• Journal of fish pathology
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• v.7 no.1
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• pp.63-70
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• 1994

Nitric oxide(NO) has recently been shown to play an important role on central nervous system(CNS) function in mammals. It is synthesized from L-arginine by the enzyme NO synthase. In this study, we examined this enzyme's existence in CNS of rainbow trout(Oncorhynchus mykiss) and described the forms of microglia. astrocytes. and oligodendrocytes. Two forms of microglia are distributed in CNS. one resembling their mammalian counterpart(large microglia : LM). and the other comprising small microglia(SM) with very little cytoplasm. CNS contained astrocytes of a distinct type which form reticular network, but lack connections to capillaries. The oligodendrocyte was generally a much denser cell than the astrocyte. We have detected NOS($1.04{\pm}0.12\;pg/min/mg$) from rainbow trout CNS. It could be inhibited reversibly or irreversibly by $N^{G}MMA$ and EGTA. These result suggest that the formation of NO from L-arginine in CNS is calcium-dependent and a pathway of early evolutionary orgin.

• Journal of Life Science
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• v.20 no.11
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• pp.1634-1639
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• 2010

This study was conducted to increase the efficiency of farming practice in rainbow trout, Oncorhynchus mykiss, by sex reversal and chromosome-set manipulation techniques. To obtain phenotypic males, hormonal sex reversal was carried out using an exogenous hormone treatment method. 5 mg of 17 alpha-methyltestosterone per kg diet was supplied for 82 days after first feeding at $10^{\circ}C$ and $13^{\circ}C$. More than 93% of the male population was produced by this method and growth of hormone-treated fish at $13^{\circ}C$ was faster than that of untreated bi-sexual groups. Induced diploid gynogenesis was carried out using artificial insemination of UV-irradiated sperm into haploid eggs. Based on the appearance of the rate of haploid syndrome and survival of embryo, a UV ray dose of at least $3,600\;erg/cm^2$ was required to inactivate rainbow trout sperm genetically. Haploid embryos were restored to diploid by blocking the extrusion of the second polar body using heat shock treatment at $28^{\circ}C$ for 20 min, 10 min post insemination. Gynogenetic diploid sex ratios were confirmed after maturation of the fish erythrocyte measurements and chromosome counts.

• Journal of Aquaculture
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• v.16 no.1
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• pp.1-7
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• 2003

A new technique combining forced-feeding and dorsal aorta cannulation was developed to monitor concentration of nutritions in the blood circulation and their metabolites in rainbow trout. To study the effect of dorsal aorta cannulation on stress, 30 rainbow trout (523$\pm$5.4 g; Mean$\pm$SD) were divided into 6 groups of 5 individuals each. A group was anesthetized and blood samples were taken at 0, 3, 6, 12, 24 or 48 h after dorsal aorta cannulation. Hematocrit peaked at 6 h and returned to 0 values by 12 h after dorsal aorta cannulation. Plasma cortisol and glucose concentrations also peaked at 6 h and returned to 0 values by 48 h after dorsal aorta cannulation. Based on the plasma cortisol and glucose concentrations, the rainbow trout recovered from the operation of dorsal aorta cannulation within 48 h. To compare the patterns of plasma free amino acid concentrations after force-feeding in the fish with dorsal aorta cannulation, 5 dorsal aorta cannulated individuals (511$\pm$6.2 g) were kept in a cage. After 48 h starvation, they were anesthetized and blood samples were taken at 0, 4, 8, 12, 24, 36 or 48 h after forced-feeding. The concentration of all plasma free amino acids, except isoleucine, leucine, phenylalanine, and tryptophan, also peaked at 4 h and returned to 0 values by 24 h after feeding. The combined technique allows forced-feeding and repeated sampling of blood in rainbow trout with minimum stress.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.445-453
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• 1994

Rainbow trout, Oncorhynchus mykiss, were cultured with different levels of carotenoids in odor to investigate the feeding effect of ascidian tunic extracts on the liver fatty acid compositions of them. Dominant monoenoic fatty acids of the ascidian tunic extracts were 16:1n-7($5.9\%$), 18:1n-9($21.9\%$), and 18:1n-7($3.5\%$) and polyenoic fatty acids of them were linoleic(18:2n-6, $14.2\%$), eicosapentaenoic(20:5n-3, $3.5\%$), and docosahexaenoic acid(22:6n-3, $8.3\%$). The compositions of fatty acid in the liver lipids were affected by the tunic extract levels during the feeding. The percentage of monoenoic acids in extract diets was decreased, and that of n-3PUFA was increased during feeding 2 weeks. But the n-3PUFA contents were decreased in 4 weeks. The 20:4n-6 content in rainbow trout fed extract diet was higher than that in the control and pink diet groups. The rainbow trout fed with ascidian tunic extracts showed an increase of essential fatty acids in the fish tissue, compared to the control or pink diet feeding groups.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.231-232
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• 2000

자치어의 소화생리에 대한 연구는 담수어인 잉어, 무지개송어 등과 해산어인 넙치, 혹돔 등의 연구가 있으나 자치어 단계에 서식지의 변화가 큰 어종에 대한 연구는 전무한 실정이다. 따라서, 본 연구는 담수생활의 자어기에서 해수생활의 치어기로 전환하는 황복의 초기단계에 소화효소의 변화과정을 밝히고, 온도ㆍ염분ㆍ빛 등의 환경요인과 소화효소와의 관계를 조사하고자 한다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.318-319
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• 2000

양식어류의 소비증가와 더불어, 양식 생산성을 증대시키기 위하여 어류의 성장촉진을 위한 연구가 다양하게 이루어지고 있다. 그 중에서 성장 호르몬을 이용한 연구에서 어류의 성장 촉진효과가 일찍부터 알려져 왔다. 국내에서도 유전자 재조합 bST가 대량생산이 가능하게 되었으며, 넙치, 무지개 송어, 잉어, 뱀장어, 조피볼락에서 성장촉진 효과가 있다고, 보고하였다(LG 보고서, 1996;옥등, 1999). (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.299-300
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• 2001

어류에 있어 사료섭취를 촉진하는 물질은 분자량이 1,000 미만인 수용성 물질로서 이온 흡착 기능을 가진 성분으로 알려져 있으며(Carr et al., 1982), Adron and Mackie(1978)은 무지개 송어에 대한 오징어 추출물의 주요 자극 물질은 아미노산 혼합물로서, 대부분 은형의 아미노산이 자극제로 작용한다고 보고하였다. 또한, 섭취촉진 물질의 종류에 있어서는 대부분 염기성 아미노산, 인지질 및 몇가지 핵산 관련물질을 미꾸리, 전복, 방어에 대하여 사료섭취촉진 효과를 가지는 것으로 알려져 있다(Harada and Ikeda, 1984; Harada, 1985). (중략)

• KOREAN POULTRY JOURNAL
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• v.49 no.12
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• pp.118-120
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• 2017

지난 10월 24일 대전 소재 선샤인호텔에서 '2017년 제4차 계란자조금관리위원회 대의원회'를 통해 제5대 계란자조금관리위원장에 남기훈 후보가 만장일치로 추대됐다. 더불어 이날 자리에서 대의원회 의장에 오정길 씨(전, 한국양계축산업 협동조합장), 부의장은 김양길 씨(본회 광주전남도지회장), 감사에는 한만혁 씨(무지개농장)와 장재권 씨(자연농장)가 당선됐다. 금년 초 본회 제21대 임원으로 선출되면서 본회 부회장이자 채란위원장에 이어, 2년간 계란자조금관리위원회를 이끌어갈 남기훈 위원장을 만나 앞으로 운영 계획에 대해 들어보았다.

• Journal of fish pathology
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• v.23 no.1
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• pp.1-8
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• 2010

Infectious hematopoietic necrosis virus (IHNV) is the causative agent of IHN, one of the most serious viral diseases of salmonid fish. In this study, glycoprotein (G) gene nucleotide sequence of isolated IHNV RtWanju09 from Jeollabuk-do province was analyzed to evaluate their genetic relatedness to worldwide isolates. As the result, it was revealed that IHNV RtWanju09 isolate belongs to JRt Shizuoka lineage with IHNV RtPy91 and RtJe00. The genetic diversity of G gene between RtWanju09 isolate and RtPy91 isolate from Gangwon-do province was 1.77% and maximum nucleotide diversity among the JRt Shizuoka lineage in Korea was 3.03% during the past 20 years, supporting that the continuous evolution has been occurred among JRt Shizuoka isolates. It was believed that IHNV RtWanju09 isolate has been introduced by the movement of contaminated eggs with IHNV from Gangwon-do to Jeollabuk-do by the reason that the eyed eggs in Jeollabuk-do province used to be obtained from Gangwon-do province. In this study, the domestic transfer of IHNV was firstly investigated by the transfer history of eggs and the phylogenetic analysis using IHNV glycoprotein gene sequence.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.4
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• pp.469-474
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• 1995

The effects of sperific inhibitors of $3\beta-hydroxy-\Delta^5-steroid\;dehydrogenase$ $(3\beta-HSD;\;an\;enzyme\;catalyzing\;conversion\;of \Delta^5\;steroids\;to\;\Delta^4 steroids),$ cyanoketone and trilostane, on $^3H-pregnenolone$ metabolism in isolated ovarian thecal layers have been investigated in vitro. At all doses of cyanoketone $(10^{-5}\;and\;10^{-4}\;M)$ and trilostane $(10^{-5}\;and\;10^{-4}\;M)$ $(3\beta-HSD$ enzyme activity that transforms pregnenolone to $17\alpha-hydroxyprogesterone$ was inhibited in the thecal layers. Trilostane appeared to be more efficient than cyanoketone. Trilostane at doses of $10^{-8},\;10^{-7},\;10^{-6},\;and\;10^{-5},\;M/ml$ caused a dose-response inhibition of $\Delta^4$ steroids accumulation in the medium from pregnenolone, but not completely blocked the conversion of $\Delta^5\;to\;\Delta^4$ steroids.