• Journal of Animal Science and Technology
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• v.64 no.2
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• pp.330-342
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• 2022

We aimed to investigate candidate proteins related to long-term caloric restriction and feed efficiency in bovine longissimus dorsi muscle (LM). A total of 31 Korean native steers were randomly distributed to ad libitum (n = 16) or caloric restriction group (n = 15) to conduct two feeding trials for 13 mon. In the first trial (10-18 mon of age), steers were fed with 100% ad libitum (NE_g = 0.63 Mcal/kg) or caloric restriction (80% of the previous day's feed intake of ad libitum group). In the second trial (18-23 mon of age), the energy value of 100% ad libitum diet was 1.13 Mcal/kg NE_g and those in caloric restriction group diet was 0.72 Mcal/kg NE_g. At the endpoint of this experiment, in each group, 6 animals were selected with high (n = 3) or low feed efficiency (n = 3) to collect muscle tissue samples (6 animals/group). From muscle tissues of 23 mo of age, we excavated 9 and 12 differentially expressed (two-fold or more) proteins in a nutritional group and feed efficiency group using two-dimensional electrophoresis, respectively. Of these proteins, heat shock protein beta-6 was up-regulated in both the caloric restriction and the low feed efficiency group. In bovine embryonic fibroblasts, the mRNA expression of heat shock protein beta-6 increased after adipogenic differentiation, however, decreased after myogenic differentiation. Our data provide that heat shock protein beta-6 may be an adipogenic protein involved in the mechanism of caloric restriction and feed efficiency in the LM of the steer.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4329-4337
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• 2022

Jet impinging device is designed for decay heat removal on horizontal fuel rods in a low temperature heating reactor. An experimental system with a fuel rod simulator is established and experiments are performed to evaluate water film covering capacity, within 0.0287-0.0444 kg/ms mass flow rate, 0-164.1 kW/m² heating flux and 13.8-91.4℃ feeding water temperature. An effective method to obtain the film coverage rate by infrared equipment is proposed. Water film flowing patterns are recoded and the film coverage rates at different circumference angles are measured. It is found the film coverage rate decreases with heating flux during single-phase convection, while increases after onset of nucleate boiling. Besides, film coverage rate is found affected by Marangoni effect and film accelerating effect, and surface wetting is significantly facilitated by bubble behavior. Based on the observed phenomenon and physical mechanism, dry-out depth and initial dry-out rate are proposed to evaluate film covering potential on a heating surface. A model to predict film coverage rate is proposed based on the data. The findings would have reliable guide and important implications for further evaluation and design of decay heat removal system of new reactors, and could be helpful for passive containment cooling research.

• Animal Bioscience
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• v.36 no.6
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• pp.920-928
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• 2023

Objective: Angora rabbits fed a low-protein diet exhibit decreased hair production performance. This study was set out to evaluate the effects of methionine on hair properties and nitrogen metabolism in Angora rabbits fed a low-protein diet and to investigate the gene expression related to hair follicle development to determine the possible molecular mechanism of methionine effects on hair follicle development. Methods: An experiment was conducted to investigate the effects of DL-methionine addition on a low-protein diet on hair development in Angora rabbits. Angora rabbits were divided into 5 groups: fed a normal diet (control), fed a low-protein diet (LP), or fed an LP supplemented with 0.2%, 0.4%, or 0.6% DL-methionine (Met). Results: The results showed that rabbits in the LP group had lower wool yield than the control rabbits, but the addition of 0.4% to 0.6% Met to LP attenuated these effects (p<0.05). Dietary addition of 0.4% to 0.6% Met to LP increased the apparent nitrogen digestibility, nitrogen utilization rate, and feed efficiency (p<0.05). Feeding LP decreased the insulin-like growth factor 1 (IGF1), keratin-associated protein (KAP) 3.1, and KAP 6.1 mRNA levels compared with the control, but the addition of 0.4% Met in LP attenuated these effects (p<0.05). Relative to the LP or control group, dietary addition of 0.4% Met increased versican mRNA levels. Conclusion: In conclusion, the addition of Met to LP could improves wool production performance and feed efficiency and reduce nitrogen emissions in Angora rabbits. Met can promote hair follicle development, which may be associated with IGF1, KAP, and the versican signaling.

• Biomolecules & Therapeutics
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• v.31 no.4
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• pp.417-424
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• 2023

Parkinson's disease (PD) which has various pathological mechanisms, recently, it is attracting attention to the mechanism via microbiome-gut-brain axis. 6-Shogaol, a representative compound of ginger, have been known for improving PD phenotypes by reducing neuroinflammatory responses. In the present study, we investigated whether 6-shogaol and ginger attenuate degeneration induced by Proteus mirabilis (P. mirabilis) on the intestine and brain, simultaneously. C57BL/6J mice received P. mirabilis for 5 days. Ginger (300 mg/kg) and 6-shogaol (10 mg/kg) were treated by gavage feeding for 22 days including the period of P. mirabilis treatment. Results showed that 6-shogaol and ginger improved motor dysfunction and dopaminergic neuronal death induced by P. mirabilis treatment. In addition, they suppressed P. mirabilis-induced intestinal barrier disruption, pro-inflammatory signals such as toll-like receptor and TNF-α, and intestinal α-synuclein aggregation. Moreover, ginger and 6-shogaol significantly inhibited neuroinflammation and α-synuclein in the brain. Taken together, 6-shogaol and ginger have the potential to ameliorate PD-like motor behavior and degeneration of dopaminergic neurons induced by P. mirabilis in mice. Here, these findings are meaningful in that they provide the first experimental evidence that 6-shogaol might attenuate PD via regulating gut-brain axis.

• Journal of Life Science
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• v.21 no.11
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• pp.1607-1611
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• 2011

To analyze the role of Bombyx mori transferrin (BmTf) in response to microbes or oxidative stress, we investigated the level of BmTf transcripts in B. mori treated with various microbes and oxidative stress inducers. BmTf mRNA was mainly expressed in the epidermis and fat in the bodies of B. mori injected with Escherichia coli, and up regulated in response to microbes such as bacteria, fungi, or viruses, but was hardly altered in response to oxidative stress inducers such as $H_2O_2$, Cu, or $FeCl_3$. We also confirmed that BmTf mRNA expression was increased in Bm5 cells treated with ERK, PLC, PKA, PI3K, MAPK, or JNK inhibitors, respectively. To identify the major inducer of BmTf expression, we analyzed the amount of serum iron in the hemolymph of B. mori after injection or feeding with E. coli or $FeCl_3$. The results showed that the amount of serum iron was not changed by injection and feeding with E. coli, although BmTf mRNA was increased by injection with E. coli. On the contrary, injection and feeding with $FeCl_3$ significantly increased the amount of serum iron, although they did not alter the BmTf mRNA level. On the basis of these results, we assume that up-regulation of BmTf in B. mori is closely related to the defense of microorganism, and BmTf may be expressed at the basal constitutive level when it plays a role in iron metabolism by maintaining iron homeostasis and in the insect defense mechanism against oxidative stress.

• Korean journal of applied entomology
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• v.24 no.2 s.63
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• pp.51-60
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• 1985

This paper was performed to study the nature of varietal resistance of some Korean-new rice cultivars to the brown planthopper (BPH), Nilaparvata lugens ($ST{\AA}L$). The rice cultivars tested were Cheongcheong, Gaya, Hangangchal, Samgang, Nampoong and Yeongpoong which have been reported as having resistant genes for the BPH. The check varieties were Jinheung, Sangpoong and Chucheong for susceptible and IR-36 for resistant. The factors studied were referred to the seedling responses, preference in feeding and oviposition of BPH, antibiosis (nymphal development, adult emergence and sex ratio, adult body weight, population build-up, feeding amount and amylase activity), and chemical composition (inorganic components, chlorophyll contents, cell wall components, amino acids and esterase isozymes) of leaf- sheath and/or roots of rice plants. In conclusion, the natures of varietal resistance of rice cultivars to the BPH were not only correlated with the resistant reaction of rice plant, but also they were related with the non preference in feeding and oviposition and those resistant cultivars had the antibiotic effects to the insects. Their antibiotic effects of rice cultivars to the BPH would be related with some of the chemical components of rice plants, such as the contents of magnesium oxide (MgO), and chlorophyll and the different esterase isozymes.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.330-335
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• 2007

This study was performed to investigate the anti-diabetic mechanism of crude polysaccharides isolated from the fruiting bodies of Grifola frondosa. We treated 3T3-L1 adipocyte cells to observe whether the crude polysaccharides isolated from Grifola frondosa would stimulate insulin sensitivity. Significant insulin sensitizing activity was observed in the 3T3-L1 adipocytes, and giving the crude polysaccharide of Grifola frondosa with 1 nM of insulin caused glucose uptake to increase to a similar level as giving 50 nM of insulin alone. To confirm the mechanism for the anti-diabetic effect of the crude polysaccharides, we performed further examinations within $KK-A^{y}$ mice, an animal model of type 2 diabetes. The crude polysaccharides reduced blood glucose levels in the $KK-A^{y}$ mice for 2 weeks after feeding, and also significantly lowered plasma insulin levels. These results suggest that the anti-diabetic mechanism of the crude polysaccharide of Grifola frondosa is related to the enhancement of insulin sensitivity.

• Journal of Nutrition and Health
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• v.31 no.5
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• pp.897-905
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• 1998

Docosahexaenoic acid(DHA), a $\omega$3 series fatty acid and arachidonic acid(AA). a $\omega$6 series fatty acid were found in relatively high concentrations in the phospholipids(PLs) of cell membranes of nerve tissues, and they can be affected by various factors. The present study examined the effects of dietary $\omega$6 and $\omega$3 fatty acid composition on P/M/S and on $\omega$3/$\omega$6 fatty acid ratios in brain PLs of 2nd generation rats. The expeimental diets consisted of 10% fat(by wt), which were computer- searched mixed oil('M') with P/M/S ratio, 1 : 1.4 : 1 and $\omega$6/$\omega$3 ratio, 6 : 1 and safflower oil('S') poor in $\omega$3 fatty acids. The experimental diets were started 3-4 wks prior to conception. During the lactation period, the feeding mothers were switched 1 wk after birth and provided the pups for 2 wks with milk which had compositions different from that of their natural mother. The same diet as their mothers was provided from weaning to 9 wks of age. The 'M'and 'S' rats were again subdivided into MM, MS, SS, SM rats according to diet which their lactating mothers were fed from the begining of the experiment. The relative percentage of P/M/S fatty acids in brain PLs in all experimental groups converged to a very similar value at 9 wks of age, indicating the existence of a control mechanism for the degree of fatty acids, unsaturation. The $\omega$3/$\omega$6 fatty acid ratios of brain PLs converged to about 1.0 in MM & SM groups and to 0.7 in SS & MS groups, suggesting also the existence of some balance between $\omega$3 and $\omega$6 fatty acids in developing rat brain. The concentrations of $\omega$3 fatty acids, especially DHA, in the SM group were increased and became similar to those in MM group at 9 wks of age. The increase in DHA of brain PLs was counterbalanced b)r a decrease in 22 5$\omega$6. Therefore, the ratios of 22 : 6$\omega$6/22 : 5$\omega$6 were higher in both MM & SM groups than those of SS & MS groups at 9 wak of age. Although dietary $\omega$3 and $\omega$6 fatty acids affected 22 : 6$\omega$S and 22 : 5$\omega$6 contained in rat brain PLs reciprocally, the relative percentage of AA did not appear to be significantly influenced by the diet in all groups at 9 wks of age, suggesting that a mechanism for the maintenance of a certain level of AA in brain PLs exists. In conclusion, the $\omega$3/$\omega$6 fatty acid and 22 : 6$\omega$3/22 : 5$\omega$6 ratios, but not P/M/S ratio, of rat brain PLs were affected by the postnatal dietary changes. Futher studies are required to clarify the mechanism(S) of ensuring a certain level of DHA and of maintaining a similar level of AA in rat brain PLs after. weaning(9 wk) regardless of prenatal and postnatal dietary changes. (Korean J Nutrition 31(5) : 897-905, 1998)

• Journal of Nutrition and Health
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• v.36 no.9
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• pp.898-907
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• 2003

Antioxidative function of uncooked powdered food (Sangsik) was evaluated in rats consuming nutritionally unbalanced diet including 1％ cholesterol, high proportion of animal lipids (lard : soybean oil : 8 . 2) , sub-optimal levels of vitamin and mineral mixture along with 0.5% ethanol in drinking water. The uncooked powdered food tested in the present study was a mixture composed of 42 kinds of plant foods (cereals, legumes, seaweeds, vegetables, and fruits) supplemented with vitamins and minerals, and dietary fiber. Control rats were fed the semi-purified diet based on the AIN-93G composition, and nutritionally unbalanced rats were divided into 3 groups, and fed one of the following diets with 0.5% ethanol in drinking water for 5 weeks : unbalanced control diet (UC) ,20% Sangsik powder supplemented diet (S20), and 40% Sangsik powder supplemented diet (S40) . Food efficiency ratio was significantly higher in rats fed S40 compared to the value for rats fed UC (p < 0.05). Hepatic level of thiobarbituric acid reactive substances (TBARS) was significantly lower in rats fed UC compared to that for control rats (p < 0.05) , and was not influenced by dietary supplementation of the Sangsik powder. Hepatic superoxide dismutase (SOD) activity was significantly higher in rats fed UC compared to that for control rats (p < 0.05) , and significantly reduced in rats fed S20 or S40 compared to the value for unbalanced control rats. Feeding unbalanced control diet significantly reduced the ratio of hepatic GSH-Px ＋ catalase/SOD activities compared to the value for control rats, and this decrease in the ratio of antioxidant enzyme activities was reversed by adding the Sangsik powder to the diet at 20% (p <0.05) . Based on the results of antioxidant enzyme activities, feeding uncooked powdered diet appears to provide a favorable environment for body's antioxidative defense mechanism. Serum levels of Fe and Cu were significantly lower in rats fed the Sangsik powder supplemented diets compared to the value for unbalanced control rats (p < 0.05) , and levels of Se, Mn, and Zn were also tended to be decreased by dietary supplementation of the Sangsik powder. These results postulate the possibility that ingredients used in the uncooked powdered food may decrease the bioavailability of trace elements in rats.

• Korean journal of food and cookery science
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• v.21 no.5
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• pp.725-732
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• 2005

This study attempted to investigate if the soy isoflavone, genistein, influences bone metabolism in ovariectomized, 4-week-old female Wister rats. All the rats were divided into sham (SH) and ovariectomized (OVX) groups consisting of OVX-17${\beta}$-estradiol($10\;{\mu}g/kg$ b.w.), OVX-1mg or 5 mg or 10mg of genistein/kg b.w. The rates were allowed ad libitum access to foods and water for 8 weeks. The Results showed that body weight had significantly increased in the OVX group compared to the SH group (p<0.05) and was not different among the OVX-GEN and OVX-ES groups and the OVX group. The liver and uterus weights in the OVX groups were slighter than those in SH group (p<0.05). The kidney weight in the OVX groups was decreased compared to in that in the SH group but was not significantly different among all OVX groups. Femoral length in the OVX groups was longer than in the SH group and was not different. Rats in the OVX groups had higher creatinine levels than those in the SH group and hydroxyproline level did not differ significantly among any of the groups. Serum ALP activity and Ca in bone, feces, urine and serum did not change among the groups. Bone mineral density (BMD) decreased in the OVX groups compared to the SH group and was slightly increased by feeding genistein (p>0.05). Breaking force and stiffness did not change by ovariectomy and feeding genistein. Hence, these results suggested that estrogen may affect bone mineralization in growing rats and that genistein be may involved in the prevention of bone loss. However, more studies are needed to identify the proper mechanism of genistein and bone formation.