• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.1
• /
• pp.81-86
• /
• 2002

The present study was conducted to investigate the effect of dietary supplementation of vitamin A or $\beta$-carotene on oxidative damage induced by acute ethanol administration. Sprague-Dawley rats were fed on the experimental diets supplemented with retinyl acetate (2.86 mg/kg diet) or $\beta$-carotene (15.2 mg/kg diet) for 5 weeks. After fed the diet, rats were administered 20% ethanol solution (3g/kg B.W.) acutely. Lipid peroxide values in hepatic tissue, hepatic antioxidative enzyme activities and contents of antioxidative nutrient such as vitamins A and E in serum and hepatic tissue were measured. Hepatic level of malondialdehyde decreased in $\beta$-carotene group compared to the control group. However, there was no significant difference between retinal acetate and $\beta$-carotene groups. Superoxide dismutase activity was higher in retinal acetate group than in the control group. Hepatic glutathione-S-transferase activity of retinal acetate and $\beta$-carotene groups significantly decreased as compared with that of control group. The hepatic content of retinol increased in retinal acetate and $\beta$-carotene groups, especially, in retinyl acetate group. But there was no significant difference in serum content of retinol among the groups. Hepatic content of $\alpha$-tocopherol was significantly increased in retinyl acetate and $\beta$-carotene groups. In conclusion, acute ethanol administration might induce lipid peroxidation, and the dietary supplementation of retinyl acetate or $\beta$-carotene improve partly the antioxidative system through activation of superoxide dismutase and retention of hepatic $\alpha$-tocopherol in ethanol-treated rats.

• Korean Journal of Environmental Agriculture
• /
• v.25 no.4
• /
• pp.339-345
• /
• 2006

Accumulation of nitrate in green vegetables is undesirable due to potential risks to human health. Lettuce was cultivated in pots under greenhouse conditions with compost applications of 2,000 and 4,000 kg/10a, and the growth and nitrate accumulation of lettuce were compared with those found in the lettuce cultivated with chemical fertilizers of recommended levels. Content of $NH_4-N$ in the soils of compost applications were much lower than those found in the soil of chemical fertilizer application. Two weeks after lettuce transplant $NH_4-N$ was not found in the soils of compost applications, and in the soils of chemical fertilizers application $NH_4-N$ was not found three weeks after lettuce transplant. One week after lettuce transplant content of $NO_3-N$ was much higher in the soils of compost applications, and the contents were rapidly decreased. While, the content of $NO_3-N$ in the soil of chemical fertilizers application was rapidly increased due to the nitrification of $NH_4$ released from the applied urea. At the time of harvest contents of $NO_3-N$ in the soils of compost applications were less than 1.4 mg/kg, but in the soil of chemical fertilizers application the content of $NO_3-N$ was 54.2 mg/kg. Contents of $NH_4$ in lettuce were about 20 mg/kg FW and were not much different among the treatments. However, contents of $NO_3$ in lettuce were significantly different between the treatments of chemical fertilizer and compost. There were significant differences in fresh and dry weights, and growth of lettuce in the compost treatment of 4,000 kg/10a was highest among the treatments. These results indicate that the cultivation with compost only as N source can produce higher yield of lettuce and significantly reduce nitrate accumulation as compared to the conventional cultivation with chemical fertilizers.

• Journal of Bio-Environment Control
• /
• v.18 no.4
• /
• pp.377-384
• /
• 2009

This study was conducted to examine the effects of electrical conductivity (EC) and rootstock on initial growth and physiological response of grafted pepper in protected cultivation. The pepper (Capcicum annuum L.) cultivars 'Nokgwang' was used as scions, and the cultivars used as rootstocks were Capcicum annuum L: 'Kataguruma', 'Conesian hot' and 'Tantan'. The scion cultivar left ungrafted was used as a control. Two experiments were to examine the effects of the EC levels of nutrient solution on the growth and physiological response of grafted pepper, respectively. Nutrient solution was supplied with three level (1.5, 3.0, 5.0dS/m). By the change of nutrient solution EC level, the plant growth of all seedlings decreased with the increase in EC level. grafted seedling was grafted onto rootstock cultivar 'kataguruma' showed higher growth than the other cultivar at the EC 5.0dS/m level. But this result was slightly different by cultivation time (spring and fall). The total N and P concentration were increased with the increase in EC level, but the Ca and Mg concentration were decreased. Photosynthetic rate of ungrafted seedlings decreased at the EC 5.0dS/m level. But there was no difference between EC 1.5 and 3.0dS/m level. Grafted seedlings showed lower photosynthetic rate at the EC 5.0dS/m level. The activity of SOD do not have a uniformly tendency by the EC level. With the EC 5.0dS/m level, the activity of APX attained higher level than the other EC level. Further study will be needed to examine additional cultivation experiment for more variable rootstock, and development of rootstock for salinity tolerance.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.6
• /
• pp.1058-1064
• /
• 2002

The purpose of this study was to investigate the effects of green tea on hepatic antioxidative defense system and recovery of muscle fatigue in rat after aerobic exercise. Male Sprague-Dawley rats weighing 150$\pm$ 10 g were randomly assigned to one normal (N) group and aerobic exercise training groups. Exercise training groups were classified into two groups: training (T) group and green tea (TG) group which were supplemented the distilled water and green tea extracts by dringking water during experimental periods, respectively. The experimental rats in exercise training groups (T and TG) ran on a treadmill 30 min/day at a speed of 28 m/min (7% incline) 5 days/week or were cage confined (Normal group) for 4 weeks. And rats were sacrificed with an overdose of pentobarbital injection just after running. Hepatic xanthine oxidase (XOD) activities were not significantly different among three groups. The activity of superoxide dismutase (SOD) in T group was no significant difference from N group, but those of TG groups were significantly increased, compared with that of T group. Hepatic glutathione peroxidase (GSHpx) activites of TG groups showed a similar tendency to that of normal group, but it was increased to 20% in TG group, compared with normal group. The reduced glutathione (GSH) contents in liver was not significantly different from that of any three group. The oxidized glutathione (GSSG) contents in T group was increased to 69%, compared with the normal group, but TG group significantly decreased, compared with the T group. The ratio of GSH/GSSG in liver of T group was lower than that of normal group, but those of TG group was a similar tendency to that of normal group. Contents of thiobarbituric acid reactive substance(TBARS) in T group was increased to 52%, compared with that of normal group but those of TG group were recovered the normal level. Contents of hepatic glycogen in T group were decreased to 23% compared with those of normal group, while that of TG group was the same as normal levels. The contents of serum lactic acid in T group were increased to 261%, compared with normal group, but those of TG group maintained the normal level by green tea supplementations. In conclusion, the effects of green tea in exercise training rats would appear to reduce peroxidation of tissue as an antioxidative defense mechanism and promote recovery of muscle fatigue.

• Journal of Aquaculture
• /
• v.21 no.2
• /
• pp.82-88
• /
• 2008

A 12-week feeding trial was conducted to investigate the effects of dietary supplementation of probiotics as a feed additive for juvenile Korean rockfish Sebastes schlegeli. Four experimental diets supplemented with no probiotic(Control), Bacillus polyfermenticus(BP), Bacillus licheniformis(BL) or Bacillus polyfermenticus plus Saccharomyces cerevisiae(BP+SC) at $1.0{\times}10^7$ CFU/kg diet as a dry-mater(DM) basis were prepared by mixing with a basal diet. After 12 weeks of the feeding trial, fish fed BP+SC diet showed significantly higher weight gain(WG), feed efficiency(FE), specific growth rate(SGR) and protein efficiency ratio(PER) than those of fish fed control diet(P<0.05), however there were no significant differences in WG, FE, SGR and PER among fish fed the BP, BL and BP+SC diets. Fish fed BP and BP+SC diets showed significantly higher condition factor(CF) than that of fish fed control and BL diets. Fish fed BP, BL, BP+SC diets showed significantly higher hepatosomatic index(HSI) than that of fish fed control diet, however there was no significant difference in HSI among fish fed BP, BL and BP+SC diets. Fish fed BP+SC diet showed significantly lower serum glucose than that of fish fed control diet, however there was no significant difference in serum glucose among fish fed BP, BL and BP+SC diets. Fish fed BP+SC diet showed significantly higher respiratory burst activity(NBT assay) than that of the fish fed control and BL diets, however there was no significant difference in NBT assay between fish fed BP and BP+SC diets. Fish fed BP and BL diets showed significantly higher lysozyme activity than that of the fish fed control diet, however there was no significant difference in lysozyme activity among fish fed BP, BL and BP+SC diets. Fish fed BP and BP+SC diets showed significantly lower cumulative mortality than that of the fish fed control diet, however there was no significant difference in cumulative mortality among fish fed BP, BL and BP+SC diets after the challenge test. From these results, dietary B. polyfermenticus, B. licheniformis and B. polyfermenticus plus S. cerevisiae supplementation in juvenile Korean rockfish diet could enhance growth performances, non-speicific immunities and a higher resistance against the specific pathogen.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.5
• /
• pp.826-833
• /
• 2002

This study was conducted to investigate the effects of YK-209 mulberry leaves on HMG-CoA reductase activity and lipid composition of liver in streptozotocin-induced diabetic rats. Sprague-Dawley male rats weighing 100 $\pm$ 10 B were randomly assigned as a normal group and four STZ-induced diabetic groups according to the level of dietary mulberry leaves supplement. The experimental diets were fed ad libidum, so that diabetes was experimentally induced by intravenous injection of STZ 55 mg/kg of body weight after feeding for 3 weeks. Animals were sacrificed on the 9th day of diabetic states. The levels of serum triglyceride, total-cholesterol and LDL-cholesterol in DM group were higher than mulberry leaves supplemented groups and normal group, but those of the mulberry leaves supplemented groups were significantly decreased to normal level. In contrast, the leavels of serum HDL-cholesterol in DM group was significantly reduced than that of normal group, but mulberry leaves supplemented groups were increased to normal level. Atherogenic index in DM group was higher about 3 fold than the normal group but the DM-0.1Y and DM-0.2Y groups were maintained the normal level. Contents of total lipid and triglyceride of liver in DM group were significantly lower than that of normal group, but the mulberry Leaves supplemented groups increased than that of DM group. The contents of hepatic cholesterol in DM group was 160% higher than that of normal group, but the mulberry leaves supplementation groups maintained the normal level. The activity of hepatic 3-hydroxy -3-methylglutaryl Coenzyme A (HMG-CoA) reductase in DM group was 43% lower than that of normal group, but had no significant difference between DM-0.1Y, DM-0.2Y and normal groups. In conclusion, YK-209 mulberry loaves has improving effect of the lipid metabolism in STZ-induced diabetic rats through hepatic HMG-CoA reductase activity, and the change of lipids contents in serum and liver.

• The Korean Journal of Ecology
• /
• v.28 no.6
• /
• pp.417-431
• /
• 2005

Soils of Korea experienced with long-term acidic deposition have been exhaustively leached exchangeable base cation (BC) for plant nutrient comparable with soils of forest decline areas in Europe and N. America. Ratios of $BC/Al^{3+}$ of most soils are below than 1, which value is critical load for plant growth. Acid soil applied with dolomitic liming is increased as much as 20% and 244% in concentrations of $Ca^{2+}$ and $Mg^{2+}$, respectively, as well as shrub leaves increase much cation uptake by 1 year later. Ions of $NO_3^-$ and $NH_4^+$ in acid rain are absorbed by the canopy acted as the sink but f is leached out from the canopy to throughfall as the source at Gwangneung forest with a little of acidic deposition, however, such sink and source functions are not found at Kwanaksan forest because of so much deposition. In coniferous and deciduous forested watershed ecosystems ions of $K^+$, $Cl^-$, $NO_3^-$ and $SO_4^{2-}$ from throughfall are retained in forest floor but ions of $Na^+, $Mg^{2+}$ and $Ca^{2+}$ are leached from the floor to streamwater.

• Journal of Wetlands Research
• /
• v.7 no.2
• /
• pp.37-52
• /
• 2005

Vertical distribution of bacterial population and activities were compared between the muddy and sandy sediment of the tidal flat located in southern area of Ganghwa Island. The average of bacterial number and activities in mud flat was slightly higher than that in sand flat. Bacterial number was markedly increased at the sandflat during the investigation period, which seemed to be the result of increase of mud content. The number and activities of microorganisms in mudflat was comparable to that of the mangrove sediments. There was no differences in bacterial number with the depth, but the aminopeptidase activity and bacterial productivity were decreased markedly within 3~5cm depth of sediment due to the availability of carbon sources and molecular oxygen in pore water. The number and activities of microorganisms in mudflat did not correlated with the distribution of benthic microalgae; however, those in sand flat were closely correlated with the distribution of benthic microalgae. The distribution of marsh plant in the mudflat area might be the reason of the difference.

• Applied Biological Chemistry
• /
• v.37 no.3
• /
• pp.182-188
• /
• 1994

Similar to the $^{42}K$ uptake, $^{86}Rb$ uptake by the roots of Hordeum distichum grown in the hydroponic culture was negatively correlated with the concentration of K supplied previously, showing that $^{86}Rb$ can be used for the K-bioassay. $^{86}Rb$ having longer half life (18.86 day) than $^{42}K$ (12.36 hr) allowed the use of larger number of root samples. $^{86}Rb$ uptake of 3 years old Citrus unshiu Marc. grown in water culture decreased drastically with the increase of K concentration of the culture solution, thus demonstrating that the nutrition status of K for citrus trees can be diagnosed by K-bioassay using $^{86}Rb$ tracer. $^{86}Rb$ uptake by the excised roots of Hordeum distichum grown in the pot with different K fertilizations was well correlated with the exchangeable K in soil. The amount of exchangeable K in soil for the optimal plant growth can be determined by its relationship. $^{42}K$ and $^{86}Rb-uptake$ by the Hordeum distichum roots were markedly inhibited by $5{\times}10^{-3}\; M$ KCN in the bioassay solution, indicating that uptake is energy-dependent. There was no significant relationship between K content in citrus leaves and K concentration in the water-culture medium. It is concluded that K-bioassay is a potentially useful tool for determining of K requirement in citrus trees.

• Korean Journal of Soil Science and Fertilizer
• /
• v.20 no.1
• /
• pp.35-41
• /
• 1987

Nitrate nitrogen was absorbed dominantly among the inorganic nitrogen nutrients by tobacco plant. Transport and reduction of $NO_3-N$ in plant tissue were the important metabolism for supplying synthetic N compounds to developing tissues during growth period. Under field and environment-controlled condition tobacco plants were grown and seperated to leaf tissues at stalk positions for investigation of nitrogen transport and assimilation ability during period of rapid vegative growth. The results of studies were summarized as follows: 1. $NO_3-N$ absorbed from roots was transported as inorganic nitrogen through the vascular tissue of leaf veins as resulting from the high $NO_3-N$ ratio of the nitrogen content in leaf veins, but these ratios in mesophyll tissue of the same leaf laminae decreased remarkably in disregard of higher accumulation of nitrogen being compared to midvien. 2. Mesophyll tissue of mature leaves appeared higher value of nitrate reductase activity (NRA) comparing with other tissues, stem, leaf vien, and meristmatic tissue at emergence point with young leaves. 3. Matured leaves at lower position being reducing nitrate nitrogen vigorously observed thick laminae and kept high amount of water in them. 4. Mature leaves of young plant reduced $NO_3-N$ vigorously for supply synthetic N compounds to meristmatic tissues at growing point by the reason of narrow and few leaves at young stage, but in advancing growth period NRA of mature leaves along upper position reached to lower value. This appearence attributed to distribution of organic-N compound demanding for growth to increasing numbers of wide leaves.