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Bisphenol A가 흰쥐의 태반 기능과 출산에 미치는 영향
이채관,김석현,문덕환,김정호,손병철,김대환,이창희,김휘동,김정원,김종은,이채언,Lee, Chae-Kwan,Kim, Seog-Hyun,Moon, Deog-Hwan,Kim, Jeong-Ho,Son, Byung-Chul,Kim, Dae-Hwan,Lee, Chang-Hee,Kim, Hwi-Dong,Kim, Jung-Won,Kim, Jong-Eun,Lee, Chae 대한예방의학회 2005 예방의학회지 Vol.38 No.3
Objectives : The aim of this study was to investigate the effects of bisphenol A (BPA), an estrogen-like environmental endocrine disrupter, on the placental function and reproduction in rats. The mRNA levels of the placental prolactin-growth hormone(PRL-GH) gene family, placental trophoblast cell frequency and reproductive data were analyzed. Methods : The pregnancies of F344 Fisher rats ($160g{\pm}20g$) were detected by the presence of the copulatory plug or sperm in the vaginal smear, which marked Day 0 of pregnancy. Pregnant rats were divided into three groups. The control group was intraperitoneally injected with a sesame oil vehicle. The two remaining groups were injected with 50 or 500 mg/kg B.W/day of BPA, resuspended in sesame oil, on either days 7 to 11 or 16 to 20 of pregnancy, with the rats sacrificed on either day 11 or 20, respectively. The mRNA levels of PRL-GH and Pit-1a and b isotype genes were analyzed by Northern blot hybridization and reverse transcription-polymerase chain reaction. The hormone concentrations were analyzed by radioimmunoassay, and the frequency of the placental trophoblast cells observed by a histochemical study. Reproductive data, such as the placental weight and litter size, were surveyed on day 20. The fetal weight was surveyed for 4 weeks after birth. A statistical analysis was carried out using the SAS program (version 8.1). Results : The mRNA levels of the PRL-GH gene family, such as placental lactogen I, Iv and II, prolactin like protein A, C and Cv, and decidual prolactin-related protein were significantly reduced due to BPA exposure. The mRNA levels of the Pit-1a and b isotype genes, which induce the expression of the PRL-GH gene family in the rat placenta, were also reduced due to BPA exposure. The PL-Iv and PL-II concentrations were reduced in the BPA exposed group. During the middle to last stage of pregnancy (Days 11-20), a high dose of BPA exposure reduced the frequency of spongiotrophoblast cells, which are responsible for the secretion of the PRL-GH hormones. Reproductive data, such as the placental and fetal weights and the litter size, were reduced, but that of the pregnancy period was extended in the BPA exposed compared to the control group. Conclusions : BPA disrupts the placental functions in rats, which leads to reproductive disorders.
메틸수은 노출이 흰쥐의 태반 효율과 태아 성장에 미치는 영향
이채관(Chae Kwan Lee) 한국환경보건학회 2020 한국환경보건학회지 Vol.46 No.4
Objectives: Some animal studies have reported that methyl mercury causes developmental toxicities such as placental and fetal weight loss, but the mechanism is still unclear. This study aimed to investigate the developmental toxicities of methyl mercury, focusing on placental endocrine function and fetal growth retardation in rats. Methods: Positively same-time-mated female Sprague-Dawley rats were purchased on gestational day (GD) eight and treated with 0, 5, 10 and 20 ppm of methyl mercury (n=5) dissolved in tap water from GD eight through 19. During treatment, the drinking water (methyl mercury) intake and body weight of each pregnant rat was measured daily. On day 19, caesarean sections were performed and blood samples were collected. Developmental data such as placental and fetal weights, fetus numbers, and placental efficiency (fetal weight/ placental weight) were also collected. Placental prolactin-growth hormone (PRL-GH) family, such as placental lactogen (PL) -Iv, II, and prolactin-like protein (PLP) -B, levels in serum were analyzed by ELISA. Also, placental tissues were assigned to histochemistry. Results: The mean cumulative methyl mercury exposure for the 5, 10, and 20 ppm groups were 2.37, 4.63, and 9.66 mg, respectively. The mean daily exposure of the 5, 10, and 20 ppm groups were 0.24, 0.47, and 0.97 mg, respectively. Maternal body weight increased in accordance with GD. There was no significant difference in weight gain among the experimental groups. Histopathologic changes were not observed in placental tissues among the experimental groups. However, mean placental and fetal weights were lower in the 10 and 20 ppm exposed groups compared to the control. Placental efficiency was also lower in the 10 and 20 ppm exposed groups compared to the control. Serum PL-Iv and II levels were lower in the 10 and 20 ppm exposed groups than the control, in accordance with the changing pattern of placental and fetal weights and placental efficiency. Conclusion: The inhibitory effects of methyl mercury on the serum levels of placental PRL-GH family such as PL-Iv and II may be secondary leads to the reduction of placental efficiency and fetal growth retardation in rats.
소리의 종류와 크기에 따른 일과성 청력 역치 상승과 회복의 차이
이채관 ( Chae Kwan Lee ) 한국산업보건학회 (구 한국산업위생학회) 2020 한국산업보건학회지 Vol.30 No.4
Objective: This study aimed to investigate the differences in temporary threshold shift (TTS) and recovery patterns according to different types of sound and volume. Methods: TTS and recovery patterns were assessed for eight students after 30-minute exposure to both 70.0 dB and 90.0 dB of factory noise (noise) as well as music. TTS was measured before exposure and two minutes post exposure, and recovery patterns were evaluated every 10 minutes for one hour. The subjects performed activities of daily life and sleeping times as usual but taking drugs or drinking alcohol were prohibited. The experiment was repeated three times with an interval of at least 16 hours. ANOVA and T-test were carried out using SPSS 19.0 for Windows. Results: The hearing threshold of all subjects before exposure was less than 30 dB at all frequencies. Mean TTSs of 70 dB noise and 90 dB noise exposure were 0.14 and 4.48 dB (p<0.001). Meanwhile, the difference in music was insignificant (-0.63 dB and 0.55 dB, p=0.063). A significance in the difference was also found between the mean TTS of music and noise exposure, more obviously at 90.0 dB (p<0.001) than at 70 dB (p=0.232). The TTS differences were found frequency-wise in terms of sound type. Mean TTS by frequency was higher at 4,000 and 6,000 Hz than at other frequencies, and higher in noise than music at the same sound pressure. The TTS difference in each frequency between both sound types was significant at 90 dB (p<0.001). Subjects mostly recovered from TTS in one hour after exposure, but not with 90 dB-noise exposure. Conclusion: TTS and recovery patterns were different depending on the sound type. When exposed to factory noise, TTS was greater and recovery time was longer compared to music at the same sound pressure. These results suggested that the difference in cognitive processes and psychological factors according to the type of sound causes a change in TTS and recovery.
이채관(Chae Kwan Lee) 한국실내환경학회 2010 한국실내환경학회지 Vol.7 No.1
This study aimed at investigating the gene expression profile in basal ganglia of hexa-valence chromium exposed rat based on cDNA array analysis. For cDNA array, Sprague-Dawley male rats (300 ± 25 g) were administrated with 15 mg/kg BW/day of potassium dichromate by gavage (0.3 mIl dissolved in saline for 10 days (n=5). For dose-related gene expression analysis. rats were administrated with 0, 1, 5 mg/kg BW/day of potassium dichromate for 10 days. Control rats were administrated with equal volume of saline (n=5). For cDNA array analysis, RNA samples were extracted from brain tissue and reverse-transcribed in the presence of ( α32pJ-dATP. Membrane sets of the Atlas array II and Toxicology array kits were hybridized with cDNA probe sets. RT-PCR and Northern blot hybridization methods were employed for validation and assessment of the dose-related gene expression profile, respectively. Arnong the 2352 cDNAs, 43 genes showed significant (>two-fold) changes in expression. 22 genes were up-regulated and 21 genes were down-regulated in the 15 mg/kg BW/day hexa-valence chromium treated group than control. According to the Northern blot hybridization analysis, heat shock protein 47, neurodegeneration associated protein 1 and pituitary specific growth factor 1a genes were up-regulated, but Gamma-aminobutyl-acid a1 subunit, neuroligin2, brain calcium-transporting plasma membrane type ATPase genes were down-regulated even in the low-dose of hexa-valence chromium exposed group (1 mg/kg BW/day) than control. Genes that detected in this study may be closely related to the hexa-valence chromium-induced neurotoxicity in the rat basal ganglia and addition study of these genes can give some more useful information about the neuro-toxic mechanism by hexa-valence chromium.
한국인의 중금속과 유기용제에 대한 인식도와 정보취득 경로
이채관 ( Chae Kwan Lee ) 한국산업보건학회 (구 한국산업위생학회) 2021 한국산업보건학회지 Vol.31 No.1
Objectives: This study aimed to investigate the public cognition and information acquisition route for heavy metals and organic solvents in the general population in order to provide information for the development of public relations materials. Methods: The study was carried out by questionnaire from January to March 2011 by an interview with trained surveyors. There were 700 participants, divided by gender and age. A questionnaire was issued consisting of subjective and objective cognition evaluation items and questions about information acquisition route and preferred information acquisition route for six heavy metals and five organic solvents. Data were expressed as a percentage using the SPSS 23.0 software package. Result: For heavy metals, subjective and objective cognition degrees were higher in the order of lead, mercury, cadmium, and arsenic. They were higher among males than females, and in adults compared to school-age subjects. For organic solvents, both cognition degrees were high in the order of acetone, benzene, and formaldehyde. However, cognition degree by gender and age showed a complex pattern. As a response to information acquisition route, broadcast media had the highest in all ages and genders, followed by word of mouth from neighbors in elementary school children, school education or expert lectures in middle and high school students up to people in their 30s, and print media among those in their 40s to over 60s. There was no difference in the order by gender. As a response to preference for information acquisition route, broadcast media also proved the highest in all ages and genders, followed by school education or professional lectures among those in elementary school and over their 60s, and the internet in other age groups. Females preferred school education or expert lectures and word of mouth from neighbors, while males preferred the internet. In the case of the internet, the ranking was higher for preferred information acquisition route compared with the ranking for information acquisition route. Conclusions: This data on cognition degree, information acquisition route, and preferred information acquisition route according to gender and age can provide basic data for the development of educational and promotional materials for heavy metals and organic solvents exposure management.