• Animal cells and systems
• /
• 제4권3호
• /
• pp.287-292
• /
• 2000

The present work examined the role of gonadotropin-releasing hormone (GnRH) and dopaminergic drugs on the secretion of maturational gonadotropin (GTH II) in relation to testosterone m treatment. This study provides evidence that the plasma GTH II levels are increased by T treatment in precocious males, but not in the immature animal. In addition, GnRH analogue (GnRHa) alone significantly increased the plasma GTH II secretion in immature rainbow trout treated with T, as well as in T-treated and T-untreated precocious males. However, injection with either dopamine (DA) or domperidone (DOM; DA D2 receptor antagonist) alone did not alter the basal plasma GTH 11 secretion in all experimental groups. The secretion of GTH II in the T-treated precocious males was remarkably influenced by GnRHa or combination of dopaminergic drugs. Notably, the effects of dopaminergic drugs on GnRHa-induced GTH II secretion w8s prolonged by T in precocious males. In T-treated immature animals, GnRHa-induced GTH II secretion was Increased only by a dose DOM (10$\mu$g/g body n) but not by higher dose DOM (100$\mu$/g body wt). In the T-untreated immature rainbow trout, however, plasma GTH 11 secretion was not influenced by the same treatments. Therefore, these results indicate that DA may be acting indirectly by blocking the effect of GnRH on GTH II secretion in vivo. T may act to modulate the relative contribution by the stimulatory (GnRH) and inhibitory (DA) neuroendocrine factors, which would ultimately determine the pattern of GTH II secretion.

• KSBB Journal
• /
• 제15권6호
• /
• pp.658-663
• /
• 2000

호염성 세균에서 추출한 색소를 사료에 일정량 혼합하여 사육시킨 무지개송어의 일반성분 조성 중 수분함량은 사육 4 주 후 77%, 8주 후 73% 내외였다. 조단백질의 함량은 4주 후보다 8주 후가 증가된 양상을 보였다. 조지방의 경우도 8 주 후 약간 증가하는 경향이었다. 그러나 무기질의 함량에는 큰 변화가 없었다. 무지개송어 육 중 카로테노이드 함량은 4 주 후 대조구에서 0.0223 mg/100g인 반면, 8주 후 pink구에 서는 0.1702 mg/100g으로 대조구에 비하여 색소 첨가구에서 의 함량이 높게 나타났다. 세균 색소추출물의 첨가구는 8주 후 0.1256, 0.1382 mg/100g으로, pink구나 우렁행이 껍질 색 소추출물구 0.1702, 0.1514 mg/100g에 비하여 색소함량이 다 소 낮았지만 색소침착올 저해하는 경향은 아니었다. 무지개 송어 육 중 축적되는 색소의 조성은 급이 되는 사료의 조성 에 따라 차이가 있지만 사육 4 및 8주 후 canthaxanthin의 함 량이 가장 높았으며, astaxanthin 챔가구는 zeaxanthin의 함량 이 가장 높았다. 그리고 표피 중의 색소 조성비는 급이 4 및 8주 후 P -carotene의 함량이 가장 높았고, canthaxanthin의 함 량은 낮아 육 및 표피 중의 색소침착은 급이되는 먹이의 카 로테노이드 조성에 따라 달랐으며, 세균 색소추출물의 첨가도 무지개송어 체색개선에 도움이 되는 것으로 나타났다.

• 한국양식학회지
• /
• 제18권2호
• /
• pp.69-75
• /
• 2005

One 30-day feeding trial was conducted to examine the effects of dietary salt on seawater adaptability of rainbow trout (Onchorhynchus mykiss) fed three experimental diets containing 0% (control), 4% and 8% salt. The experimetal period included 30 days of feeding trial in freshwater, 3 days of the step by step seawater acclimation with-out feeding diets, and 21 more days of seawater adaptation period (not with all experimental fish) with feeding the basal diet. Growth rates from triplicate groups were determined fur 30 days of feeding trial. Blood samples were taken at the begining and at the end of feeding trial, and 3 times (on 1st, 4th and 8th day) of the seawater adaptation period. Daily survival rates of duplicate groups from three experimetal treatments were recorded for 21 days of the seawater adaptation period. Total average initial and final fish weight were $149.5{\pm}7.6\;and\;187.1{\pm}7.6g$. Feed efficiency of fish fed diets containing 4% and 8% salt were significantly better than those of fish fed the control diet. Average cumulative survival rates were 72, 80 and 88% from the control, 4% and 8% salt diets, respectively. Pulse rate per minutes decreased with dietary salt level. Serum $Na^+\;and\;Cl^-$ concentrations of fish fed 4% and 8% salt diets were significantly higher than those of fish fed the control diet (P<0.05), however, the concentrations were stabilized after 8 days of seawater adaptation. Serum cortisol, glucose, cholesterol and tryglyceride concentrations, and the osmorality of fish decreased with dietary salt level, these values were significantly lower than those of fish fed the control diet. These results indicated that the dietary supplementation of salt could have advantages for seawater adaptability of rainbow trout.

• 한국어병학회지
• /
• 제36권2호
• /
• pp.415-422
• /
• 2023

In veterinary medicine for mammals, studies are being conducted to confirm the effects of antioxidants using pathological toxicity model studies, and are also used to confirm the effect of mitigating liver or kidney toxicity of specific substances. It was considered necessary to study such a toxicity model for domestic farmed fish, so thioacetamide (TAA), a toxic substance that causes tissue damage by mitochondrial dysfunction, was injected into rainbow trout (Oncorhynchus mykiss), a major farmed freshwater fish species in Korea. The experiment was conducted with 40 rainbow trout (Oncorhynchus mykiss) weighting 53 ± 0.6 g divided into two groups. Thioacetamide(TAA) 300mg/kg of body weight was intraperitoneally injected into rainbow trout and samples were taken 1, 3, 5, 7 days after peritoneal injection. As a result, in serum biochemical analysis, AST levels related to liver function decreased 3 and 5 days after intraperitoneal injection and increased after 7 days, and ALT levels also increased after 7 days. In addition, creatinine related to renal malfunction increased 3 and 5 days after TAA injection. In histopathological analysis, pericholangitis and local lymphocyte infiltration were observed in the liver from 1 day after intraperitoneal injection of TAA, and hepatic parenchymal cell necrosis was also observed from 3 days after intraperitoneal injection. Hyaline droplet in renal tubular epithelial cell was observed from 1 day after TAA injection, and acute tubular damage such as tubular epithelial cell necrosis appeared from 3 days after TAA injection. Accordingly, it is thought that it will be able to contribute to studies that require a toxicity model.

• Fisheries and Aquatic Sciences
• /
• 제4권4호
• /
• pp.180-185
• /
• 2001

Al and Cd-induced inhibition of vitellogenin (VTG) production was examined at the estrogen receptor (ER) level in rainbow trout Oncorhynchus mykiss hepatocytes. The binding of $[^3H]$ $estradiol-17\beta\;(E_2)$ to hepatocytes reached a plateau 3 days after addition of $E_2\;(2\times\;10^{-6} M)$to the medium. The binding activity was linearly reduced with the increased concentrations $(-10^{-5}\;M)$ of 4-hydroxy-tamoxifen (4-OHT) and specific binding linearly increased with the increased doses of $[^3H]\;E_2$, indicating that the radioligand bound to ER. Al $(-10^{-4}\;M)$and Cd $(10^{-6}\;M)$ as well as 4-OHT $(10^{-6}\;M)$ significantly reduced the $[^3H]\;E_2$-binding activity by $30­40\%$, while they completely inhibited VTG production. Al and Cd had no effect on $E_2-human$ $ER\alpha$ binding activity at any concentrations used $(-10^5\;nM\;each)$. These results suggested that Al and Cd inhibited VTG production in part by interfereing with the ER level. Inhibitory effects of these metals on the $E_z-dependent$ upregulation of ER activity are also discussed.

• Fisheries and Aquatic Sciences
• /
• 제4권4호
• /
• pp.186-191
• /
• 2001

Vitellogenin (VTG) and VTG mRNA induction by $estradiol-17\beta\;(E_2)$ were examined in the primary cultures of hepatocyte in the rainbow trout. Hepatocytes were precultured for 2 days, then $E_2$ was added and cultured for another 5 days. Media and hepatocytes were then analyzed by electrophoresis and Northern blotting for VTG and VTG mRNA, respectively. The hepatocytes were formed a few aggregates within 5 days without further spreading to a monolayer. Cell viability and high DNA content were maintained during the incubation. The hepatocyte culture with E2 induced a weak VTG band at a molecular weight of 175kDa on Day 2 after $E_2$ addition. The relative amount of VTG was expressed in percentage of total protein concentrations. VTG was gradually increased as $1.9\%$ on Day 2, $6.3\%$ on Day 4 and $7.3\%$ on Day 5. VTG mRNA band was detected at about 6.6 kb in the culture with $E_2$ at day 1 of culture. The level of VTG mRNA expression linearly increased with time until Day 5 (r=0.97).

• 한국양식학회지
• /
• 제3권2호
• /
• pp.145-153
• /
• 1990

국내에서 양식되고 있는 무지개송어의 유전학적 동정 (genetic stock indentification)의 일환으로 염색체 분석을 실시한 결과 염색체 수 2n=60 및 2n=61의 개체 간 염색체 다형 현상이 발견되었다. Idiogram 분석 결과 이와 같은 염색체 다형 현상은 Robertsonian 전좌에 의해 중부 염색체 (metacentiric chromosome) 1개가 1쌍의 단부 염색체(acrocentric chromosome)로 나누어지기 때문 (Robertosoman fission)이었다. 염색체수 60개 및 61개인 개체의 집단 내 빈도는 각각 $38\%$ 및 $62\%$였으며 염색체 수 61개인 개체들에서는 암컷의 비율이 수컷에 비해 높게 나타났다. 염색체 다형 현상을 보인 친어들로부터 3배체를 유도한 결과 유도된 3배체의 염색체 수 분포는 90, 91, 92 및 93개로 나타났으나 염색체 arm의 수는 모두 156개로 2배체와 동일하게 Robersonian 전좌에 기인한 다형 현상을 나타내었다.

• 한국양식학회지
• /
• 제1권1호
• /
• pp.41-51
• /
• 1988

3배체 무지개 송어의 산업적 유용성을 검토하기 위하여 3배체 유도율, 부화 소요시간, 생존율, 세포의 크기, 성장 및 생식소 형성 등을 조사하였다. 그 결과 $96.5\%$의 3배체가 유도되었으며 부화까지 소요시간은 3배체가 2배체에 비해 약간 빨랐고 생존율은 대조군의 $80.2\%$에 달하였다. 세포의 크기는 장, 단축 모두 대체로 1.2$\~$1.3배정도 3배체가 컸으며 성장은 초기에는 2배체가 약간 빨랐으나 부화후 1년이 지나면 3배체가 대조군보다 성장율이 증가되었다. 조직학적 분석결과 3배체의 경우 성숙기에 도달하여도 생식소가 성숙되지 않았다.

• 한국수산과학회지
• /
• 제42권6호
• /
• pp.721-724
• /
• 2009

Astaxanthin is a valuable pigment source for many aquacultured species, including salmonoids, shrimp, sea bream, and ornamental species. Conjugated linoleic acid (CLA) and ascidian tunic extracts were mixed with the basal diet of rainbow trout to investigate their pigmentation effects. Synthetic Carophyll Pink and natural carotenoids that came from the tunic extracts were incorporated into muscle and skin tissues. The main carotenoids found in muscle after 8 weeks were canthaxanthin in CP12 (13.4%), and CP52 (17.2%), and astaxanthin in CP12 (58.5%), and CP52 (59.2%) in the Carophyll Pink group, while those in skin were canthaxanthin in CP14 (34.5%), and CP54 (29.2%), and astaxanthin in CP14 (32.0%), and CP54 (36.5%) in the ascidian tunic extract group. The total carotenoid content in skin (53.0-69.3 mg/kg) was greater than that in muscle (9.5-13.8 mg/kg).

• Fisheries and Aquatic Sciences
• /
• 제14권2호
• /
• pp.89-92
• /
• 2011

We investigated the antioxidant and cholinesterase inhibitory activities of the aqueous extract of rainbow trout Oncorhynchus mykiss. The antioxidant activity of O. mykiss aqueous extract was determined by in vitro peroxynitrite scavenging activity and reducing power assays. The aqueous extract of O. mykiss showed potent peroxynitrite radical scavenging activity ($IC_{50}=0.12{\pm}0.001\;mg/mL$) and reducing power (absorbance=$0.47{\pm}0.001$) at the concentration of 1 mg/mL. The in vitro cholinesterase inhibitory activity of O. mykiss aqueous extract was examined using spectrophotometric analyses of acetyl- and butyrylcholinesterase. The aqueous extract of O. mykiss showed acetylcholinesterase inhibitory activity ($IC_{50}=1.61{\pm}0.13\;mg/mL$), but did not exhibit inhibitory activity against butyrylcholinesterase. These results suggest that O. mykiss possesses antioxidant and acetylcholinesterase inhibitory activities and provide scientific evidence for the health benefits of O. mykiss aqueous extract.