• The Korean Journal of Pesticide Science
• /
• v.11 no.4
• /
• pp.254-260
• /
• 2007

In order to evaluate the toxic effects of butachlor, a herbicide widely used for control of weeds in paddy field, on medaka (Oryzias latipes), acute toxicity tests for five developmental stages and early life stage toxicity test of were conducted. As the results of acute toxicity test, $96h-LC_{50}s$ for 1 day, 1 week, 2 weeks, 2 months and 5 months after hatching of O. latipes were 0.68, 0.52, 0.38, 1.09 and $0.45\;mg\;L^{-1}$, respectively. This indicated that the most sensitive stage was 2 weeks after hatching. The early life stage toxicity test showed that no statistically significant hatching period and hatching success of embryo was observed at all concentrations of butaclor. However, 0.05 and $0.1\;mg\;L^{-1}$ of butachlor showed statistically significant post hatching survival with p<0.1. Abnormalities of larva were 2.1, 2.3 and 10% at 0.025, 0.05 and $0.1\;mg\;L^{-1}$ of concentration, respectively. They showed abnormal vertebral axis, craniofacial alteration and retarded yolk-sac resorption. The total length and weight were decreased depending on butachlor concentration the end of test. Weight of larva was showed more sensitive toxic indicator than total length. The toxicological responses of O. latipes to butachlor expressed as LOEC(lowest observed effect concentration), NOEC(no observed effect concentration) and MATC(maximum acceptable toxicant concentration) values were 0.025, 0.013 and $0.018\;mg\;L^{-1}$, respectively.

• Environmental Analysis Health and Toxicology
• /
• v.24 no.4
• /
• pp.321-332
• /
• 2009

본 연구의 목적은 다이아지논(Diazinon; O, O-diethyl O-[6-methyl-2 (1-methylethyl)-4-pyrimidinyl] phosphorothioate)에 노출된 모델 생물체(송사리)의 행동변화와 관련된 분자생물학적 기전 규명을 통하여 비정상적 행동의 모니터링을 위한 생물지표(biomarker)를 개발하는데 있다. 이를 위해 우선 suppression subtractive hybridization (SSH) 및 DNA microarray 기법을 활용하여 다양한 유전자를 스크리닝하였다. 다이아지논에 노출시킨 송사리에서 발현의 차이가 나는 상향 조절된 유전자 97개 (알려지지 않은 유전자 27개 포함)와 하향 조절된 유전자 99개 (알려지지 않은 유전자 60개 포함)를 동정 하였고 이들 중 이상행동과 관련되는 것으로 보이는 유전자 10개 (상향조절 5개, 하향조절 5개)를 선발하였다. 이들 중에서 primer 제작이 잘된 beta-1, Orla C3-1, parvalbumin 및 apolipoprotein E을 선발하여 그 유전자 발현을 real-time PCR 기법을 사용하여 정량적으로 모니터링 하였다. Orla C3-1, parvalbumin 및 apolipoprotein E는 고농도의 다이아지논 처리(1000 ppb; 24 h)에서 그 발현이 억제됨이 관찰되었다. 다이아지논 처리 시 신경질환 (알츠하이머 병 및 다운신드롬)에 관련된 apolipoprotein E와 근육세포의 유연화에 작용하는 parvalbumin 등의 발현억제는 송사리의 인지능력 교란 및 근육세포의 경직 등을 각각 유도하여 송사리의 비정상적 행동을 야기하는 것으로 판단되었다. 따라서 이들 생물지표는 신경독성물질에 의한 송사리 및 기타 어류의 이상행동의 변화의 감지에 활용될 수 있을 것으로 사료된다.

• Environmental Analysis Health and Toxicology
• /
• v.25 no.2
• /
• pp.145-151
• /
• 2010

Perfluorinated chemicals (PFCs) is a kinds of persistent organic pollutants, and have the potential toxicity of which is causing great concern. In this study, we employed Oryzias latipes embryos to investigate the developmental toxicity of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA)s compound using flowthrow system for 14 day. O. latipes embryos were exposed to solvent control, 20, 40 and 80 mg/L of PFOS and 62.5, 130, 260 mg/L of PFOA respectively. After exposure, hatchability, mortality, total length and heart beats were examined. Hatching rates were reduced approximately 27% in the 80 mg/L PFOS-treated group and 17% in the 62.5, 130 mg/L PFOA-treated groups. Heart beats in the PFOS-treated groups were reduced at 7 day but, PFOA-treated groups were increased heart beats. 80 mg/L PFOS treated group showed significant reduction in growth (total length) level to 90% of control. But PFOA did not showed significant effect on growth. In the 14 days $LC_{50}$ of PFOS and PFOA was 22.74 mg/L and 173 mg/L, respectively. The overall results indicated that the early stage of O. latipes might be a reliable model for the testing of developmental toxicity to perfluorinated chemicals.

• Korean Journal of Environmental Agriculture
• /
• v.7 no.2
• /
• pp.117-123
• /
• 1988

This study was initiated to understand the mechanism of selective toxicity of diazinon and carbofuran to killifish and loach. Conventional LC50 was calculated from fish test. IC50 with acetylcholinesterase activity was estimated using whole body and wet brain homogenate of the two fish species. Acetylcholinesterase activity of killifish was approximately twice as high as that of loach. The selective toxicity of diazinon to killifish and loach was partly (14 : 4) explained by the IC50 of diazoxon, a toxic metabolite of diazinon. IC50 of carbofuran also partly (14 : 3.4) contributed to the selectivity. These result suggested that the enzymatic method might be utilized as a screening tool for the chemicals affecting fish species of environmental concern with certain limitations which should be overcome in future studies.

• Journal of Environmental Health Sciences
• /
• v.26 no.3
• /
• pp.25-31
• /
• 2000

In order to assess the accumulation levels of cadmium and other metals(Zn, Cu, Ca and Fe) in fish bodies, an experimental study was performed by raising fry of "Oryzias latipes" in the water containing cadmium 0.03 ppm, cadmium 0.03 ppm + zinc 0.03 ppm and in the tap water(control group) were made. In the results the concentration of Cd in fish bodies were increased with advancing exposure time in Cd 0.03 ppm treated group and 0.03 ppm + Zn 0.03 ppm treated group, but there was no significantly different between both groups with Cd concentration in each week. The concentration of Zn in fish bodies was no changed with advancing exposure time in control group and Cd 0.03 ppm + Zn 0.03 ppm treated group were significantly different from control and Cd 0.03 ppm treated group. The concentration of Cu, Ca and Fe in fish bodies were increased with advancing exposure time, and control group was higher than any other groups. Simple correlation analysis showed that the positive correlation between Cd and Zn, Cu and Ca, Fe, Ca and Fe, but Cd was negative correlation with Cu, Ca and Fe. In conclusion, we investigated a tendency that the concentration of Cd and Zn in fish bodies tended to increase with the lapse of time, but Cu was unchanged and those of Ca and Fe were decreased in administrating the trace dose of Cd and Zn in water. in water.

• Environmental Analysis Health and Toxicology
• /
• v.15 no.3
• /
• pp.61-67
• /
• 2000

Toxic lesions of styrene in the Japanese Medaka (Oryzias latipes) were compared with those of styrene oxide, the active metabolite of styrene, using embryo-larval assays. The developmental stages of Japanese Medaka (Oryzias latipes) treated with both chemicals were not altered and progressed normally. However, styrene oxide was more toxic than styrene in terms of causing death and lesions . High concentrations of styrene (higher than 4.9 ppm) and styrene oxide (higher than 2.4 ppm), resulting in more than 50% mortality, caused similar lesions of cardiovascular system, craniofacial bone formation and spinal deformities, although a number of lesions were not observed by both chemicals . In the group treated with styrene, eyeball sizes and intereye distances were reduced, while, in the group treated with styrene oxide , the eyes and eye cups were not developed and two eyes were sometimes fused. In addition, styrene oxide caused the lesion which involved the posterior brain and brain stem were herniated through the spinal cord . The noticeable difference of toxic symptoms between these two chemicals was the time of onset. Toxicities of cardiovascular system and craniofacial bone formation appeared on day 3 of development in styrene oxide treated group, but, styrene treated group staned to show hemorrhages on day 3 and the craniofacial malformation were appeared on day 5, These differences between two chemicals may be due to the metabolism of styrene to styrene oxide, the reactive intermediate.

• Environmental Analysis Health and Toxicology
• /
• v.23 no.3
• /
• pp.221-230
• /
• 2008

Chlorpyrifos (CPF) is a widely used organophosphate insecticide. Japanese medaka, Oryzias latipes was selected to investigate the effects of chlorpyrifos on survival rate, hatching rate, reproductivity and histopathological changes. Adult fish were exposed to CPF at concentrations of 20, 40, 80 and $160{\mu}g/L$, and the test duration was 4 weeks. An experiment with eggs was also performed under CPF exposure continued for 7 days covering from the fecundation to end-hatching stages. Survival rate of the adult medaka decreased in CPF $80{\mu}g/L$ and $160{\mu}g/L$ treatment groups compared with control, solvent control, $20{\mu}g/L$ or $40{\mu}g/L$L treatment group. Spontaneous start of feeding significantly decreased compared with the control (p < 0.01) when exposed to CPF at above 40 $\mu g/L$. Total spawning decreased by the 20 or $40{\mu}g/L$ CPF treatment compared with the control or solvent control in the test with eggs obtained from untreated adult medaka, and abnormal eggs increased in those CPF-treated groups. There were certain adverse effects at above $40{\mu}g/L$ determined from liver and gonad histological examinations. The results indicate that CPF has insignificant toxic effects in Japanese medaka at less than $20{\mu}g/L$ in long term exposure.

• Korean Journal of Environmental Biology
• /
• v.30 no.4
• /
• pp.314-318
• /
• 2012

The aims of the present study were to estimate the possibility for toxicity test and compare acute toxicity of potassium dichromate in the larva stage of Neocaridina denticulata, Daphnia magna and the juvenile stage of Oryzias latipes. N. denticulate, a freshwater shrimp lives in Korea, is an indigenous species and considered to be useful for toxicity test. D. magna and O. latipes were recommended as a test species for the OECD test guideline. The 96 h-$LC_{50}$ potassium dichromate value was 0.62 mg $L^{-1}$ for the larva stage of N. denticulata and 168.44 mg $L^{-1}$ for the juvenile stage of O. latipes. The 48 h-$EC_{50}$ value was 1.27 mg $L^{-1}$ for the D. magna. The study was confirmed higher sensitivity of the larva stage of N. denticulata to potassium dichromate compared to the D. magna and the juvenile stage of O. latipes.

• Toxicological Research
• /
• v.17 no.2
• /
• pp.139-142
• /
• 2001

Sexual behavior and reproductivity of male fIsh were studied as an in vivo screening method of endocrine disruptors. Male medaka (Oryzias latipes) were exposed to 17$\beta$-estradiol at nominal concentrations of 2 and 20 $\mu\textrm{g}$/l for 14 days. After exposure of the chemical, sexual behavior between male medaka and normal female which were injected with prostaglandin $F_{2\alpha}$ just before the test, was analysed by using video camera for one hour. Normal control male showed courtship dancing such as following, guarding, dancing and crossing while 17$\beta$-estradiol treated male did not show any type oj courtship dancing. Furthermore, fecundity and fertility were significantly decreased in the treated group. It was suggested that analysis of sexual behavior could be a useful endpoint for the screening of the endocrine disruptors.

• Environmental Mutagens and Carcinogens
• /
• v.16 no.1
• /
• pp.30-34
• /
• 1996

This study was performed to examine the availability of using medaka (Oryzias latipes) in teratological test. Medaka embryos were collected within 2 hours post-fertilization and cultured in petri dishes containing buffered saline until hatching. The embryos were treated with 0.56 mg/l chlorpyrifos-methyl and 10 mM methyl methanesulfonate at 20 stages (about 35 hours post-fertilization). Eleven developmental features were selected and observed from 33 stages (about 9 days post-fertilization). Scoring system was developed and applicated for the measurement of potential teratological effects by the test compound. Chlorpyrifos-methyl did not induce teratological effect in medaka embryos. However, we found teratological test using medaka embryo reduced the cost, labors, period and space of experiment significantly compared with teratological study using rodents. Above findings strongly suggest that medaka embryo can be used as a lab animal model for teratogenicity test instead of rodents.