp. PE-11. METHODS: The carbon source (glucose), the nitrogen source (peptone) and salt solution were selected to optimize. A 2(3 )full factorial composite experimental design and response surface methodology were used in the design of experiments and in the analysis of results. This procedure limited the number of actual experiments performed while allowing for possible interactions between the three components. RESULTS AND DISCUSSION: The optimum values for the tested variables for the maximum alkaline protease production were; glucose 7.798 (g/L), peptone 9.548 (g/L) and salt solution 8.757%. The maximum alkaline protease production was 4,98,123 PU/L. This method was efficient; only 20 experiments were necessary to assess these conditions, and model adequacy was very satisfactory, as the coefficient of determination was 0.941. CONCLUSIONS: In the work, we have demonstrated the use of a central composite factorial design by determining the conditions leading to the high yield of enzyme production. Thus, smaller and less time consuming experimental designs could generally suffice for the optimization of many fermentation processes.

Analysis of Variance↗
PubMed1976

Effect of growth hormone release-inhibiting hormone on gastric secretion, mucosal blood flow, and serum gastrin.

In dogs with gastric fistulae and Heidenhain pouches (HP) growth hormone release-inhibiting hormone (GH-RIH) infused intravenously in a dose of 2.5 mug per kg per hr inhibited almost completely acid and pepsin responses to pentagastrin, Urecholine, and a peptone. Histamine-induced acid secretion was more resistant to the inhibition by GH-RIH, and only acid secretion evoked by the lower doses of histamine was suppressed by this peptide. The inhibition of pentagastrin-induced gastric secretion was associated with a marked reduction in mucosal blood flow. The ratio of aminopyrine concentration in the gastric juice and blood plasma was not significantly changed by GH-RIH, indicating that the reduction in mucosal blood flow was secondary to an inhibition of gastric secretion. Gastric acid and serum gastrin responses to a peptone meal adjusted to pH 5.0 and kept in the main stomach at this same pH by intragastric titration were significantly decreased by GH-RIH, indicating that the observed acid inhibition could be attributed at least in part to the suppression of gastrin release. GH-RIH inhibited acid secretion from HP stimulated by liver extract in HP. The finding that GH-RIH inhibits gastric secretion induced by exogenous stimulants as well as by the direct chemical stimulation of the HP mucosa without changing serum gastrin level suggests that the major action of GH-RIH is a direct suppression of the oxyntic glands.

Animals↗
PubMedDate not supplied

[Comparative characterization of Vibrio cholerae O1, isolated from surface water reservoirs in Grozny in 1995 and 2000].

The results of complete identification revealed the phenotypical similarity of V. cholerae strains isolated from surface water reservoirs im Grozny in 1995 and 2000. The strains under study proved to be atoxigenic, hemolysis-positive and phage resistant. The modified method of subculturing from peptone water 1 to peptone water 2 was more labor-consuming, but it was used in the bacteriological laboratory of the specialized antiepidemic brigade with the aim of more profound study of open reservoirs for the presence of V. cholerae with the positive result.

Bacterial Proteins↗
PubMedDate not supplied

[Role of hydrogenases 1 and 2 in the hydrogen dependent nitrate respiration by Escherichia coli].

The study of Escherichia coli mutants synthesizing either hydrogenase 1 (HDK203) or hydrogenase 2 (HDK103) showed that the nitrate-dependent uptake of hydrogen by E. coli cells can be accomplished through the action of either of these hydrogenases. The capability of the cells for hydrogen-dependent nitrate respiration was found to be dependent on the growth conditions. E. coli cells grown anaerobically without nitrate in the presence of glucose were potentially capable of nitrate-dependent hydrogen consumption. The cells grown anaerobically in the presence of nitrate exhibited a much lower capability for nitrate-dependent hydrogen consumption. The inhibitory effect of nitrate on this capability of bacterial cells was either weak (the mutant HDK203) or almost absent (the mutant HDK103) when the cells were grown in the presence of peptone and hydrogen. Hydrogen stimulated the growth of the wild-type strain and the mutant HDK103 (but not the mutant HDK203) cultivated in the medium with nitrate and peptone. These data suggest that hydrogenase 2 is much more active in catalyzing the nitrate-dependent hydrogen consumption than is hydrogenase 1.

Anaerobiosis↗
PubMed1992

Development of Arthrinium species on several nitrogen sources.

The aim of this study was to determine the growth aspects of Arthrinium strains in the presence of several nitrogen sources. The addition of tryptone, peptone or soybean peptone to the culture medium stimulated larger colony diameters in most of the isolates.

Culture Media↗
PubMed2005

Improvement of xylanase production in solid state fermentation by alkali-tolerant Aspergillus fumigatus MKU1 using a fractional factorial design.

Optimization of media for the maximum production of xylanase by Aspergillus fumigatus MKUI was carried out using De Meo's fractional factorial design with seven components such as NaNO3, K2HPO4, MgSO4, FeSO4. KCl, peptone and yeast extract. A. fumigatus produced a maximum of 700 U/gds of enzyme after 48 hr of incubation (before optimization). After two steps of optimization, the medium designed favoured a 2.8 fold (1950 U/gds) increase in xylanase production by A. fumigatus. Optimized medium for Aspergillus fumigatus contained (g/l) NaNO3, 15; K2HPO4, 15; MgSO4, 5; FeSO4, 0.009; KCI, 0.5; peptone, 20; and yeast extract, 10.

Aspergillus fumigatus↗
PubMed1990

Streptococcus pneumoniae-stimulated macrophages induce neutrophils to emigrate by a CD18-independent mechanism of adherence.

Neutrophil adherence to and emigration across endothelium are in large part dependent upon the neutrophil membrane CD11/CD18 glycoprotein complex. Recently, however, we have demonstrated that some stimuli can elicit neutrophil emigration in the lung by a CD18-independent pathway. We examined further the mechanism involved in CD18-independent emigration in a rabbit model of inflamed peritoneum. Neutrophil emigration in the peritoneum induced by instillation of E. coli and S. pneumoniae was studied under four experimental conditions: Group 1--normal peritoneum, Group 2--peritoneum primed with protease peptone to increase the number of macrophages, Group 3--peritoneum treated by protease peptone instillation and then depleted of the increased macrophage population, and Group 4--peritoneum with macrophages transplanted from animals enriched as in Group 2. Experiments were run in pairs with animals in each group assigned to receive either saline (control) or monoclonal antibody (MAb) 60.3 prior to bacterial instillation in the peritoneum. Neutrophil emigration in response to E. coli was greater than 86% inhibited by MAb 60.3 in both the normal and the macrophage-enriched peritoneum. Neutrophil emigration in response to S. pneumoniae was inhibited greater than 85% in the normal peritoneum and the macrophage-enriched and the transplanted macrophage peritoneum. These data indicate that macrophages can augment PMN emigration by a non-CD18 mechanism, and may explain the increased sensitivity of organs with large resident macrophage populations, liver and lung, to injury following shock and sepsis.

Animals↗