• Korean Journal of Agricultural Science
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• v.45 no.1
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• pp.50-57
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• 2018

Meat comes from the skeletal muscles of farm animals, such as pigs, chickens, and cows. Skeletal muscles are composed of many muscle fibers. Muscle fibers are categorized into three types, fiber type I, IIA, and IIB, based on their contractile speed and metabolic properties. Different muscle fiber types have different biochemical, physiological, and biophysical characteristics. Especially, the characteristics of muscle fiber type I and IIB are opposite to each other. Muscle fiber type I has a relatively strong oxidative metabolic trait and a higher content of lipids. In contrast to fiber type I, muscle fiber type IIB has a strong glycolytic metabolic trait and a relatively lower content of lipids and a higher content of glycogen. Muscle fiber type IIA has intermediate properties between fiber type I and IIB. Thus, muscles with different fiber type compositions exhibit different ante- and post-mortem muscle characteristics. In particular, the different metabolic traits of muscles due to the different compositions of the fiber types strongly affect the biochemical and physiological processes during the conversion of muscle to meat and subsequently influence the quality of the meat. Therefore, understating muscle metabolism and muscle fiber characteristics is very important when discussing the traits of meat quality. This review is an overview on basic muscle metabolism, muscle fiber characteristics, and their influence on meat quality and finally provides a comprehensive understanding about the fundamental traits of muscles and meat quality.

• Journal of Acupuncture Research
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• v.18 no.1
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• pp.170-185
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• 2001

Objective : This experimental study was designed to investigate the effect of Chaenomelis fructus herbal acupuncture on the soleus muscle and tibialis anterior muscle of hindlimb-suspended rats. The measurement have been performed on the composition of type I, type IIa and type IIb muscle fibers in the soleus muscle and tibialis anterior muscie - histochemical study. Materials and Methods : Sprague-Dawley rats weighing about 250g were subjected to hindlimb suspension and divided into six groups; 1. Normal group: normai group 2. Control group: group of hindlimb suspension for 7 days 3. NT group: non-treatment group for 2 or 4 weeks after 7days of hindlimb suspension. 4. EX gtoup: running exercise group for 2 or 4 weeks after 7days of hindlimb suspension. 5. HA group: administration of Chaenomelis fructus herbal acupuncture during 2 or 4 weeks after 7 days of hindlimb suspension. 6. EXHA group: administration of Chaenomelis fructus herbal acupuncture and running exercise during 2 or 4 weeks after 7 days of hindlimb suspension. Results Results : 1. The composition of type I muscle fibers in the soleus muscle significantly increased in 2 or 4 weeks HA and EXHA groups more than control group, and the composition of type IIa muscle fibers in the soleus muscle significantly decreased in 2 or 4 weeks HA and EXHA goups more than control group. 2. The composition of type I muscie fibers in the tibialis anterior muscle significantly increased in 2 or 4 weeks HA and EXHA groups more than control group, and the composition of type IIb muscle fibers in the soleus muscle significantly decreased in 2 or 4 weeks HA and EXHA groups more than control group. 3. The size of type I muscle fibers in the soleus muscle significantly increased in 2 or 4 weeks HA and EXHA groups more than control group, and the size of type IIa muscle fibers in the soleus muscle significantly increased in 2 weeks EXHA group and 4 weeks HA and EXHA groups more than control group. 4. The size of type I, IIa muscle fibers in the tibialis anterior muscle significantly increased in 2 or 4weeks HA, EXHA and EX groups more than control group, and the size of type IIb muscle fibers significantly increased in 2 weeks EXHA group and 4 weeks HA, EXHA and EX groups more than control group. 5. The capiliaries number per fiber of muscle fibers in the soleus and tibialis anterior muscle showed no differences in all experimental groups more than control group. Conclusion : According to the above results, it is shown that Chaenomelis fructus herbal acupuncture could be effective in the treatment of muscle atrophy.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.1 no.2
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• pp.21-30
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• 2003

The purpose of this study was to know the effect of aquatic-exercise on muscle atrophy which induced by steroid injection. The forty-eight Sparague-Dawley adult male rats were assigned to the 4 groups; GroupI(distilled water injection), GroupII(steroid injection), GroupIII(distilled water injection and aquatic exercise), GroupIV(steroid injection and aquatic exercise). We observed their body weight, histological change by PAS stein. The results of this study were as follows; 1. After 2 weeks, the change of weights appeared that non-steroid injection groups increase weight and steroid injection groups decreased weight hasty. after 4 weeks, weights recovered from weight before test. It was possible to explain the change of weight by type II muscle fiber increase. 2. In histological change of muscle fibers, atrophy didn't observed in test group I, because type II muscle fibers were developed well. we observed not only injury of muscle fiber and muscle atrophy but specifically grouping type I muscle fiber in test group II. normal arrangement of muscle fibers were visible in test group and type II muscle fibers increased. we could observe muscle recovery because of type II muscle fibers increase in test group IV. therefore, it was seem that type II cell was recovering through aquatic exercise.

• Journal of Korean Academy of Nursing
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• v.26 no.2
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• pp.271-280
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• 1996

The purpose of this study was to determine the effect of periodic walking during hindlimb suspension on the mass, relative weight, fiber type distribution and cross-sectional area of Type I and II fibers in the developing Type II plantaris muscle. To examine the effectiveness of periodic walking on mass and fiber size, the hindlimbs of young female Wistar rats were suspended (HS group) and half of these rats walked on a treadmill for 45 min／day(15 min every 4 hours) at 5 meters／min at a 15 degree grade(HS-W group) After seven days of hindlimb suspension, the plantaris muscle wet weight was 28.40％ significantly smaller（P＜0.005） and relative plantaris muscle weight was 26.97％ smaller compared with those of control rats（P＜0.05）. The plantaris muscle wet weight and the relative plantaris muscle weight increased by 46.60％ and 49.23％ respectively with periodic walking, moreover. the plantaris muscle wet weight and the relative plantaris muscle weight of the HS-W rats recovered to the level of the control rats. No change was observed in fiber type percentage of the developing plantaris muscle following one week of hindlimb suspension or periodic walking during hindlimb suspension. Type I and II fiber cross-sectional areas of the developing plantaris muscle were 42.51％ and 43. 68％ lower in the HS group than in the control group（p＜0.0001）, Type I and II fiber cross-sectional areas of the developing plantaris were 30.82％ and 45.97％ greater in the HS-W group than in the HS group（p＜0.0001）, whereas Type I and II fiber cross-sectional area of HS-W group were less than those of the control group（P＜0.0001） The results suggest that periodic walking can attenuate developing plantaris muscle atrophy induced by hindlimb suspension.

• Journal of Animal Science and Technology
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• v.66 no.2
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• pp.251-265
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• 2024

Meat derived from skeletal muscles of animals is a highly nutritious type of food, and different meat types differ in nutritional, sensory, and quality properties. This study was conducted to compare the results of previous studies on the muscle fiber characteristics of major porcine skeletal muscles to the end of providing basic data for understanding differences in physicochemical and nutritional properties between different porcine muscle types (or meat cuts). Specifically, the muscle fiber characteristics between 19 major porcine skeletal muscles were compared. The muscle fibers that constitute porcine skeletal muscle can be classified into several types based on their contractile and metabolic characteristics. In addition, the muscle fiber characteristics, including size, composition, and density, of each muscle type were investigated and a technology based on these muscle fiber characteristics for improving meat quality or preventing quality deterioration was briefly discussed. This comparative review revealed that differences in muscle fiber characteristics are primarily responsible for the differences in quality between pork cuts (muscle types) and also suggested that data on muscle fiber characteristics can be used to develop optimal meat storage and packaging technologies for each meat cut (or muscle type).

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.428-433
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• 2004

The aim of this study was to investigate the histochemical parameters of muscle fibers, and to estimate the correlation between these histological parameters and carcass traits in pigs. A total of 230 crossbred Duroc$\times$(Yorkshire$\times$Landrace) pigs (149 gilts and 81 castrated male pigs) was evaluated. Carcass traits (carcass weight, backfat thickness, and loin eye area), muscle fiber size (crosssectional area, diameter, and perimeter), muscle fiber number (density of fibers/$mm^2$ and total number of fibers), and fiber type composition (percentages of myofibers and relative areas of each fiber type) were evaluated. Mean cross-sectional area (CSA) and type IIB fiber CSA were positively correlated to carcass weight, backfat thickness and loin eye area. Mean fiber CSA was mostly related to type IIB CSA (r=0.98) as a result of the high percentage of type IIB fibers in the longissimus muscle. Correlations between fiber diameters and perimeters were also high, and showed similar results with CSA. Mean fiber density was negatively correlated to carcass weight (r=-0.24), backfat thickness (r=-0.18) and loin eye area (r=-0.27). To the contrary, total fiber number was positively correlated with carcass weight (r=0.27) and loin eye area (r=0.53). Carcass weight and loin eyZe area were not significantly related to muscle fiber composition. For backfat thickness, there was an opposition between type IIA percentage, which was positively related and type IIB percentage, which was negatively related. Fiber type composition of type I and IIA fibers were negatively correlated to that of type IIB fibers (r=-0.67 to -0.74). In the present study, carcass weight and loin eye area were positively correlated to CSA and negatively correlated to fiber density. But, these relationships were generally low. The fiber density was strongly affected by muscle fiber size and the total fiber number was affected either by CSA of muscle fiber and loin eye area. Fiber type composition was much more related to their numerical abundance than their CSA.

• Journal of Chest Surgery
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• v.25 no.9
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• pp.936-942
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• 1992

There are three types of papillary muscle of the left ventricle[finger, tethered and mixed type] according to the morphology of the attachment to the ventricular wall. Especially finger type of the papillary muscle is more vulnerable to the injury than tethered or mixed type, because their blood supply is dependent upon the central artery whose diameter is less than 1mm and the papillary muscle itself is the end organ of the heart anatomically. There are several causes of papillary muscle rupture but few cases have been reported. Recently we have experienced 3 cases of papillary muscle rupture of the left ventricle with successful mitral valve replacement and the causes are postmyocardial infarction, percutaneous mitral valvulotomy and non-penetrating chest trauma. The common finding is the morphology of papillary muscle, that is the finger type and their rupture type is the complete type.

• Fashion & Textile Research Journal
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• v.25 no.2
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• pp.185-198
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• 2023

The purpose of this study is to obtain information necessary for the development of patient clothes that can reduce physical fatigue of caregivers by quantitatively measuring the muscle load and fatigue. The patient clothes used in this study can be broken down into three types: A type (back center zipper open suit), B type (top-to bottom separated patient clothes), and C type (front zipper open suit). The EMG measurement sites are as follows: hand muscle (brachioradialis), upper arm (biceps, triceps), shoulder (anterior deltoid, medial deltoid, posterior deltoid, upper trapezius), and waist (erector spinae); additionally, the EMG signals were measured. Through this experiment, muscle load, muscle energy consumption, and muscle fatigue generation tendency were analyzed. The results of the study revealed that the C type patient clothes required the most strength in the muscles of the shoulders, upper arms, hands, and back when being put on and taken off compared to other patient clothes. The A type clothes required a relatively large force in opening the zipper. In terms of muscle energy consumption, B type generally called for more strength when it came to the zip-up and putarmsup motions. With regard to the cover the body and put legs/hips up motions, C type used the highest amount of muscle energy, whereas A type used relatively little energy. In terms of the occurrence of muscle fatigue during the putting on and taking off of the patient's clothing, there was a difference in the area and degree of muscle fatigue in the A, B, and C types, and there was also a tendency for muscle fatigue to occur when performing repetitive movements.

• Korean Journal of Food Science and Technology
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• v.18 no.3
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• pp.181-186
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• 1986

Myosin were prepared from red muscle and white muscle, and their ATPase activities were compared. Ca-ATPase activity of bovine myosin from red muscle was higher than that of myosin from white muscle, while Ca-ATPase activity of chicken myosin from red muscle differed hardly from that of myosin from whitemuscle. Atso EDTA-ATPase activity of bovine red muscle myosin was higher than that of white muscle myosin ,although EDTA-ATPase activity of chicken myosin from red muscle differed hardly from that of white muscle myosin. When myosins were treated with trypsin, bovine myosin from white muscle was hydrolysed moreeasily than red muscle myosin was. Chicken myosin from red muscle , however, was hydrolysed by trypsin more easily than white muscle myosin was.

• Animal Bioscience
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• v.36 no.2_spc
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• pp.374-384
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• 2023

Skeletal muscle metabolism regulates homeostatic balance in animals. The metabolic impact persists even after farm animal skeletal muscle is converted to edible meat through postmortem rigor mortis and aging. Muscle metabolites resulting from animal growth and postmortem storage have a significant impact on meat quality, including flavor and color. Metabolomics studies of postmortem muscle aging have identified metabolisms that contain signatures inherent to muscle properties and the altered metabolites by physiological adaptation, with glycolysis as the pivotal metabolism in postmortem aging. Metabolomics has also played a role in mining relevant postmortem metabolisms and pathways, such as the citrate cycle and mitochondrial metabolism. This leads to a deeper understanding of the mechanisms underlying the generation of key compounds that are associated with meat quality. Genetic background, feeding strategy, and muscle type primarily determine skeletal muscle properties in live animals and affect post-mortem muscle metabolism. With comprehensive metabolite detection, metabolomics is also beneficial for exploring biomarker candidates that could be useful to monitor meat production and predict the quality traits. The present review focuses on advances in farm animal muscle metabolomics, especially postmortem muscle metabolism associated with genetic factors and muscle type.