• Toxicological Research
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• 제9권1호
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• pp.45-60
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• 1993

The present study was carried out to evaluate the cytotoxicity of cadmium on cultured rat fibroblasts. The colorimetric assays of neutral red and tetrazolium MTT, the lactatedehydrogenase activity, the amounts of total protein, the rate of DNA synthesis, the amounts of unscheduled DNA synthesis, the frequency of sister chromatid exchange, the releasing rate of intracellular calcium, and light and electron microscopic studies were performed on cultured rat fibroblasts maintained in the media containing various concentrations of cadmium. The results were as follows: The neutral red(NR) and MTT values were decreased dose-dependently by cadmium, and the NR90, NR50, MTT90 and MTT50 values of cadmium were 0.2mM, 21.5mM, 1.0Mm and 60.0Mm, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제15권10호
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• pp.1439-1444
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• 2002

An objective of this study was to determine the effects of increasing contents of rumen undegradable protein (RUP) from formalin treated soy bean (FSBM) on rumen functions. Four rumen canulated non-lactating cows were randomly allocated to total mixed rations (TMR) containing different proportions of soy bean meal (SBM) and FSBM. Of rumen fermentation characteristics, concentrations of ruminal fluid ammonia and molar proportions of isoacids decreased with increasing contents of RUP in diets (p<0.01). The animals on TMR containing only SBM gained less weight and had smaller rumen volume than those on TMR containing RUP from FSBM (p<0.05). Organic matter and neutral detergent fiber digestibility in sacco were not different (p>0.05). The density of protozoa particularly small Entodinium sp. in ruminal fluid was higher in animal fed TMR containing SBM:FSBM (34:66) and FSBM than those fed TMR containing SBM:FSBM (66:34) and SBM (p<0.01). Total viable count, and net microbial protein synthesis as indicated by purine derivatives in urine increased with increasing contents of RUP from FSBM (p<0.01). It can be concluded that a reduction in net microbial protein synthesis in the rumen with increasing contents of RUP in the diet can be due to the reduction of preformed protein available for microbial growth as well as an increased turnover rate of microbial cells by predatory activity of protozoa.

• Asian-Australasian Journal of Animal Sciences
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• 제27권5호
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• pp.667-673
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• 2014

Eight multiparous Holstein cows ($632{\pm}12$ kg BW; $135{\pm}16$ DIM) were used in a replicated $4{\times}4$ Latin square design to evaluate the effects of forage sources on rumen fermentation characteristics, performance, and microbial protein (MCP) synthesis. The forage portion of the diets contained alfalfa hay (AH), oat hay (OH), Leymus chinensis (LC), or rice straw (RS) as the primary source of fiber. Diets were isonitrogenous and isocaloric, and cows were fed four corn silages based total mixed rations with equivalent nonfiber carbohydrate (NFC) and forage neutral detergent fiber (NDF). Dry matter intake was not affected by the source of dietary forages, ranging from 18.83 to 19.20 kg/d, consequently, milk yield was similar among diets. Because of the numerical differences in milk fat and milk protein concentrations, 4% FCM and ECM yields were unchanged (p>0.05). Mean rumen pH, NH3-N content, and concentrations of volatile fatty acids in the rumen fluid were not affected by the treatments (p>0.05). Dietary treatments did not affect the total tract apparent digestibility of dry matter, organic matter, and crude protein (p>0.05); however, digestibility of NDF and acid detergent fiber in RS diet was higher compared with AH, OH, and LC diets (p<0.05). Total purine derivative excretion was higher in cows fed AH, OH, and LC diets compared with those fed RS diet (p<0.05), consequently, estimated MCP synthesis was 124.35 g/d higher in cows fed AH diet compared with those fed RS diet (p<0.05). The results indicated that cows fed AH, OH, LC, and RS diets with an equivalent forage NDF and NFC have no unfavourable effect on the ruminal fermentation and productive parameters.

• Nutritional Sciences
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• 제3권2호
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• pp.57-65
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• 2000

Partial enteral nutrition (PEN) supplemented with insulin-like growth factor-I (IGF-I) to neonatal piglets receiving parenteral nutrition increases lactase-phlorizin hydrolase (LPH) activity, but not LPH mRNA. The goal of the current study was to investigate the mechanism by which IGF-I up-regulates LPH activity. We hypothesized that IGF-I regulates LPH synthesis post-transcriptionally. Methods: Newborn piglets (n=15) received 100% parenteral nutrition (TPN), 80% parenteral nutrition + 20% PEN (PEN), or PEN + IGF-I (1.0mg/kg/d). On day 7, two stable isotopes of leucine, [$^2 H_3$]-leucine and [$^{13}C_1$]-L-leucine were intravenously administered to measure mucosal protein and brush LPH (BB LPH) synthesis. Results: Weight gain, nutrient intake and jejunal weight and length were similar among the treatment groups. PEN increased mucosal weight, villus width and cross-sectional area, LPH activity, mRNA expression and the abundance of proLPHh compared to 100% TPN (p<0.05). IGF-I further increased mucosal weight, LPH activity and LPH activity per unit BB LPH ~2-fold over PEN alone (p<0.05), but did not affect LPH mRNA or the abundance of proLPHh or mature LPH. Isotopic enrichment of [$^2 H_3$]-leucine and [$^{13}C_1$]-L-leucine in plasma, mucosal protein and LPH precursors, and the fractional and absolute synthesis rates of mucosal protein and LPH were similar among the treatment groups. Total mucosal protein synthesis was increased 60% (p<0.05) and LPH synthesis tended (p=0.14) to be greater in the IGF-I treated animals compared to the other two groups. Conclusions: The primary mechanism by which IGF-I up-regulates LPH may be post-translational, either via reducing LPH turnover, or by specifically altering LPH activity.

• Asian-Australasian Journal of Animal Sciences
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• 제23권11호
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• pp.1455-1461
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• 2010

Three rumen-cannulated Holstein steers were fed three diets, each with a different synchrony index (SI) (LS: 0.77, MS: 0.81, and HS: 0.83), in order to examine the effect of diet on rumen fermentation, nitrogen balance, and microbial protein synthesis. Synchrony index was calculated based on the carbohydrate and crude protein fractions of each ingredient and their degradation rates. Feeding the steers diets with different SIs did not influence dry matter, crude protein, NDF, or ADF digestibility. The concentrations of total and individual VFA in the rumens of steers that were fed the two higher-SI diets were higher than in those fed the low-SI diet (p<0.05), but there was no significant difference between the two higher-SI diets. One hour after feeding, steers on the LS diet had lower ruminal pHs than did those fed the MS or HS diets (p<0.05), and animals on the LS diet generally showed higher ruminal $NH_3$-N levels than did animals on the other diets, with the 4-h post-feeding difference being significant (p<0.05). Steers receiving the LS diet excreted more nitrogen (N) in their urine than did those on the two higher-SI diets (p<0.05), and the total N excretion of those on the LS diet was also higher (p<0.05). Microbial N levels calculated from the concentration of urinary purine derivatives were generally higher when the SI was higher, with the highest microbial protein synthesis being produced by steers on the HS diet (p<0.05). In conclusion, in the current study, ingestion of a synchronous diet by Holstein steers improved microbial protein synthesis and VFA production and decreased total N output.

• Journal of Animal Science and Technology
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• 제64권3호
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• pp.481-499
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• 2022

This study aims to determine the effects of D-methionine (D-Met) isomer and the methionine precursor 2-hydroxy-4-methylthiobutanoic acid i (HMBi) supplementation on milk protein synthesis on immortalized bovine mammary epithelial cell (MAC-T). MAC-T cells were seeded using 10-cm dishes and cultured in Dulbecco's modified Eagle's medium/F12 (DMEM/F12) basic medium. The basic medium of DMEM/F12 was replaced with the lactogenic DMEM/ F12 differentiation medium when 90% of MAC-T cells reached confluency. The best dosage at 0.6 mM of D-Met and HMBi and incubation time at 72 h were used uniformly for all treatments. Each treatment was replicated six times wherein treatments were randomly assigned in a 6-well plate. Cell, medium, and total protein were determined using a bicinchoninic acid protein assay kit. Genes, proteomics and metabolomics analyses were also done to determine the mechanism of the milk protein synthesis pathway. Data were analyzed by two-way analysis of variance (ANOVA) with supplement type and plate as fixed effects. The least significant difference test was used to evaluate the differences among treatments. The HMBi treatment group had the highest beta-casein and S6 kinase beta-1 (S6K1) mRNA gene expression levels. HMBi and D-Met treatments have higher gene expressions compared to the control group. In terms of medium protein content, HMBi had a higher medium protein quantity than the control although not significantly different from the D-Met group. HMBi supplementation stimulated the production of eukaryotic translation initiation factor 3 subunit protein essential for protein translation initiation resulting in higher medium protein synthesis in the HMBi group than in the control group. The protein pathway analysis results showed that the D-Met group stimulated fructose-galactose metabolism, glycolysis pathway, phosphoinositide 3 kinase, and pyruvate metabolism. The HMBi group stimulated the pentose phosphate and glycolysis pathways. Metabolite analysis revealed that the D-Met treatment group increased seven metabolites and decreased uridine monophosphate (UMP) production. HMBi supplementation increased the production of three metabolites and decreased UMP and N-acetyl-L-glutamate production. Taken together, D-Met and HMBi supplementation are effective in stimulating milk protein synthesis in MAC-T cells by genes, proteins, and metabolites stimulation linked to milk protein synthesis.

• Journal of Periodontal and Implant Science
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• 제26권3호
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• pp.669-679
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• 1996

Gingival overgrowth is a well known side effect of several drugs, including nifedipine, phenytoin, cyclosporin, dilitiazem, verapamil. A number of studies have been performed to investigate the mechanism by which nifedipine(a calcium channel blocking agent) affects the gingival tissue. The aim of the present work was to investigate the effect of nifedipine on healthy gingival fibroblasts with special emphasis on determining the changes in cellular proliferation and protein and collagen synthesis. Gingival fibroblasts were obtained from the explants of healthy gingiva of extracted 3rd molars or premolar teeth extracted from the patients for orthodontic treatment. To evaluate the effect of nifedipine on cell proliferation, the cells were seeded at a cell density of $1{\times}10^4$cells/well in 24-well culture plates and treated with 100 and 200ng/ml of nifedipine for 10days. After trypsinization, the cells were counted with a haemocytometer on 1st, 3rd, 5th, 7th and 10th days. Then, MTT assay was carried out. For total protein and percent collagen synthesis, $3{\mu}Ci/ml$ $^3H-proline$ was added to each well for the final 4 hours of the incubation period. The results indicate that nifedipine does not influence cell proliferation in healthy gingival fibroblast in vitro and has a specific effect in reducing total protein and percent collagen synthesis. On the above the findings, exogenous nifedipine does not influence on healthy human gingival fibroblast proliferation and protein and collagen synthesis.

• Asian-Australasian Journal of Animal Sciences
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• 제26권12호
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• pp.1689-1697
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• 2013

This study was designed to determine the effect of physical form and urea treatment of rice straw on rumen fermentation, microbial protein synthesis and nutrient digestibility. Four rumen-fistulated dairy steers were randomly assigned according to a 2 (2 factorial arrangement in a 4 (4 Latin square design to receive four dietary treatments. Factor A was roughage source: untreated rice straw (RS) and urea-treated (3%) rice straw (UTRS), and factor B was type of physical form of rice straw: long form rice straw (LFR) and chopped (4 cm) rice straw (CHR). The steers were offered the concentrate at 0.5% body weight (BW) /d and rice straw was fed ad libitum. DM intake and nutrient digestibility were increased (p<0.05) by urea treatment. Ruminal pH were decreased (p<0.05) in UTRS fed group, while ruminal ammonia nitrogen ($NH_3$-N) and blood urea nitrogen (BUN) were increased (p<0.01) by urea treatment. Total volatile fatty acid (VFA) concentrations increased (p<0.01) when steers were fed UTRS. Furthermore, VFA concentrations were not altered by treatments (p>0.05), except propionic acid (C3) was increased (p<0.05) in UTRS fed group. Nitrogen (N) balance was affected by urea treatment (p<0.05). Microbial protein synthesis (MCP) synthesis were greater by UTRS and CHR group (p<0.05). The efficiency of microbial N synthesis was greater for UTRS than for RS (p<0.05). From these results, it can be concluded that using the long form combined with urea treatment of rice straw improved feed intake, digestibility, rumen fermentation and efficiency of microbial N synthesis in crossbred dairy steers.

• 식품과학과 산업
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• 제50권3호
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• pp.93-104
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• 2017

monosodium L-glutamate (MSG), composed of 88% L-glutamic acid (GLU) and 12% Na, is considered as Generally Recognized as Safe. GLU is accounting for 15% of the total amino acid content in our body. Daily GLU intake is large 3.5-10.6 g from food and 1.3 g from food additive. The daily formed GLU in the body, via degradation of the total protein, is 48-50 g (70 kg of male) and the maintained GLU in the body is total bound GLU (1.4-2.0 kg) and free GLU (10 g). About 88% GLU are consumed at digestive tract, and only 12% GLU enter the blood stream. GLU is generally known to precursors of N-acetyl glutamate and glutamine, substrates for protein synthesis, a neurotransmitter (GABA), and the active site of the enzyme. In addition to protein synthesis, GLU has these key functions within the body, thus this amino acid is critical for healthy body maintenance and function.

• Asian-Australasian Journal of Animal Sciences
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• 제29권8호
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• pp.1111-1119
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• 2016

Mao seed is a by-product of the wine and juice industry, which could be used in animal nutrition. The current study was designed to determine the effect of supplementation of mao (Antidesma thwaitesianum Muell. Arg.) seed meal (MOSM) containing condensed tannins (CT) on rumen fermentation, nitrogen (N) utilization and microbial protein synthesis in goats. Four crossbred (Thai Native${\times}$Anglo Nubian) goats with initial body weight (BW) $20{\pm}2kg$ were randomly assigned to a $4{\times}4$ Latin square design. The four dietary treatments were MOSM supplementation at 0%, 0.8%, 1.6%, and 2.4% of total dry matter (DM) intake, respectively. During the experimental periods, all goats were fed a diet containing roughage to concentrate ratio of 60:40 at 3.0% BW/d and pangola grass hay was used as a roughage source. Results showed that supplementation with MOSM did not affect feed intake, nutrient intakes and apparent nutrient digestibility (p>0.05). In addition, ruminal pH and ammonia nitrogen ($NH_3$-N) were not influenced by MOSM supplementation, whilst blood urea nitrogen was decreased quadraticly (p<0.05) in goats supplemented with MOSM at 2.4% of total DM intake. Propionate was increased linearly with MOSM supplementation, whereas acetate and butyrate were remained the same. Moreover, estimated ruminal methane ($CH_4$) was decreased linearly (p<0.05) when goats were fed with MOSM at 1.6% and 2.4% of total DM intake. Numbers of bacteria and protozoa were similar among treatments (p>0.05). There were linear decreases in urinary N (p<0.01) and total N excretion (p<0.01) by MOSM supplementation. Furthermore, N retention was increased linearly (p<0.05) when goats were fed with MOSM supplementation at 1.6% and 2.4% of total DM intake. Microbial protein synthesis were not significantly different among treatments (p>0.05). From the current study, it can be concluded that supplementation of MOSM at 1.6% to 2.4% of total DM intake can be used to modify ruminal fermentation, especially propionate and N utilization in goats, without affecting the nutrient digestibility, microbial populations and microbial protein synthesis.