Nitrogen metabolism in the ovine stomach: 2. Factors influencing ruminal ammonia levels in sheep maintained on different diets

1974 ◽  
Vol 82 (3) ◽  
pp. 409-417 ◽  
Author(s):  
C. J. F. Harrop
Keyword(s):  
Nitrogen Metabolism ◽  
Urease Activity ◽  
Ammonia Concentration ◽  
Maximum Activity ◽  
Ammonia Production ◽  
Cellulolytic Bacteria ◽  
Ruminal Fluid ◽  
Factors Influencing

SUMMARYFactors which could be expected to influence levels of ammonia in the rumen were compared in sheep maintained on diets providing 11·4 or 20·7 g N/day.The ruminal fluid volume in sheep given the lower-N ration was 78% of that in sheep maintained on the higher-N diet. The effect of this in diluting rumen ammonia from recycled urea is discussed.Ruminal urease activity was higher in sheep given the lower-N diet, and was confined to the particulate fraction of rumen liquor in animals given either diet. At least 95% of the maximum activity occurred in the range of pH 5·4–7·05, and pH 6·0–7·25 in sheep maintained on the lower- and higher-N diets respectively. Small variations in activity were observed between the morning and evening meals.In vitro rates of net ammonia production in samples of rumen liquor were similar in sheep given either diet; a positive correlation with the initial ammonia concentration was evident. Net utilization of ammonia was detected in some experiments in samples from sheep maintained on the lower-N diet. Starvation for 1 day was associated with increased rates of production and initial concentrations of ammonia.Cellulose, as cotton thread, was digested at similar rates in vivo in sheep given the different diets. This is discussed in relation to the demand for ammonia by cellulolytic bacteria.

Intestinal Ammonia in Uraemia: The Effect of a Urease Inhibitor, Acetohydroxamic Acid

1972 ◽  
Vol 42 (1) ◽  
pp. 105-112 ◽  
Author(s):  
J. D. Swales ◽  
J. D. Tange ◽  
D. J. Evans
Keyword(s):  
Treated Group ◽  
Ammonia Concentration ◽  
Total Serum Protein ◽  
Total Serum ◽  
Acetohydroxamic Acid ◽  
Urease Inhibitor ◽  
Ammonia Production ◽  
Ammonia Content

1. The effects of intestinal ammonia in uraemia have been studied by administering a urease inhibitor, acetohydroxamic acid, to bilaterally nephrectomized rats. 2. Ammonia concentration was significantly decreased in the colon although it remained slightly higher than in normal animals. Caecal ammonia concentration was not altered. Total ammonia content was decreased in both colon and caecum. 3. A study in vitro indicated that ammonia production could be totally inhibited by acetohydroxamic acid. This suggests that the failure to suppress ammonia production in vivo is due to failure of the inhibitor to reach the site of urease production in sufficient concentration. 4. The animals treated with high doses of acetohydroxamic acid survived for a shorter time. Blood urea was higher and total serum protein lower in the treated group. The incidence of colitis was not affected.

ATP turnover and renal response of dog tubules to pH changes in vitro

1986 ◽  
Vol 251 (5) ◽  
pp. F919-F932
Author(s):  
C. Manillier ◽  
P. Vinay ◽  
L. Lalonde ◽  
A. Gougoux
Keyword(s):  
Respiratory Acidosis ◽  
Maximum Activity ◽  
Tissue Response ◽  
Proximal Tubules ◽  
Glutamine Metabolism ◽  
Ammonia Production ◽  
Atp Turnover ◽  
Dog Kidney

In vivo the dog kidney responds to metabolic or respiratory acidosis by a marked increment of its ammonia production (expressed per 100 milliliters glomerular filtration rate). This phenomenon is related to a switch from metabolic utilization of nonammoniagenic (lactate) to ammoniagenic (glutamine) substrates to support ATP turnover in the proximal tubules. We have proposed that in vivo the maximum activity of the ammoniagenic process is fixed by the ATP turnover in this segment of the nephron. The maximal glutamine metabolism is reached when 100% of this turnover is supported by glutamine metabolism. We have studied how these concepts apply to the adaptation of glutamine metabolism and ammonia production to a low pH in vitro using proximal tubules of dogs incubated when one (lactate or glutamine) or several (glutamine plus lactate or plus palmitate) substrates are provided. At pH 7.4 glutamine alone supports already 71-76% of the tissue ATP turnover (minimal and maximal values). With acidification this fraction rises to nearly 87-94%, but this increases only modestly the ammonia production. Reducing the ATP turnover with ouabain at pH 7.4 decreases the absolute glutamine utilization, which now supports only 45-50% of the ATP turnover. Again acidification increases this fraction to 90-99%. Addition of lactate with glutamine displaces part of the glutamine metabolized, but greatly stimulates the synthesis of alanine. Fatty acids depress ammonia production and blunt the tissue response to acidification. Gluconeogenesis from lactate is minimally influenced by incubation pH. It is concluded that the ATP turnover limits the metabolism of glutamine by proximal tubules in vitro as in vivo in the dog, and that the response to acidification is small in vitro because of the absence of alternative substrates.

scholarly journals Effect of a Rumen-Protected Microencapsulated Supplement from Linseed Oil on the Growth Performance, Meat Quality, and Fatty Acid Composition in Korean Native Steers

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1253
Author(s):  
Chae-Hyung Sun ◽  
Jae-Sung Lee ◽  
Jalil Ghassemi Nejad ◽  
Won-Seob Kim ◽  
Hong-Gu Lee
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Growth Performance ◽  
Meat Quality ◽  
Acid Composition ◽  
Linseed Oil ◽  
Control Group ◽  
Ruminal Fluid

We evaluated the effects of a rumen-protected microencapsulated supplement from linseed oil (MO) on ruminal fluid, growth performance, meat quality, and fatty acid composition in Korean native steers. In an in vitro experiment, ruminal fluid was taken from two fistulated Holstein dairy cows. Different levels of MO (0%, 1%, 2%, 3%, and 4%) were added to the diet. In an in vivo experiment, eight steers (average body weight = 597.1 ± 50.26 kg; average age = 23.8 ± 0.12 months) were assigned to two dietary groups, no MO (control) and MO (3% MO supplementation on a DM basis), for 186 days. The in vitro study revealed that 3% MO is an optimal dose, as there were decreases in the neutral detergent fiber and acid detergent fiber digestibility at 48 h (p < 0.05). The in vivo study showed increases in the feed efficiency and average daily gain in the 3% MO group compared to the control group on days 1 to 90 (p < 0.05). Regarding meat quality, the shear force produced by the longissimus thoracis muscle in steers from the 3% MO group was lower than that produced by the control group (p < 0.05). Interestingly, in terms of the fatty acid profile, higher concentrations of C22:6n3 were demonstrated in the subcutaneous fat and higher concentrations of C18:3n3, C20:3n3, and C20:5n3 were found in the intramuscular fat from steers fed with 3% MO (p < 0.05). Our results indicate that supplementation with 3% MO supplements improves the growth performance and meat quality modulated by the omega-3 fatty acid content of meat in Korean native steers.

scholarly journals ANTIULCER ACTIVITY OF CONTROLLED RELEASE FORMULATION CONTAINING AQUEOUS EXTRACT OF ACACIA CATECHU WILLD ON RODENT MODELS

2018 ◽  
Vol 10 (5) ◽  
pp. 25
Author(s):  
Basant Khare ◽  
Naina Dubey ◽  
Akash Sharma
Keyword(s):  
Controlled Release ◽  
Aqueous Extract ◽  
Maximum Activity ◽  
Antiulcer Activity ◽  
Rodent Models ◽  
Ulcer Index ◽  
Release Formulation ◽  
Acacia Catechu

Objective: To study the Antiulcer activity of aqueous extract of acacia catechu willd on rodent models by controlled release formulation.Methods: Microspheres were prepared by solvent evapoaration method and were evaluated for various parameters like SEM, stability and in vitro relese. And acacia catechu willd loaded microspheres were evaluated for in vivo study involving Gastric ulceration in rats was induced by Ethanol/HCl. Ulcer genic effect (Ulcer Index), pH and Total acidity, Histopathological studies.Results: Results indicated that Acacia catechu willd microspheres contains some active constituents like flavanoid which are responsible for its anti ulcer activity. Also it was observed aqueous extract loaded microspheres showed maximum activity was found (200 mg/kg) with standard Cimetidine (100 mg/kg) also, the results revealed that aqueous extract microspheres at 200 mg/kg had reduced ulcer incidence significantly, when compared to the control as evident by decrease in ulcer score in the model.Conclusion: Based on the result it can be concluded that microspheres loaded with aqueous extracts of Acacia catechu willd produced promising antiulcer activity and were safe.

scholarly journals Anticancer Activity of Andrographolide Semisynthetic Derivatives

2010 ◽  
Vol 5 (5) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Vidya Menon ◽  
Sujata Bhat
Keyword(s):  
Breast Cancer ◽  
Antitumor Activity ◽  
Myeloid Leukemia ◽  
Cancer Cell Line ◽  
Maximum Activity ◽  
In Vitro Activity ◽  
Cancer Models ◽  
In Vivo Antitumor Activity

Andrographolide 1, a diterpene lactone of Andrographis paniculata, displays in vitro and in vivo antitumor activity against breast cancer models and mouse myeloid leukemia (M1) cells. In the present study, we report the semi-synthesis of andrographolide derivatives and their in vitro activity against A549 (ATCC) (NSCL cancer) cell line. Amongst the derivatives tested, compounds 3- 5 displayed maximum activity, with IC50 values of 22-31 μg/mL.

Effect of potassium on ammoniagenesis by renal mitochondria

1976 ◽  
Vol 231 (1) ◽  
pp. 44-51 ◽  
Author(s):  
RL Tannen ◽  
AS Kunin
Keyword(s):  
Intact Animal ◽  
Absolute Magnitude ◽  
Ammonia Production ◽  
Critical Rate ◽  
Potassium Homeostasis ◽  
Effector Mechanism ◽  
Cortical Slices ◽  
Over Time

Ammonia production by rat renal cortical mitochondria was studied with both in vivo and in vitro manipulation of potassium to further elucidate the mechanisms relating potassium homeostasis and renal ammonia production. Mitochondria from potassium-depleted animals demonstrated an increase in ammonia production at all glutamine concentrations studied, which ranged from 0.5 to 10 mM. This increase in ammoniagenesis compared favorably in degree of change with and was of sufficient absolute magnitude to entirely account for the findings observed both in renal cortical slices studied in vitro and in the intact animal. When rotenone is added to the medium, increased ammoniagenesis is still detected, indicating that either glutamine entry into the mitochondria and/or the activity of phosphate-dependent glutaminase are critical rate-controlling steps. In contrast to studies with renal slices, a decrease in ammonia production was not apparent with cortical mitochondria from chronically potassium-loaded animals. In vitro alterations of the potassium homeostasis. Therefore, these experimental manipulations either do not activate an effector mechanism which takes place in vivo, or the alteration in ammoniagenesis requires an adaptation over time that is not achieved with this in vitro approach.

SOME GENETIC AND PHYSIOLOGICAL CHARACTERISTICS OF UREASE-DEFECTIVE STRAINS OF NEUROSPORA CRASSA

1971 ◽  
Vol 13 (2) ◽  
pp. 256-269 ◽  
Author(s):  
Philip Haysman ◽  
H. Branch Howe Jr.
Keyword(s):  
Linkage Group ◽  
Nitrogen Source ◽  
Urease Activity ◽  
Temperature Sensitive ◽  
Sole Nitrogen Source ◽  
Group V ◽  
Group I ◽  
Mutant Strains

Fourteen mutant strains have been isolated which differ from wild type with respect to urease activity: Seven strains lack detectable activity in vivo and in vitro, B1, C21 and allele 601, D1 and allele D3, D2, and W2, and fail to grow with urea as sole nitrogen source; seven have activity in vivo and varying amounts in vitro, A7, E3, E7, R2, S3, and temperature-sensitive strains C5 and K3. Strains D1 and D3 are allelic to Kolmark's ure-1; W2, to Kolmark's ure-2. Strain D2, which is either allelic or closely linked to ure-1, complements none of the strains lacking urease activity nor three of the strains having defective activity, and may be a regulatory mutant. Strains B1, C21 and allele 601 represent two previously unreported loci in linkage group I. Only two of the seven swains having defective urease activity have been mapped, A7 and S3, and have been assigned to linkage group V. These seven strains grow readily on Vogel's medium modified by having urea as sole nitrogen source but not on W-M medium similarly modified; growth is restricted on modified Vogel's medium as well, however, if the initial concentration of nitrogen, as urea, is suitably adjusted to exceed that of phosphorus.

Validation of lactose[15N,15N]ureide as a tool to study colonic nitrogen metabolism

2005 ◽  
Vol 288 (5) ◽  
pp. G994-G999 ◽  
Author(s):  
Karen P. Geboes ◽  
Vicky De Preter ◽  
Anja Luypaerts ◽  
Bert Bammens ◽  
Pieter Evenepoel ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
Nitrogen Metabolism ◽  
Proximal Colon ◽  
Fecal Excretion ◽  
In Vitro Experiments ◽  
Dietary Intakes ◽  
Nitrogen Pool ◽  
Different Types

In vitro experiments have shown that fermentation of carbohydrates prevents accumulation of nitrogen in the colon. Variable results have been obtained on modulation of dietary intakes in vivo. Lactose[15N,15N]-labeled ureide has been proposed as a tool to study colonic nitrogen metabolism. However, on oral administration of the marker, different urinary excretion patterns of the 15N label have been found. In this study, 50 mg lactose[15N,15N]ureide was directly instilled in the colon through an orocecal tube to investigate the colonic handling of this molecule in a direct way. In basal conditions, 42% (range, 37–48%) of labeled nitrogen administered as lactose[15N,15N]ureide was retrieved in urine after 72 h. A substantial variability in total urinary excretion of the label was found, but the urinary excretion pattern of the label was similar in all volunteers. When inulin, a fermentable carbohydrate, was administered together with the labeled marker, a significant decrease in urinary excretion of 15N after 72 h was found, to 29% (range, 23–34%). The effect of a smaller dose of inulin (250 mg) on colonic handling of lactose[15N,15N]ureide (50 mg), was investigated in another group of volunteers, and this time, fecal excretion of the marker was also evaluated. The results seem to indicate that fermentation of inulin causes an increased fecal excretion of the marker, thereby reducing urinary excretion but not retention in the human nitrogen pool. This instillation study shows that lactose[15N,15N]ureide is a tool with good properties to investigate the effect of different types of carbohydrates on nitrogen metabolism in the proximal colon in vivo.

EFFECT OF FORMALDEHYDE TREATMENT OF SOYBEAN MEAL ON RATES OF PROTEIN DEGRADATION AND MICROBIAL PROTEIN CONCENTRATION IN THE BOVINE RUMEN

1983 ◽  
Vol 63 (1) ◽  
pp. 181-190 ◽  
Author(s):  
S. MAHADEVAN ◽  
R. M. TEATHER ◽  
J. D. ERFLE ◽  
F. D. SAUER
Keyword(s):  
Soybean Meal ◽  
Latin Square ◽  
Experimental Period ◽  
Ammonia Concentration ◽  
Bovine Rumen ◽  
Rumen Degradation ◽  
Formaldehyde Treatment ◽  
Highly Correlated

Four rumen-fistulated cows were fed concentrate:corn silage (40: 60) diets in a 4 × 4 latin square design experiment. The diets differed in the soybean meal or soybean meal treated with 0.1, 0.3 or 0.6% (wt/wt) formaldehyde. Rumen contents were collected hourly from 0900 h to 1600 h with an additional sample at half an hour after the 1100 h feeding on 3 days in the second week of each 2-wk experimental period. The maximum ammonia concentration in rumen contents decreased with increasing levels of formaldehyde used to treat the soybean meal. From 1130 to 1200 h the rates of ammonia appearance in the rumen contents were different (P < 0.05) for all four diets. Treatment of soybean meal with between 0.1 and 0.3% (wt/wt) formaldehyde reduced its in vitro degradation by rumen protease by about 50% compared with the untreated control. The rates of in vivo ammonia appearance and in vitro proteolysis were highly correlated (r = 0.966, P < 0.01) between 1130 h and 1200 h. These rates of rumen ammonia appearance reflected the in vivo rate of proteolysis. Both bacterial and protozoal protein content decreased significantly at the higher levels of formaldehyde treatment. There was a negative correlation (r = − 0.63, P < 0.01) between protozoal and bacterial protein. Key words: Formaldehyde, soybean meal, bovine, rumen, degradation, protease

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