• Asian-Australasian Journal of Animal Sciences
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• 제19권6호
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• pp.898-904
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• 2006

Effects of sodium bicarbonate (SBC) injection on meat quality and functionality of porcine M. longissimus lumborum were investigated. Fifteen pigs ($100{\pm}5kg$) were randomly selected at a commercial slaughter plant. After slaughtering the loins were dissected from the carcass before chilling at approximately 30 minutes post mortem. The loins were divided into four cuts for sample treatment, and SBC of 0.25 M, 0.40 M and 0.75 M was injected (2% w/w) using a syringe. As SBC injection level was increased, muscle pH increased significantly (p<0.05). SBC injection decreased lightness ($L^*$) values on the surface of muscle. Moreover, with injection of SBC, drip loss %, cooking loss % and shear force were significantly (p<0.05) decreased, whereas WHC and $Na^+$ content were significantly (p<0.05) increased. From panel testing of uncooked pork loin, no significant differences (p>0.05) were found in aroma, off-flavor and drip between injection of SBC at different levels and the control, although color and acceptability were significantly lower (p<0.05) in control pork loin compare with injection of SBC at 0.75 M. In cooked pork loin from the panel test, aroma, flavour, off-flavour and juiciness were found to be similar (p>0.05) on all treatments, but tenderness and acceptability were significantly higher (p<0.05) with injection of SBC at 0.75 M than for control loin. Myofibrillar protein solubility of muscles treated with SBC was significantly (p<0.05) higher than that of the control, although no significant differences (p>0.05) were found in sarcoplasmic protein solubility between the treatments. These results indicated that SBC injection into pre-rigor porcine M. longissimus lumborum could improve ultimate pork quality characteristics such as meat color, water-holding capacity, and could inhibit muscle protein denaturation due to an increase in muscle pH.

• Biomaterials and Biomechanics in Bioengineering
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• 제2권4호
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• pp.225-235
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• 2015

Treatments for asthma are largely pharmaceutical, with some therapies also utilising alternative breathing techniques. The objective of both medical and alternative methods is to relax contracted airway smooth muscle (ASM). In normal subjects, tidal breathing- and deep inspiration-oscillations are believed to have a bronchodilatory effect. Similarly, application of length oscillations to isolated, contracted ASM also elicits muscle relaxation. As a means of investigating more-effective alternative treatment methods for contracted airways, we analyse the combined effects of bronchodilators and length oscillations on isolated, contracted ASM. The contractile state of the muscle tissue prior to treatment is of primary interest. Thereafter, the effect of applying a combination of small superimposed length oscillations with tidal breathing-like oscillations to ASM is studied alone and in combination with a common bronchodilator, isoproterenol (ISO). This work suggests that relaxation of isolated, contracted ASM following application of combined oscillations and ISO is larger than treatments of either combined oscillations or ISO alone. Further, the observed oscillation-associated relaxation is found to be amplitude- rather than frequency-dependent. This study gives additional insight into the role of oscillations and bronchodilators on contracted airways.

• Asian-Australasian Journal of Animal Sciences
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• 제20권10호
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• pp.1612-1617
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• 2007

In this study, we have compared the skeletal muscle proteome at various stages of porcine postnatal development. Korean native pigs were divided into five postnatal stages of 30, 70, 130, 170 and 300 d and their loin muscles were analyzed for muscle proteome by using two-dimensional electrophoresis and mass spectrometry. We found 5 proteins showing a consistent pattern during skeletal muscle growth. Four proteins were identified as myosin light chain 1 slow-twitch (MLC1sa) isoform, troponin T, triosephosphate isomerase (TIP) and DJ-1 protein. The remaining protein was not identified. Two muscle fiber proteins of MLC1sa isoform and troponin T showed a high expression level at an early postnatal stage and then their levels were decreased markedly during growth stages. On the other hand, the expression of TIP and DJ-1 protein, which are well known as catalysis enzyme and antioxidant-related protein, respectively, were linearly increased during growth stages. Thus, the stage-related muscle proteins may be useful as parameters for understanding the developmental characteristics of biochemical and physiological properties in Korean native pig skeletal muscle.

• 대한수의학회지
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• 제37권1호
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• pp.119-128
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• 1997

The relaxation of gastric fundus smooth muscles is the primary physiological event which induces the receptive relaxation of monogastric animals. L-arginine/Nitric oxide(L-arg/NO) system is known to mediate the inhibitory non-adrenergic non-cholinergic(NANC) neurotransmission in various tissues including gastrointestinal smooth muscles. The longitudinal smooth muscles of porcine gastric fundus showed fast relaxation during electrical field stimulation(EFS) and rebound contraction after EFS in NANC condition. So, the purpose of present study was elucidation of the neurotrasmitters related to the NANC relaxation and explanation of the relation between NANC relaxation and L-arg/NO system. The longitdinal smooth muscles of porcine gastric fundus were hung in the organ bath and under the presence of guanethidine($5{\times}10^{-5}M$), precontraction was induced by carbachol($1{\times}10^{-6}M$). The muscle responses to EFS and drugs were isomerically recorded. The rusults were summarized as follows. 1. The longtudinal muscles of porcine gastric fundus showed frequency-dependent relaxation and rebound contraction to electrical field stimulaton(1ms, 8V, 1~16Hz, 20sec, EFS). These responses were blocked by tetrodotoxin($1{\times}10^{-6}M$). 2. The relaxation and rebound contraction of the longitudinal muscles of porcine gastric fundus to EFS were inhibited by L-NAME($2{\times}10^{-5}M$). The inhibitory effect of L-NAME was antagonized by L-arginine($1{\times}10^{-3}M$), but not by D-arginine($1{\times}10^{-3}M$). 3. Exogenous NO($NaNO_2$, $1{\times}10^{-5}{\sim}1{\times}10^{-4}M$, pH=2.0) caused concentration-dependent relaxation as EFS did. 4. Methylene Blue($2{\times}10^{-5}M$), a soluble guanylate cyclase inhibitor, inhibited the relaxation and rebound contraction of the longitudinal muscles of porcine gastric fundus induced by EFS, but N-ethlmaleimide, a adenylate cyclase inhibitor, did not. 5. 8-Br-cGMP($1{\times}10^{-6}{\sim}3{\times}10^{-6}M$), permeable cGMP analogue, induced dose-dependent relaxation. but 8-Br-cAMP($1{\times}10^{-6}{\sim}3{\times}10^{-6}M$), permeable cAMP analogue, did not. Both did not evoked rebound contraction. 6. ${\alpha}$-chymotrypsin did not affect the relaxation of the longitudinal muscles of porcine gastric fundus. 7. Reactive blue 2($1{\times}10^{-4}M$, 40min) siginificantly inhibited the rebound contraction induced by EFS and inhibited contraction caused by exogenous ATP($1{\times}10^{-4}{\sim}1{\times}10^{-3}M$). These results suggests that NANC relaxation of the longitudinal muscles of porcine gastric fundus mainly mediated by NO and the rebound contraction is related to NO and other neurotransmitters.

• Asian-Australasian Journal of Animal Sciences
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• 제20권8호
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• pp.1297-1304
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• 2007

We conducted a series of investigations in order to elucidate role of nutritional status in regulating GLUT expression and energy metabolism in porcine muscle. Firstly, the role of mild undernutrition in regulating muscle GLUT gene expression and function was studied in growing pigs (3 wk of age) on a high (H) or low (L) food intake (H = 2L) at $35^{\circ}C$ or $26^{\circ}C$. Low food intake selectively upregulates GLUT1 and GLUT4 gene expression; mRNA levels were elevated in longissimus dorsi (L. dorsi) and rhomboideus muscles but not in diaphragm or cardiac muscles. Our next step was to determine whether dietary lysine, a major primary limiting amino acid in diets for pigs, affects muscle GLUT4 expression. Pigs of 6 wk of age were pair-fed a control or low lysine (LL) diet. The control diet contained optimal amounts of all essential amino acids, including 1.15% lysine. The LL diet was similar but contained only 0.70% lysine. GLUT4 mRNA expression was upregulated by the LL diet in L. dorsi and rhomboideus muscles, whereas that in cardiac muscle was unaffected. GLUT4 protein abundance was also higher in rhomboideus muscle of animals on the LL diet. We conducted another investigation in order to elucidate effects of the LL diet on post-GLUT4 glucose metabolism. Activity of hexokinase was unaffected by dietary lysine levels while that of citrate synthase was higher both in L. dorsi and rhomboideus muscles of pigs fed on the LL diet. Glucose 6-phosphate content was higher in L. dorsi msucle in the LL group. Glycogen content was higher both in L. dorsi and rhomboideus muscles in the LL group. Further, we determined the effects of dietary lysine levels on accumulation of intramuscular fat (IMF) in L. dorsi muscle of finishing pigs. A low lysine diet (lysine content was 0.40%) meeting approximately 70% of the requirement of lysine was given to finishing pigs for two months. IMF contents in L. dorsi of the pigs given the low lysine diet were twice higher than those of the pigs fed on a control diet (lysine content was 0.65%). Finally, we proved that a well known effect of breadcrumbs feeding to enhance IMF of finishing pigs could be attributed to shortage of amino acids in diets including breadcrumbs.

• 한국축산식품학회지
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• 제38권4호
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• pp.711-717
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• 2018

Myogenic factor 5 (MYF5) plays an important role in regulating skeletal muscle fiber characteristics, consequently affecting meat production and quality. We identified a novel p.A41P mutation in exon1 of the porcine MYF5 gene by direct sequencing. The mutation was predicted to be destabilizing in protein structure based on the resultant amino acid substitution. We estimated the significant substitution effect of p.A41P on the energy stabilization of Myf5 protein structure. Then, we demonstrated that the mutation in Yorkshire population significantly affected muscle fiber type I composition (p<0.05), loin-eye area of lean meat content (p<0.05) and filter-fluid uptake of meat quality (p<0.01). Furthermore, dominant effects significantly influenced total muscle fiber number (p<0.05). This study suggests that the novel p.A41P mutation in porcine MYF5 may be a valuable genetic marker to affect the muscle fiber characteristics and consequently improve meat production quality and quantity.

• Journal of Animal Science and Technology
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• 제45권5호
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• pp.731-738
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• 2003

근육의 생화학적 특성을 단백질 수준에서 분석하기 위하여 3원교잡종 돼지 3개체를 선발하고, white muscle은 longissimus dorsi muscle을 red muscle은 soleus muslce을 분리하여 분석에 이용하였다. 각 근육조직은 수용성, 불수용성 단백질 및 총단백질로 분리하여 추출하였고, 이차원전기영동 분석을 위하여 17cm 길이의 immobilized pH gradient strip (Bio-Rad, 3-10NL)과 12% acrylamide gel을 이용하여 전개하였다. 각각의 gel은 coomassie stain과 silver stain을 통하여 가시화 하였고, PDQuest software을 통하여 단백질 발현양상을 분석하였다. 하나의 gel에서 평균 600개 이상의 단백질 spot을 관찰하였으며, 반복실험을 통하여 white muscle과 red muscle간에 발현의 차이를 보이는 5개의 단백질 spot을 확인할 수 있었다. 5개의 spot 중 4개의 단백질은 측정된 분자량과 pI값이 troponin I, T 및 myoglobin의 수치값과 유사한 것으로 확인되었다. 그러나, 1개의 spot은 오차범위 내에서 유사한 단백질을 확인할 수 없었다. 5개의 단백질 spot중 1개(spot 1)는 white muscle에서, 4개의 spot(spot 2～5)은 red muscle에서 높게 발현됨을 확인하였으며, 특히 spot 4의 경우 white muscle 보다 red muscle에서 평균 14.6배 높게 발현됨을 확인하였다. 본 연구는 근육의 생화학적 특성을 이해하는데 중요한 기초 자료로 활용될 수 있으며, 앞으로 white muscle과 red muscle의 단백질 발현 분석을 통하여 단백질 수준에서의 생화학적 특성에 관한 연구가 충분히 진행되어야 할 것이다.

• 한국식품과학회지
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• 제21권4호
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• pp.505-510
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• 1989

1. 섬유간 지방질 함량은 소와 닭의 근섬유의 경우에는 white muscle보다 red muscle에서 높게 나타났으나 돼지 근섬유의 경우에는 white muscle쪽이 높았다. 2. 근섬유간 지질의 분포를 살펴보면 중성지질이 가장 많이 차지하고 극성지질과의 조성비에 있어서는 동물의 종 및 muscle type에 따라 다르게 나타났다. 3. 지방관의 조성에 있어서는 불포화 지방산의 함량비가 두 muscle type 사이에서 다르게 나타났으며 특히 돼지의 근섬유간 지방질에는 고도불포화지방산 함량이 높은 특징을 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제31권1호
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• pp.3-12
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• 2018

Objective: DNA methylation plays a major role in regulating the expression of genes related to traits of economic interest (e.g., weight gain) in livestock animals. This study characterized and investigated the functional inferences of genome-wide DNA methylome in the loin (longissimus dorsi) muscle (LDM) of swine. Methods: A total of 8.99 Gb methylated DNA immunoprecipitation sequence data were obtained from LDM samples of eight Duroc pigs (four pairs of littermates). The reference pig genome was annotated with 78.5% of the raw reads. A total of 33,506 putative methylated regions (PMR) were identified from methylated regions that overlapped at least two samples. Results: Of these, only 3.1% were commonly observed in all eight samples. DNA methylation patterns between two littermates were as diverse as between unrelated individuals (p = 0.47), indicating that maternal genetic effects have little influence on the variation in DNA methylation of porcine LDM. The highest density of PMR was observed on chromosome 10. A major proportion (47.7%) of PMR was present in the repeat regions, followed by introns (21.5%). The highest conservation of PMR was found in CpG islands (12.1%). These results show an important role for DNA methylation in species- and tissue-specific regulation of gene expression. PMR were also significantly related to muscular cell development, cell-cell communication, cellular integrity and transport, and nutrient metabolism. Conclusion: This study indicated the biased distribution and functional role of DNA methylation in gene expression of porcine LDM. DNA methylation was related to cell development, cell-cell communication, cellular integrity and transport, and nutrient metabolism (e.g., insulin signaling pathways). Nutritional and environmental management may have a significant impact on the variation in DNA methylation of porcine LDM.

• Asian-Australasian Journal of Animal Sciences
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• 제20권5호
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• pp.768-774
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• 2007

To study the effect of dietary docosahexaenoic acid (DHA) enrichment on the expression of hepatic genes in pigs, weaned, crossbred pigs (30 d old) were fed diets supplemented with either 2% tallow or DHA oil for 18 d. Hepatic mRNA was extracted. Suppression subtractive hybridization was used to explore the hepatic genes that were specifically regulated by dietary DHA enrichment. After subtraction, we observed 288 cDNA fragments differentially expressed in livers from pigs fed either 2% DHA oil or 2% tallow for 18 d. After differential screening, 7 genes were found to be differentially expressed. Serum amyloid A protein 2 (SAA2) was further investigated because of its role in lipid metabolism. Northern analysis indicated that hepatic SAA2 was upregulated by dietary DHA enrichment (p<0.05). In a second experiment, feeding 10% DHA oil for 2d significantly increased the expression of SAA2 (compared to the 10% tallow group; p<0.05). The porcine SAA2 full length cDNA sequence was cloned and the sequence was compared to the human and mouse sequences. The homology of the SAA2 amino acid sequence between pig and human was 73% and between pig and mouse was 62%. There was a considerable difference in SAA2 sequences among these species. Of particular note was a deletion of 8 amino acids, in the pig compared to the human. This fragment is a specific characteristic for the SAA subtype that involved in acute inflammation reaction. Similar to human and mouse, porcine SAA2 was highly expressed in the liver of pigs. It was not detectable in the skeletal muscle, heart muscle, spleen, kidney, lung, and adipose tissue. These data suggest that SAA2 may be involved in mediation of the function of dietary DHA in the liver of the pig, however, the mechanism is not yet clear.