scholarly journals Dose dependency of the effect of ornithine α-ketoglutarate on tissue glutamine concentrations and hypercatabolic response in endotoxaemic rats

2004 ◽  
Vol 92 (4) ◽  
pp. 627-634 ◽  
Author(s):  
Pascal Pernet ◽  
Colette Coudray-Lucas ◽  
Christina Schneid ◽  
Alain Jardel ◽  
Luc Cynober

The optimal dosage of ornithine α-ketoglutarate (OKG) for repleting tissue glutamine (Gln) concentrations and maintaining N homeostasis after injury is unknown. We set out to perform ‘dose-ranging’ of OKG supplementation after an endotoxaemic challenge. Sixty-one male Wistar rats were injected with 3 mg lipopolysaccharide (LPS) from Escherichia coli/kg (n 50) or saline vehicle (9 g NaCl/l; controls n 11). After a 24 h fast, survivors were fed by gavage for 48 h with a polymeric standard diet (879 kJ/kg per d and 1·18 g N/kg per d) supplemented with non-essential amino acids (control, n 11; LPS-OKG-0·0, n 9), or with 0·5 g OKG/kg per d (LPS-OKG-0·5, n 12), 1·5 OKG/kg per d (LPS-OKG-1.5, n 11) or 4·5 g OKG/kg per d (LPS-OKG-4·5, n 10). The diets for all groups were made isonitrogenous with the LPS-OKG-4·5 diet by adding an appropriate amount of non-essential amino acids. Rats were killed on day 3 for blood and tissue sampling (muscle, jejunum mucosa, liver). Urine was collected daily for 3-methylhistidine and total N assays. The OKG dose was correlated with Gln concentrations in every tissue and with cumulative N balance (Spearman test, P<0·01). 3-Methylhistidine excretion was increased in endotoxaemic groups compared with controls (ANOVA, P<0·05) except in the LPS-OKG-4·5 group. Only the LPS-OKG-4·5 group achieved a positive post-injury N balance (t test, P<0·05). In conclusion, OKG exerted a dose-dependent effect on tissue Gln concentration and N balance, but only the highest dosage counteracted myofibrillar hypercatabolism and caused a positive N balance.

2018 ◽  
Vol 26 (1) ◽  
pp. 65-75
Author(s):  
Simona Ifrim ◽  
Cornelia Amalinei ◽  
Elena Cojocaru ◽  
Mioara Calipsoana Matei

Abstract Hypercholesterolemia has a major contribution to the occurrence and progression of atherosclerotic lesions. Recent studies report the involvement of branched-chain amino acids in cholesterol methabolism. The aim of this research was to evaluate the role of valine, leucine and isoleucine on the occurrence and progression of atherosclerosis in rats receiving hypercholesterolic diet. Material and methods: 50 male Wistar rats distributed into five groups with the following type of diets: group I (control) received standard diet; group II - cholesterol; group III - cholesterol and valine; group IV - cholesterol and leucine; group V - cholesterol and isoleucine. The experimental study was conducted over a period of 2 months. The animals were evaluated for the serum levels of total cholesterol at the beginning of the experiment, after 1 month and after 2 months. The collected tissue fragments of heart and aorta were prepared for the examination by optical microscopy in order to identify the atherosclerotic changes. Results: The most increased values of serum cholesterol were recorded in rats from group II (p=0.001), for the second and third evaluation. The histological examination showed early histopathological lesions on the vascular intima for the groups treated with cholesterol, valine, leucine, and isoleucine. These early changes (the occurrence of some superficial endothelial erosions, adhesion of erythrocytes and platelets) were correlated with the degree of the arterial wall damage, of the leukocytes adhesion to the arterial intima, and the discontinuities of the internal elastic lamina. Conclusion: The comparative study of the effects of the three essential amino acids revealed that valine induced a faster response than leucine and isoleucine on the improvement of biochemical parameters, but there were no significant differences between the three amino acids in terms of their protective ability, demonstrated by the histopathological lesion assessment.


1985 ◽  
Vol 54 (2) ◽  
pp. 499-508 ◽  
Author(s):  
J. Heger ◽  
Z. Frydrych

1. Nitrogen balance was studied in growing male SPF-rats fed on diets in which each essential amino acid was varied from zero to about 120% of optimum requirement. From the balance results, optimum and maintenance requirements were estimated as well as the efficiency of utilization of amino acids for growth and growth + maintenance.2. N balance increased with increasing dietary level of the deficient amino acid; the response gradually diminished as the content of the amino acid approached optimum. At zero level of intake, negative N balance was found for all amino acids except histidine. The highest loss of body N was found in the sulphur-amino-acid-free diet and the lowest one in the lysine-free diet.3. Maximal utilization of essential amino acids for growth was found at dietary levels corresponding to 30–60% of optimum requirement and ranged from about 0.65 to 0.85 except for S amino acids and histidine. The utilization of S amino acids was about 0.55 while that of histidine exceeded 1.0. The utilization of amino acids for growth-tmaintenance was maximal at the lowest levels of intake and gradually decreased as the dietary concentration of the limiting amino acid increased. At dietary levels near optimum the utilization was about 06–07, except for S amino acids where the utilization was less than 0.5.


1993 ◽  
Vol 57 (2) ◽  
pp. 237-245 ◽  
Author(s):  
J. C. MacRae ◽  
A. Walker ◽  
D. Brown ◽  
G. E. Lobley

AbstractTwelve Suffolk-Finn Dorset lambs were reared from 25 to 40 or 25 to 55 kg body weight on either pelleted dried grass or a ration of pelleted grass plus barley (ratio 1:1) in a comparative slaughter experiment designed to determine the amounts of total nitrogen and individual amino acids accreted in different body components during growth. Nitrogen (N) balance measurements were determined frequently during this growth phase and accumulated N retentions were compared with the total N accretion determined by comparative slaughter. Total N and individual amino acids accumulated in carcass, wool, skin, offal and blood, head and feet, gastro-intestinal tract and liver were linearly related to body weight in all cases other than for cysteine in carcass. At 25 kg live weight, proportionately 0·52 of total body N was in carcass components, 0·115 in wool, 0·08 in skin, 0·10 in offal and blood, 0·095 in head and feet, 0·06 in the gastro-intestinal tract and 0·02 in liver. However as the animals grew from 25 to 55 kg, 0·256 of the total N accretion was in wool, which was rich in cysteine (98 g/kg total amino acid). Carcass accretion represented only 0·449 of total body N accretion. The N balance technique overestimated net protein accretion by 0·24 (s.e. 0·036).


1982 ◽  
Vol 62 (1) ◽  
pp. 259-267 ◽  
Author(s):  
L. E. PHILLIP ◽  
J. G. BUCHANAN-SMITH

In a replicated 2 × 2 double latin square, 16 lambs were fed whole-plant corn harvested at 26% or 38% dry matter (DM) and either ensiled or frozen. Corn was supplemented with urea (1.25%, DM basis). Voluntary intake was measured during a 17-day period of ad libitum feeding, after which the lambs were restricted on feed (65 g DM/Wkg0.75) for 14 days for the determination of nitrogen (N) balance and digestibility. Ensiling resulted in an increase in nonprotein nitrogen (NPN), mainly as amino acid-N, from 21% to 48% of the total N in the low DM corn, and from 25% to 43% in the high DM corn. Basic and acidic amino acids were selectively degraded during ensilage. Amine-N accounted for less than 5% of total N in the silages. Voluntary intake (g DM/Wkg0.75) of ensiled corn was not significantly different from that of frozen corn (77.3 vs. 81.7) but was higher (P < 0.05) for the low DM than the high DM corn (85.1 vs. 73.9). Estimates of N balance and digestibility of DM and organic matter were not affected (P < 0.05) by ensiling or by stage of harvest. There appears to be no adverse effect of ensiling whole-plant corn on its voluntary intake and N utilization by ruminants, provided the silage is supplemented with urea. Key words: corn, ensiling, intake, Digestibility, ruminants, nonprotein nitrogen


2022 ◽  
Author(s):  
Berra Erkosar ◽  
Cindy Dupuis ◽  
Fanny Cavigliasso ◽  
Loriane Savary ◽  
Hector Gallart-Ayala ◽  
...  

Juveniles are often first to suffer from nutrient shortage, and juvenile undernutrition is likely an important force of natural selection shaping animal physiology, with consequences potentially extending into adulthood. We combined RNAseq, targeted metabolomics and genomics to study the consequences of experimental evolution under juvenile undernutrition for metabolism of reproductively active adult females of Drosophila melanogaster. Compared to six Control populations maintained on standard diet, six Selected populations evolved for over 230 generations on a nutrient-poor larval diet showed major changes in adult gene expression and metabolite abundance. In particular, Selected flies were relatively deficient in essential amino acids and purine nucleotides, but showed overabundance of several non-essential amino-acids involved in purine synthesis and overexpression of multiple enzymes catalyzing this pathway. Selected flies also accumulated medium-chain acylcarnitines suggestive of congestion in beta-oxidation, possibly linked to deficiency of electron transporters. Some aspects of the metabolic profile of Selected flies resembled that of flies subject to starvation. Furthermore, differences between Selected and Control populations in adult gene expression were in general positively correlated with differences in larval expression, consistent with pleiotropy in gene regulation between the life stages. Finally, Selected flies were less fit in terms of fecundity than Controls even when both were raised under the conditions under which the Selected populations evolved. These results suggest that evolutionary adaptation to juvenile undernutrition has large pleiotropic consequences for adult metabolism, and that they are costly rather than adaptive for adult fitness.


1974 ◽  
Vol 31 (2) ◽  
pp. 125-142 ◽  
Author(s):  
D. Ben-Ghedalia ◽  
H. Tagari ◽  
A. Bondi ◽  
A. Tadmor

1. The rate of flow of digesta along the intestinal tract, and particularly the changes occurring in proteins during their passage through the intestine were determined in six rams; each animal was fistulated with three cannulas which involved six different sites of the intestine. Cr2O3 was used as a marker substance to measure the rate of flow of the digesta.2. In the sections of the intestine from 1 to 15 m posterior to the pylorus the amounts of water, dry matter and total nitrogen decreased gradually as a result of their absorption through the intestinal wall. The region of the intestine situated at a distance of 7–15 m from the pylorus was more active with respect to the absorption of N, whereas water and dry matter were adsorbed to a greater extent in the region from 1 to 7 m from the pylorus.3. The only part of the intestine in which substantial increases of water, dry matter and total N were found was the section immediately distal to the pylorus, and these increases were caused by the inflow of bile, and pancreatic and duodenal juices. The net increase found beyond the entry of the common bile duct was 2.7 g protein N and 2.0 g non-protein N (NPN)/24 h.4. The activities of trypsin, chymotrypsin and carboxypeptidase A and the ratio α-NH2 NPN: protein N increased from the pylorus up to a distance of 7 m and decreased again from this point to a distance of 15 m from the pylorus.5. In the sections of the intestine between 1 and 3 and between 3 and 7 m distant from the pylorus the extent of proteolysis exceeded considerably that of absorption of amino acids through the intestinal wall. This was concluded from the decrease in the rate of flow of protein amino acids (by 31% between 1 and 3 m distant from the pylorus and by 34% between 3 and 7 m) and the simultaneous increase in non-protein amino acids (by 20% in the region between 1 and 3 m) or no change in non-protein amino acids (between 3 and 7 m).6. The relatively greater decrease in non-protein amino acids (by 57%) compared with that of protein amino acids (by 41%) occurring in the section 7 to 15 m distant from the pylorus showed that this is an area of most intensive absorption of amino acids.7. In the lower section of the intestine, from 15 to 25 m distant from the pylorus, the total amount of amino acids showed almost no change; probably a net effect of loss and gain of amino acids mainly due to microbial activities. Increases in the dehydrogenase activity suggested enhancement of bacterial activity in this lower region of the intestine.8. The supply of essential amino acids to the tissues of sheep is improved, compared with the amino acid composition of the diet, as the result of ruminal biosynthesis of essential amino acids and ruminal degradation of non-essential amino acids and preferential absorption of essential amino acids through the intestinal wall, particularly in the section of most intensive absorption, 7–15 m distant from the pylorus.


Medicina ◽  
2021 ◽  
Vol 57 (3) ◽  
pp. 239
Author(s):  
Elena Cojocaru ◽  
Maria Magdalena Leon-Constantin ◽  
Carmen Ungureanu ◽  
Mioara Florentina Trandafirescu ◽  
Alexandra Maștaleru ◽  
...  

Background and Objectives: Considering atherosclerosis as one of the more challenging threats to healthcare worldwide, any novel therapy that counteracts the risks for developing it, provides new opportunities for the management of this process. Material and methods: We performed an experimental research in which we induced a hypercholesterolemia via a cholesterol-rich diet. Our aim was to demonstrate the antiatherogenic potential of two essential amino acids (valine and leucine). The experimental study was carried out over a period of 60 days. Male Wistar rats weighing between 250–280 g were used and divided into 4 groups, each group including 8 animals. Group I—control was fed with a standard diet. Group II received cholesterol, group III cholesterol and valine and group IV cholesterol and leucine. Blood samples were collected from the retro-orbital plexus, under anesthesia with 75 mg/kg of intraperitoneal ketamine, in three different moments (R0—1st day, R1—the 30th day, R2—the 60th day) in order to measure the levels of triglycerides. Results: In R0, there were no significant differences between the average levels of triglycerides across all the groups (p < 0.05). Compared to the group I, in R1 and R2, the average levels of triglycerides were significantly higher in all groups (p < 0.001). Also, in R1 and R2, the average triglycerides in group II receiving cholesterol (C) were significantly higher than those in group III receiving valine (C + V) as well as in group IV receiving leucine (C + L) (p < 0.001; p < 0.05). In R2, the average triglycerides in group III were significantly lower than in group IV (p < 0.001). Conclusions: Our data provides evidence that valine and leucine have a direct impact on the lipid metabolism parameters by lowering the level of triglycerides. The comparison of the two essential amino acids indicates that valine acts more promptly and rapidly than leucine.


1976 ◽  
Vol 36 (2) ◽  
pp. 199-209
Author(s):  
A. P. Williams ◽  
R. H. Smith

1. Calves were given a basal diet of straw and flaked maize (12 g nitrogen/kg dry matter (DM)) or diets with some flaked maize replaced by untreated (UT) casein or formaldehyde-treated (FT) casein to give 19, 26 or 34 g N/kg DM.2. At all intakes rumen ammonia concentrations were lower and amounts of total-N, non-ammonia-N and amino acid-N entering the duodenum were higher when FT-rather than UT-casein supplements were given.3. Direct measurement of casein entering the duodenum indicated that giving FT rather than UT casein led to much greater amounts of dietary casein escaping degradation in the rumen (70–90% compared to 10–20%). Calculated values for fermentable N indicated that with this low degradability diets containing FT-casein would have provided inadequate N for maximum microbial synthesis in the rumen, and this probably accounted for the marked reduction in amounts of non-casein-N entering the duodenum when FT rather than UT casein was given.4. Amino acid patterns in duodenal digesta samples after giving the basal diet or diets containing UT-casein were similar. Giving diets containing FT-casein led to changes in this pattern which could sometimes, although not always, be accounted for by estimated differences in proportions of dietary and microbial proteins.5. At the highest level of N intake FT-casein-supplemented diets led to significantly higher concentrations of most essential amino acids and lower concentrations of most non-essential amino acids in plasma than did UT-casein-supplemented diets. Plasma urea concentrations increased with increasing N intake but were not significantly different for UT- and FT-casein-supplemented diets.


2019 ◽  
Author(s):  
Weronika Czaban ◽  
Jim Rasmussen

AbstractDirect plant uptake of organic nitrogen (N) is important for plant N nutrition, but we lack knowledge of how the concentration of external N forms (organic and inorganic) -influence organic N uptake and plant N status. We investigated the uptake of the amino acid asparagine (Asn) in white clover in the presence of different nitrate (NO3-), Asn, and total N concentrations. White clover seedlings were for one week exposed to combinations of NO3-(3-30 µmol N kg-1sand DW) and Asn (3-30 µmol N kg-1sand DW), where after the Asn uptake rate was determined by addition of13C4-Asn. Shoot and root Asn content and amino acid profiles were also analyzed. Increasing external NO3-and total N concentrations decreased13C4-Asn uptake rates and internal clover Asn content. Furthermore, total N affected clover amino acid profiles from non-essential amino acids at low N doses to the dominance of essential amino acids at increasing N doses. Asn uptake rate in white clover is reduced by increasing inorganic N, but not by increasing organic N concentrations. Furthermore, plant amino acid profiles are likely to be a more sensitive indicator of N supply and descriptor of the N status.


1974 ◽  
Vol 54 (3) ◽  
pp. 305-313 ◽  
Author(s):  
H. R. SHARMA ◽  
J. R. INGALLS ◽  
R. J. PARKER

Four Holstein steers fitted with T-type soft plastic cannulae in the rumen, abomasum and terminal ileum were fed four semipurified pelleted diets containing 19% rapeseed meal (RSM) or 7.5% casein, both untreated or treated with formaldehyde (FA), during the four experimental periods. The diets were fed from an automatic belt feeder device. FA treatment of casein increased (P < 0.01) the flow of total N and non-ammonia-N (NAN) as a percentage of intake through the abomasum of steers. Significantly more (P < 0.05) bacterial N passed through the abomasum of steers fed RSM diets than those receiving the casein diets. FA treatment caused a nonsignificant (P > 0.05) depression in the apparent digestibility of dry matter (DM) in the small intestine of steers receiving the treated diets. Significantly greater (P < 0.05) quantities of total N and NAN passed through the terminal ileum of steers consuming the RSM diets compared to those fed casein diets. Total determined amino acids in the abomasum as a percentage of amino acid intake were lower (P < 0.01) for untreated casein diet compared to the other three treatments. FA treatment increased (P < 0.05) the flow of lysine, histidine, valine, isoleucine, leucine and tyrosine in the abomasum of steers receiving FA casein compared with untreated casein, but had no effect in the case of treated RSM. FA treatment increased the absorption of most of the essential amino acids in the small intestine of steers receiving the FA casein compared to casein diet. Treatment of RSM resulted in reduced (P < 0.05) fecal excretion of threonine, valine, isoleucine, leucine, phenylalanine and tyrosine.


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