• Journal of Microbiology and Biotechnology
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• 제9권3호
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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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• 제28권3호
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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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• 제11권2호
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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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• 제24권2호
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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.

• 대한물리치료과학회지
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• 제10권1호
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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.

• 한국식품과학회지
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• 제37권1호
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• pp.95-102
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• 2005

상심자 추출물이 운동에 의한 체내 monoamine oxidase (MAO) 활성 변화에 미치는 영향을 연구하여. 상심자 추출물을 경구투여(0.3g/kg body weight) 한 흰쥐의 뇌와 간에서 MAO-A와 MAO-B의 활성에 중요한 영향을 미치는 사실을 확인하였다. 각 효소활성은 serotonin과 benzylamine을 기질로 이용하여 측정하였다. 운동 전 후 운동의 유형에 따라 효소활성의 변화경향이 서로 다른 경향을 나타내었다. 뇌에서 측정한 MAO-A 활성은 운동에 의해 효소활성이 현저히 감소하였으며 반면, 간에서 측정한 MAO-B의 활성은 운동이 끝나고 60분이 경과할 때까지 증가된 상태를 유지하고 있었다. 운동 시 체내 변화의 지표효소인 혈중 LDH의 활성 변화와 혈중 lactate의 농도변화를 함께 관찰함으로서 MAO 활성과의 상관관계를 비교하였다. 상심자 추출물을 경구투여 하고 운동을 한 동물의 MAO-A 활성은 증가하였고 MAO-B, LDH 활성과 lactate level은 감소하는 것을 확인하였다. 결과적으로 모은 지표들이 운동 전의 정상상태로 회복되는 것으로 확인되었다. 이 연구의 결과들로부터 상심자 추출물이 운동 전후의 MAO 활성을 조절함으로써 운동능력을 향상시키고 피로를 회복하는 효능을 갖는 것으로 추정되며 이러한 기능성을 갖는 건강기능식품의 소재로 활용이 가능할 것으로 생각한다.

• Investigative Magnetic Resonance Imaging
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• 제19권4호
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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.

• 한국식품영양학회지
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• 제13권4호
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• pp.319-327
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• 2000

배추김치에 0.25% chitosan, 0.5% chitosan, 0.5% chitosan+0.04M Na-malate, 0.5% chitosan+0.04M Na-lactate, 0.5% chitosan+04M Na-citrate를 첨가하여 김치의 숙성 과정 중 pH, 산도, pH/TA ratio, ascorbic acid 함량 및 Pectin질의 변화에 대한 영향을 알아보았다. 그 결과는 다음과 같다. 1. 김치의 숙성과정 중 pH는 감소하는 경향을 보였으며, 대조군, 0.25% chitosan 첨가군, 0.5% chitosan 첨가군, 0.5% chitosan+Na-citrate 첨가군, 0.5% chitosan+Na-malate 첨가군, 0.5% chitosan+Na-lactate 첨가군의 순으로 감소하였다. 2. 김치의 숙성과정 중 산도는 증가하는 경향을 보였으며, 대조군, 0.5% chitosan+Na-malate 첨가군, 0.25% chitosan 첨가군, 0.5% chitosan+ Na-citrate 첨가군. 0.5% chitosan 첨가군, 0.5% chitosan+Na-lactate 첨가군의 순으로 증가하였다. pH/TA ratio는 김치의 숙성 중 감소하는 경향을 보였으며. 대조군, 0.25% chitosan 첨가군, 0.5% chitosan+Na-malate 첨가군, 0.5% chito-san+Na-citrate 첨가군, 0.5% chitosan+Na-lactate 첨가군의 순으로 감소하였다. 3. Ascorbic acid 함량은 3일째에 가장 높은 함량을 보였으며, 0.5% chitosan에 유기산염 병용첨가군이 다른 군들보다 월등히 높았다. 그 후 숙성기간이 경과할수록 감소하였다. 4. AIS 함량의 변화는 숙성기간이 지날수록 모두 감소하는 경향을 보였으며, 대조군, 0.25% chit-osan 첨가군, 0.5% chitosan 첨가군, 0.5% chito-san+Na-citrate 첨가군, 0.5% chitosan+Na-lactate 첨가군, 0.5% chitosan+Na-citrate 첨가군 순으로 감소하였다. 5. AIS로부터 펙틴을 추출하여 HWSP, HXSP, HCISP로 분획한 함량비는 대조군이 숙성이 진행됨에 따라 HWSP가 증가하고 HCISP는 감소하는 경향을 보인 반면, chitosan 첨가군은 숙성이 진행됨에 따라 HWSP가 감소하고 HCISP는 증가하는 경향을 나타내었다. 위와 같은 결과로부터 chitosan의 첨가는 김치의 보존성 향상에 효과를 보였으며. 유기산염과 병용첨가군이 단독첨가군보다 더욱 효과적이었다. 유기산염의 종류에 따른 병용에 있어서는 Na-lactate 첨가군이 Na-citrate와 Na-malate 첨가군보다 효과적으로 나타났다.

• 농업과학연구
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• 제42권4호
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• pp.369-374
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• 2015

본 연구는 가열 한우육 및 호주산우육 스테이크에서 심부온도에 따른 glucose, lactate 및 핵산 분해 물질 함량을 비교하고자 실시하였다. 시료로 한우육(거세우, 1등급) 및 호주산우육(Bos indicus, 100일 곡류 비육)의 등심(M. longissimus dorsi)과 우둔(M. semimembranosus)를 약 2 cm 두께로 절단하여 각각 세 그룹으로 나누고, $180^{\circ}C$ 오븐에서 심부온도가 각각 50, 70 및 $90^{\circ}C$가 되도록 가열하였다. Glucose 함량은 심부온도에 관계없이 한우육 스테이크가 호주산우육 스테이크에 비해 현저하게 높았다(P<0.05). 이와 반대로 lactate 함량은 한우육 스테이크가 호주산우육 스테이크보다 낮았다(P<0.05). 핵산 분해 물질 중 Hx 함량은 모든 심부온도에서 한우육 스테이크가 호주산우육 스테이크보다 낮았던 반면(P<0.05), GMP, IMP 및 inosine 함량은 한우육 스테이크가 높았다(P<0.05). 심부온도가 증가함에 따라 쇠고기 스테이크의 glucose 함량은 감소하는 경향을 보였으나, lactate 함량은 일정한 경향을 보이지 않았다. 또한 핵산 분해 물질 함량은 심부온도의 증가에 따라 유의적인 변화를 보이지 않았다. 따라서 가열 한우육 스테이크의 단맛 및 감칠맛 관련 풍미 전구물질 함량이 호주산우육 스테이크보다 높았다.

• Asian-Australasian Journal of Animal Sciences
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• 제11권6호
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• pp.655-660
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• 1998

To produce blastocysts more efficiently, it is required to identity accurately the factors involving embryonic cleavage in the chemically defined medium. Effects of pyruvate, lactate, calcium and protein sources on early cleavage of bovine follicular oocytes were investigated. The percentage of IVF embryos cleaved to ${\geq}$ 2-cell or ${\geq}$ 8-cell was higher in pyruvate (+) and lactate (+) (48 or 14%) than in pyruvate (-) and lactate (-) (22% or 4%), than in pyruvate (+) and lactate (-) (28% or 5%) and than in pyruvate (-) and lactate (+) (40% or 10%). Lactate was more effective than pyruvate during early cleavage of bovine embryos in the chemically defined medium. The percentage of IVF embryo cleaved to ${\geq}$ 2-cell and ${\geq}$ 8-cell in calcium (-) (19 and 6%) was significantly (p < 0.05) lower than in calcium (+) (78 and 45%). The percentage of embryos developed to ${\geq}$ 2-cell showed no significant (p < 0.05) difference among BSA, 1 and 20% FBS (57, 57 and 57%). Also the percentage of A grade embryos developed to ${\geq}$ 2-cell showed no significant (p < 0.05) difference among BSA, 1 and 20% FBS (40, 35 and 28%). The percentage of embryos developed to ${\geq}$ 8-cell showed no significant (p < 0.05) difference among BSA, 1 and 20% FBS (33, 23, and 22%). However, the percentage of A grade embryos developed to ${\geq}$ 8-cell in BSA (24%) was significantly (p < 0.05) higher than in 1 and 20% FBS (13 and 8%). The percentage of embryos developed to ${\geq}$ morula showed no significant (p < 0.05) difference among BSA, 1, 10 and 20% FBS (76, 76, 80 and 68%). The percentage of A grade embryos developed to ${\geq}$ morula in 10% FBS (59%) was significantly (p < 0.05) higher than 20% FBS (43%). The percentage of embryos developed to blastocyst showed no significant (p < 0.05) difference among BSA, 1, 10 and 20% FBS (34, 41, 43 and 32%). However, the percentage of A grade embryos developed to ${\geq}$ blastocysts in 10% FBS (25%) was significantly (p < 0.05) higher than in 20% FBS (8%).