• Food Science of Animal Resources
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• v.44 no.1
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• pp.87-102
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• 2024

This study aims to compare the chemical composition, quality, and muscle fiber characteristics of cull sows and commercial pigs, investigating the effect of changes in muscle fiber characteristics on pork quality. The proximate composition, color, pH, water-holding capacity (drip loss and cooking loss), protein solubility, total collagen content, and muscle fiber characteristics of cull sows (n=20) and commercial pigs (n=20) pork were compared. No significant differences were found between cull sows and commercial pigs in terms of proximate composition, drip loss, protein solubility, or total collagen content of their meat (p<0.05). However, cull sow pork exhibited a red color and a higher pH (p<0.05). This appears to be the result of changes in muscle fiber number and area composition (p<0.05). Cull sow meat also displayed better water-holding capacity as evident in a smaller cooking loss (p<0.05), which may be related to an increase in muscle fiber cross-sectional area (p<0.05). In conclusion, muscle fiber composition influences the pork quality; cull sow pork retains more moisture when cooked, resulting in minimal physical loss during processing and can offer more processing suitability.

• Journal of Korean Biological Nursing Science
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• v.4 no.2
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• pp.19-40
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• 2002

The purpose of this study was to determine the effect of DHEA on Type I(soleus) and II muscles(plantaris, gastrocnemius) in a focal brain ischemia model rat. Thirty-seven male Sprague-Dawley rats with $200{\sim}250g$ body weights were randomly divided into four groups : CINS(cerebral ischemia + normal saline), CIDH(cerebral ischemia + DHEA), SHNS(sham + normal saline), SHDH (sham + DHEA). Both the CINS and CIDH groups were undergone a transient right middle cerebral artery occlusion operation. In the SHNS and SHDH groups, a sham operation was done. DHEA was administered daily at a dose of 0.34mmol/kg, and normal saline was administered daily at the same dose by intraperitoneal injection for 7days after operation. Cerebral infarction in the CINS and CIDH groups was identified by staining with 2% triphenyltetrazolium chloride solution for 60 minutes. The data were analyzed by Kruskal-Wallis test and Mann-Whitney U test using the SPSSWIN 9.0 program. The results were summarized as follows: 1) The muscle weights of soleus(Type I), plantaris and gastrocnemius(Type II) in CINS group were significantly less than those of the SHNS group(p<.01). The muscle fiber cross-sectional area of the CINS group was significantly less than that of the SHNS group in Type I muscle fiber of the soleus and Type II muscle fiber of the plantaris and gastrocnemius(p<.05). The myofibrillar protein content of the CINS group was significantly less than that of the SHNS group in the left gastrocnemius and right soleus(p<.05). 2) The muscle weights of the soleus, plantaris and gastrocnemius except the unaffected side of the plantaris in the CIDH significantly increased compared to those of the CINS group(p<.05). The muscle fiber cross-sectional area of the CIDH group significantly increased compared to that of the CINS group in Type II muscle fiber of the plantaris and gastrocnemius(p<.05). The myofibrillar protein content of the CIDH group significantly increased compared to that of the CINS group in the left soleus(p<.05). 3) On the post-op 8 day, the body weight of the CINS group was significantly less than that of the CIDH, SHNS and SHDH groups(p<.01). Total diet intake of the CINS and CIDH groups was significantly less than that of the SHNS and SHDH groups(p<.01). Based on these results, it was identified that muscle atrophy could be induced during the 7 days after cerebral infarction, and DHEA administration during the early stage of cerebral infarction might attenuate muscle atrophy.

• Food Science of Animal Resources
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• v.40 no.6
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• pp.957-968
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• 2020

The influence of muscle architecture on muscle fiber characteristics and meat quality has not been fully elucidated. In the present study, muscle fiber characteristics on the chop surface of pork loin (M. longissimus thoracis et lumborum, LTL), pennation angle degree, and meat quality were evaluated to understand the pork LTL architecture and its relationship with the loin chop quality. Muscle fiber pennation degree ranged from 51.33° to 69.00°, resulting in an ellipse-shaped muscle fiber on the surface of pork loin chop. The cross-sectional area (CSA) on the sections cut vertical to the muscle length (M-Vertical) was considerably larger (p<0.05) than that on the sections cut vertical to the muscle fiber orientation (F-Vertical) regardless of the fiber type. Pennation angle is positively correlated with CSAs of F-Vertical (p<0.05) and with Warner-Bratzler shear force (r=0.53, p<0.01). Besides the shear force, lightness and pH were positively correlated with the fiber composition and CSA of IIX fiber (p<0.05); however, the redness, yellowness, drip loss, and cooking loss were not correlated with the pennation angle and muscle fiber characteristics on the chop surface (p>0.05). These observations might help us in better understanding pork loin architecture and the relationship between the pennation angle, muscle fiber characteristics, and meat quality of pork loin chop.

• Food Science of Animal Resources
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• v.44 no.5
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• pp.1181-1194
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• 2024

This study assessed and compared meat quality and fiber characteristics of longissimus lumborum (LL), psoas major (PM), and semimembranosus muscles among Hanwoo (HW), Jeju black (BL), and their crossbred (BH) cattle. Twelve carcasses from each breed (36 in total) were used in this study. BL and BH had higher moisture and crude ash contents and lower crude fat and protein contents than HW, regardless of the muscle type. BL had higher CIE a^*, cooking loss, and shear force values than did the other breeds for all muscle types. The muscle fiber size (cross-sectional area) of BL and BH was larger than that of HW for all muscle types. Type IIX was the dominant muscle fiber type in both BL and BH, regardless of muscle type; however, HW had the highest composition of type I compared to the other types (IIA, IIAX, and IIX) in PM. Higher total fiber density was observed in the LL and PM muscles of HW than in those of BL and BH. Meat quality and muscle fiber characteristics of BL and BH were distinct from those of HW.

• Journal of Korean Academy of Nursing
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• v.44 no.4
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• pp.371-380
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• 2014

Purpose: The purpose of this study was to examine the effects of Cu/Zn SOD on reduction of hindlimb muscular atrophy induced by cisplatin in rats. Methods: Forty-two rats were assigned to three groups; control group, Cisplatin (CDDP) group and cisplatin with Cu/Zn SOD (CDDP-SOD) group. At day 35 hindlimb muscles were dissected. Food intake, activity, withdrawal threshold, muscle weight, and Type I, II fiber cross-sectional area (CSA) of dissected muscles were measured. Relative SOD activity and expression of MHC and phosphorylated Akt, ERK were measured after dissection. Results: Muscle weight and Type I, II fiber CSA of hindlimb muscles in the CDDP group were significantly less than the control group. Muscle weight and Type I, II fiber CSA of hindlimb muscles, food intake, activity, and withdrawal thresholds of the CDDP-SOD group were significantly greater than the CDDP group. There were no significant differences in relative SOD activities of hindlimb muscles between the CDDP-SOD and CDDP groups. MHC expression and phosphorylated Akt, ERK of hindlimb muscles in the CDDP-SOD group were significantly greater than the CDDP group. Conclusion: Cu/Zn SOD attenuates hindlimb muscular atrophy induced by cisplatin through increased food intake and activity. Increment of phosphorylated Akt, ERK may relate to attenuation of hindlimb muscular atrophy.

• Journal of Korean Academy of Nursing
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• v.39 no.3
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• pp.321-328
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• 2009

Purpose: The purpose of this study was to determine the effect of Dehydroepiandrosterone(DHEA) administration alone or exercise combined with DHEA before steroid treatment on rat hindlimb muscles. Methods: Male Sprague-Dawley rats were assigned to one of three groups: a steroid group(S, n=10) that had no treatment for 7 days before steroid treatment; a DHEA-steroid group(DS, n=8) that had 0.34 mmol/kg/day DHEA injection once a day for 7 days before steroid treatment and an exercise+DHEA-steroid group(EDS, n=9) that ran on the treadmill combined with 0.34 mmol/kg/day DHEA injection for 7 days before steroid treatment. At 15 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles were dissected. Body weight, food intake, muscle weight, myofibillar protein content and cross-sectional area of the dissected muscles were determined. Results: The DS group showed significant increases(p<.05) as compared to the steroid group in body weight, and muscle weight of gastrocnemius muscles. The EDS group showed significant increases(p<.05) as compared to the S group in body weight, muscle weight, myofibrillar protein content, and Type II fiber cross-sectional area of soleus, plantaris and gastrocnemius muscles. Conclusion: Exercise combined with DHEA administration before steroid treatment prevents steroid induced muscle atrophy, with exercise combined with DHEA administration being more effective than DHEA administration alone in preventing muscle atrophy.

• Biomolecules & Therapeutics
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• v.31 no.5
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• pp.573-582
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• 2023

Muscle atrophy is characterized by the loss of muscle function. Many efforts are being made to prevent muscle atrophy, and exercise is an important alternative. Methylglyoxal is a well-known causative agent of metabolic diseases and diabetic complications. This study aimed to evaluate whether methylglyoxal induces muscle atrophy and to evaluate the ameliorative effect of moderate-intensity aerobic exercise in a methylglyoxal-induced muscle atrophy animal model. Each mouse was randomly divided into three groups: control, methylglyoxal-treated, and methylglyoxal-treated within aerobic exercise. In the exercise group, each mouse was trained on a treadmill for 2 weeks. On the last day, all groups were evaluated for several atrophic behaviors and skeletal muscles, including the soleus, plantaris, gastrocnemius, and extensor digitorum longus were analyzed. In the exercise group, muscle mass was restored, causing in attenuation of muscle atrophy. The gastrocnemius and extensor digitorum longus muscles showed improved fiber cross-sectional area and reduced myofibrils. Further, they produced regulated atrophy-related proteins (i.e., muscle atrophy F-box, muscle RING-finger protein-1, and myosin heavy chain), indicating that aerobic exercise stimulated their muscle sensitivity to reverse skeletal muscle atrophy. In conclusion, shortness of the gastrocnemius caused by methylglyoxal may induce the dynamic imbalance of skeletal muscle atrophy, thus methylglyoxal may be a key target for treating skeletal muscle atrophy. To this end, aerobic exercise may be a powerful tool for regulating methylglyoxal-induced skeletal muscle atrophy.

• The Korea Journal of Herbology
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• v.38 no.5
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• pp.31-37
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• 2023

Objective : This study was conducted to investigate the muscle-improving and therapeutic effects of Boehmeria platanifolia (BP) in a mouse model of dexamethasone-induced muscle atrophy. Methods : Muscle atrophy was induced in C57BL/6 mice by intraperitoneal administration of dexamethasone for 12 days. BP extract was administered orally at doses of 100 mg/kg and 200 mg/kg for 19 days, starting 7 days before the intraperitoneal administration of dexamethasone. Mice were weighed during the experimental period, and muscle strength and muscle weight were measured at the end of the experiment. The gastrocnemius (GASTROC) muscles of mice were isolated and the cross-sectional area (CSA) of the muscle fibers was measured after H&E staining. Results : Dexamethasone-induced muscle atrophy mice had a decrease in body weight compared to normal mice, and BP-administrated mice did not show significant change in body weight compared with a control group. Muscle strength in mice with induced muscle atrophy was reduced compared to normal and significantly increased with BP administration and positive control. In addition, the weight of the quadriceps (QUAD) muscle and fiber size of the GASTROC muscle, which was reduced in sarcopenia-induced mice, was increased by BP. Conclusion : BP extract increased muscle strength, muscle weight, and muscle fiber size in dexamethasone-induced muscle atrophy mice. This suggests that the efficacy of BP extracts in improving muscle strength and preventing and treating sarcopenia may be beneficial for the development of potential therapeutic or functional products.

• Journal of Korean Biological Nursing Science
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• v.14 no.1
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• pp.49-56
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• 2012

Purpose: The purpose of this study was to compare the effects of anorexia induced by consecutive low-dose and high-dose of cisplatin (CDDP) on the hindlimb muscles of rats. Methods: Male Sprague-Dawley rats were assigned to three groups: Control group (C) received a saline (the same dose and duration as the low CDDP group), the high-dose cisplatin (High CDDP) group received a single 5 mg/kg dose of cisplatin, the consecutive low-dose cisplatin (Low CDDP) group had 1 mg/kg of cisplatin administered for five consecutive days. On the 8th day the soleus and gastrocnemius muscles were dissected. Body weight, food intake, activity, muscle weight, Type I, II fiber cross-sectional area (CSA) of the dissected muscles were measured. Results: Body weight, food intake, muscle weight and Type I, II fiber CSA of the High CDDP and Low CDDP groups were significantly less than the C group. The High CDDP group showed significant decreases, compared to the Low CDDP group, in body weight, food intake, activity score, muscle weight and Type I, II fiber CSA. Conclusion: Hindlimb muscle atrophy occurs due to anorexia induced by both consecutive low-dose and high-dose cisplatin. The muscle atrophy induced by consecutive low-dose cisplatin is less apparent than high-dose cisplatin.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.12 no.1
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• pp.57-67
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• 2006

Musculoskeletal neck dysfunction syndromes are common in outpatient musculoskeletal pain practice. The underlying musculoskeletal and neurologic causes of pain are variable. In the management of these patients, it is important to accurately identify and treat these pain generators to optimize patient outcome. It is the purpose of this review to discuss three main categories of functional anatomy, the role of superficial/deep muscular system and the scientific evidence for optimal physical therapy intervention for cervical dysfunction. Specifically there is evidence of lowered microcirculation in the upper trapezius muscle, morphological signs of disturbed mitochondrial function which appears to be limited to type I fibers and an increased cross-sectional area of type I muscle fibers despite a lower capillary to fiber area ratio. In acute neck pain syndrome, changes in muscle activity of painful muscles may result from segmental and supraspinal inhibitory effects. Muscle activation is closely related to the control of joint movements and postures and it is difficult to separate the influence of the two components. Both the altered muscle recruitment patterns and altered kinematics appear to be a poor adaptation for pain of the head - neck region, as they are likely to result in increased compressive loading in the cervical spine, affecting muscles, articular structures such as zygapophyseal joints, connective tissues and neural tissues which are all peripheral generators of referred pain. The rectus capitus posterior minor muscle shows that it is one of the most important muscles of the suboccipital region. In this article, i reviewed the anatomy, neurophysiology, function and dysfunction as well as the treatment of cervical dysfunction.