• Korean Journal of Veterinary Research
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• v.29 no.4
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• pp.425-431
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• 1989

This study was undertaken to investigate the changes of enzyme activities resulted from low concentrated carbon monoxide poisoning on the caudate nucleus in rat. The activities of cytochrome oxidase, succinate dehydrogenase and lactate dehydragenase were observed histochemically, after the experimental animals were poisoned to 100ppm carbon monoxide for 8 hours every day from one day to 16 days. The materials were sliced from coronal section at the level of the optic chiasm and immediately frozen sections of $10{\mu}m$ thickness were cut on the cryostat at $-15^{\circ}C$ and incubated in the medium containing substrate for histochemical detection of cytochrome oxidase, succinate dehydrogenase and lactate dehydrogenase. The sections were mounted in glycerol gelatin and observed under light microscope. It was obtained that cytochrome oxidase activity decreased moderately and succinate dehydrogenase activity showed marked or moderate activity during entire poisoning period and lactate dehydrogenase activity showed marked or moderate activity from one to 8 days but recovered to normal condition at 16th day.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.365-367
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• 1999

A fuel cell type biosensor for lactate was developed using a metal-reducing bacterium, Shewanella putrefaciens IR-1. Under the operational conditions, the bacterial cell suspension generated the current without an electrochemical mediator in the presence of lactate. The current was proportional to the lactate concentration up to 30 mM.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.3
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• pp.435-441
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• 2015

Relationships among different stress parameters (lairage time and blood level of lactate and cortisol), meat quality parameters (initial and ultimate pH value, temperature, drip loss, sensory and instrumental colour, marbling) and carcass quality parameters (degree of rigor mortis and skin damages, hot carcass weight, carcass fat thickness, meatiness) were determined in pigs (n = 100) using Pearson correlations. After longer lairage, blood lactate (p<0.05) and degree of injuries (p<0.001) increased, meat became darker (p<0.001), while drip loss decreased (p<0.05). Higher lactate was associated with lower initial pH value (p<0.01), higher temperature (p<0.001) and skin blemishes score (p<0.05) and more developed rigor mortis (p<0.05), suggesting that lactate could be a predictor of both meat quality and the level of preslaughter stress. Cortisol affected carcass quality, so higher levels of cortisol were associated with increased hot carcass weight, carcass fat thickness on the back and at the sacrum and marbling, but also with decreased meatiness. The most important meat quality parameters (pH and temperature after 60 minutes) deteriorated when blood lactate concentration was above 12 mmol/L.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.2
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• pp.45-55
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• 2007

We elucidated the effects of various components of ischemic medium on the outcome of simulated ischemia-reperfusion injury. Hypoxia for up to 12 hours induced neither apoptotic bodies nor LDH release. However, reoxygenation after 6 or 12 hours of hypoxia resulted in a marked LDH release along with morphological changes compatible with oncotic cell death. H9c2 cells were then subjected to 6 hours of simulated ischemia by exposing them to modified hypoxic glucose-free Krebs-Henseleit buffer. Lowered pH (pH 6.4) of simulated-ischemic buffer resulted in the generation of apoptotic bodies during ischemia, with no concomitant LDH release. The degree of reperfusion-induced LDH release was not affected by the pH of ischemic buffer. Removal of sodium bicarbonate from the simulated ischemic buffer markedly increased cellular damages during both the simulated ischemia and reperfusion. Addition of lactate to the simulated ischemic buffer increased apoptotic cell death during the simulated ischemia. Most importantly, concomitant acidosis and high lactate concentration in ischemic buffer augmented the reperfusion-induced oncotic cell death. These results confirmed the influences of acidosis, bicarbonate deprivation and lactate on the progression and outcome of the simulated ischemia-reperfusion, and also demonstrated that concomitant acidosis and high lactate concentration in simulated ischemic buffer contribute to the development of reperfusion injury.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.214-221
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• 2011

Effects of the cell wall-degrading enzymes derived from Acremonium cellulolyticus and Trichoderma viride on the silage fermentation and in sacco degradation of tropical grasses i.e. rhodesgrass (Chloris gayana Kunth. cv. Callide) and guineagrass (Panicum maximum Jacq. cv. Natsukaze) were investigated in laboratory-scale experiments. These two grasses were either treated with or without the enzymes before ensiling. Untreated rhodesgrass produced acetate fermentation silage (lactate, $13.0\;g\;kg^{-1}$ DM; acetate, $38.7\;g\;kg^{-1}$ DM) with high final pH value and $NH_3$-N content (5.84 and $215\;g\;kg^{-1}$ DM). Addition of enzymes significantly increased (p<0.01) the lactate production (lactate, 45.6; acetate, $34.0\;g\;kg-^{1}$ DM) and decreased (p<0.01) the pH and $NH_3$-N (4.80 and $154\;g\;kg^{-1}$ DM) in the ensiled forages when compared with the control silages. Untreated guineagrass was successfully preserved with a high lactate proportion (lactate, 45.5; acetate, $24.1\;g\;kg^{-1}$ DM), and the addition of enzymes further enhanced the desirable fermentation (lactate, $57.5\;g\;kg^{-1}$ DM; acetate, $19.4\;g\;kg^{-1}$ DM). The content of NDF was lowered (p<0.05) by enzymes in both silages, but the extent appeared greater in the enzyme-treated rhodesgrass (rhodesgrass, $48\;g\;kg^{-1}$ DM; guineagrass, $21\;g\;kg^{-1}$ DM). Changes in the kinetics of in sacco degradation showed that enzyme treatment increased (p<0.01) the rapidly degradable DM (rhodesgrass, 299 vs. $362\;g\;kg^{-1}$ DM; guineagrass, 324 vs. $343\;g\;kg^{-1}$ DM) but did not influence the potential degradation, lag time and degradation rate of DM and NDF in the two silages.

• Journal of Korean Physical Therapy Science
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• v.10 no.1
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• pp.149-157
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• 2003

The purpose of this study was to compare the effects of different exercise types including isokinetic, isometric, and istonic exercise of same exercise intensity on cardiopulmonary function and blood lactate level. The subjects of this study included 17 males college students. Each subjects after pretraining measurement performed isokinetic, isometric and isotonic exercise of 1 week interval using Cybex 6000 System. KBI-C and YSI 1500 were used to measure changes in cardiopulmonary function and blood lactate level respectively. First, comparing changes in RPP relative to exercise type, isokinetic group showed significant difference between before exercise ($7.08{\pm}1.12mg/kg/min$) and post exercise ($18.98{\pm}1.75mg/kg/min$). Isometric group showed that significant difference between before exercise($7.89{\pm}0.98mg/kg/min$) and post exercise($20.22{\pm}2.41mg/kg/min$). Isotonic group showed significant difference between before exercise ($8.14{\pm}0.11mg/kg/min$) and post exercise ($19.84{\pm}2.30\;mg/kg/min$). Second, comparing changes in blood lactate level relative to exercise type, isokineic group showed significant difference between before exercise ($2.99{\pm}0.65mmol$) and post exercise ($6.55{\pm}6.55mmol$). Isometric group showed significant difference between before exercise($1.71{\pm}5.48mmol$) and post exercise ($5.48{\pm}1.97mmol$). Isotonic group showed significant difference between before exercise($1.16{\pm}0.48mmol$) and post exercise($5.21{\pm}1.28mmol$). The results of this study indicate significant differences RPP in isometric exercise and significant differences blood lactate in isotonic exercise.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.95-102
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• 2005

Effects of Morus alba fruit extracts on monoamine oxidase (MAO) activity were examined in rats during and after physical exercise. Oral administration of M. alba extract (0.3 g/kg body weight) significantly increased brain MAO-A activity but decreased liver MAO-B activity when they were measured using serotonin and benzylamine as substrates. Type of physical exercises had significant effect on MAO activity. Brain MAO-A activity markedly decreased with physical activity-related stress compared to normal group, whereas Liver MAO-B activity increased up to 60 min after exercise. Lactate dehydrogenase (LDH) activity and lactate concentration in blood, clinical indices of physical exercise activities, were also determined for correlation to MAO activities. MAO-A activity of rats subjected to oral administration of M. alba extract and physical exercise increased whereas MAO-B and LDH activities, and lactate level decreased, All indices eventually recovered normal levels, These results suggest M. alba may increase capability of physical activities by modulating MAO activities during exercise.

• Investigative Magnetic Resonance Imaging
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• v.19 no.4
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• pp.212-217
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• 2015

Purpose: For a single time-point hyperpolarized $^{13}C$ magnetic resonance spectroscopy imaging (MRSI) of animal models, scan-time window after injecting substrates is critical in terms of signal-to-noise ratio (SNR) of downstream metabolites. Pre-scans of time-resolved magnetic resonance spectroscopy (MRS) can be performed to determine the scan-time window. In this study, based on two-site exchange model, protocol-specific simulation approaches were developed for $^{13}C$ MRSI and the optimal scan-time window was determined to maximize the SNR of downstream metabolites. Materials and Methods: The arterial input function and conversion rate constant from injected substrates (pyruvate) to downstream metabolite (lactate) were precalibrated, based on pre-scans of time-resolved MRS. MRSI was simulated using two-site exchange model with considerations of scan parameters of MRSI. Optimal scan-time window for mapping lactate was chosen from simulated lactate intensity maps. The performance was validated by multiple in vivo experiments of BALB/C nude mice with MDA-MB-231 breast tumor cells. As a comparison, MRSI were performed with other scan-time windows simply chosen from the lactate signal intensities of pre-scan time-resolved MRS. Results: The optimal scan timing for our animal models was determined by simulation, and was found to be 15 s after injection of the pyruvate. Compared to the simple approach, we observed that the lactate peak signal to noise ratio (PSNR) was increased by 230%. Conclusion: Optimal scan timing to measure downstream metabolites using hyperpolarized $^{13}C$ MRSI can be determined by the proposed protocol-specific simulation approaches.

• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.319-327
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• 2000

This study was conducted to prolong the edible period of Kimchi by adding chitosan (0.25, 0.5%) and sodium salts of various organic acids(0.01~0.04M citrate, malate, lactate) . The edible period was estimated by measuring changes in pH. titratable acidity(TA), PH/TA ratio, ascorbic acid content and pectin fraction during Kimchi fermentation at 2$0^{\circ}C$. The results were compared by estimating the maturity of Kimchi fermentation. Kimchi with the chitosan showed higher pH and titratable acidity throughout the fermentation period than that without chitosan. The pH decreased during the fermentation in the order of control, 0.25% chitosan, 0.5% chitosan, 0.5% chitosan+Na-citrate, 0.5% chitosan+Na-malate and 0.5% chitosan+Na-lactate. But the titratable acidity increased in the order of control, 0.5% chitosan+Na-malate, 0.25% chitosan. 0.5% chitosan+Na-citrate, 0.5% chitosan and 0.5% chitosan+Na-lactate. The PH/TA ratio decreased in the order of control, 0.25% chitosan, 0.5% chitosan+Na-malate, 0.5% chitosan, 0.5% chitosan+Na-citrate and 0.5% chitosan+Na-lactate. Ascorbic acid content in Kimchi was the highest at the 3rd day and then decreased during fermentation. Ascorbic acid content in Kimchi containing 0.5% chitosan and organic acid salts was higher than others. Alcohol insoluble solids( AIS ) in Kimchi decreased during fermentation in the order of control, 0.25% chitosan, 0.5% chitosan, 0.5% chitosan+Na-palate. 7.5% chitosan+Na-lactate and 0.5% chitosan+Na-citrate. During fermentation, hot water soluble pectin (HWSP) of control increased, whereas HCI soluble pectin (HCISP) decreased. By addition of chitosan, however, the results became reverse. Chitosan addition appeared to be effective in improving preservation quality of Kimchi during fermention. The edible period become extended by using chitosan plus organic acids instead of using chitosan only. Overall. addition of 0.5% chitosan+Na-lactate seemed most effective in prolonging the edible periods during Kimchi fermentation.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.369-374
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• 2015

This study was conducted to compare the glucose, lactate, and nucleotide degradation products content of cooked beef steaks from Korean Hanwoo (quality grade: 1) and Australian cattle (Bos indicus, grain-fed for 100 d) by internal temperature. The loins (M. longissimus dorsi) and top rounds (M. semimembranosus) from two cattle breeds were cut into about 2 cm thickness and then cooked in a $180^{\circ}C$ electronic oven until internal temperature attained to 50, 70, or $90^{\circ}C$. Regardless of internal temperature, glucose content was higher (P<0.05) in cooked loin and top round steaks from Hanwoo compared to those from Australian cattle. Lactate content was shown to be lower (P<0.05) in cooked steaks from Hanwoo than in those from Australian cattle. Lower (P<0.05) hypoxanthine and higher (P<0.05) guanosine 5'-monophosphate, inosine 5'-monophosphate, inosine contents were observed in cooked steaks from Hanwoo. Furthermore, glucose content tended to be decreased by internal temperature but nucleotide degradation products content was not changed by internal temperature. Therefore, these findings suggest that cooked Hanwoo beef steaks had higher flavor precursors related to sweet and umami tastes than cooked Australian beef steaks