• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.57-69
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• 2003

It is well known that many pesticides possess hormonal activity, and affect the developments of wildlife and mammals including human. Currently, pyrethroid insecticides are in worldwide use to control in and outdoor pests, providing potential far environmental exposure. Hormonal activities of these pyrethroid insecticides, however, have been little studied, and the developmental effects of them were no reported. Therefore, we firstly examined the potential estrogenic activities of some pyrethroid insecticides (permethrin, cypermethrin, tetramethrin, deltamethrin, sumithrin, fenvalerate and bioallethrin) by immature rat uterotrophic assay, luciferase reporter gene assay and Calbindin-D$\sub$9k/ (CaBP-9k) gene expression assay. Uterine wet weights were increased by permethrin and the permethrin-induced weights were inhibited by ICI 182780 in the uterolrophic assay. On the other hand tetramethrin significantly reduced uterine and vaginal wet weights, and also inhibited the E2-induced weight increases at all doses tested. Cypermethrin and sumithrin had a tendency to increase uterine weights, although not statistically significant. Permethrin and cypermethrin dose-dependently increased the luciferase activity in reporter gene assay. Northern blot analysis showed that permethrin induced CaBP-9k mRNA expression whereas tetramethrin inhibted. Subsequent studies were conducted to investigate the possible developmental effects of four pyrethroid insecricides (permethrin, cypermethrin, sumithrin and teramethrin). Either diethlbestrol (DES) or 17${\beta}$ -estradiol (E2) was used as a reference control in this study. Pyrethroid insecticides were administered to Sprague Dawley rats via subcutaneous injection at 6 to 18 days of gestation or 1 to 5 days after birth. In utero treatment of permethrin (10mg/kg/day) in female rat resulted in significant increases in uterine and ovarian weights while significant decreases in serum E2 concentration, uterine and ovarian ER${\alpha}$ mRNA levels. Sumithrin and permethrin led to acceleration in vaginal opening of female rat, while delay in preputial separation of male after neonatal treatment. Anogenital distances of PND 18 were significantly reduced in sumthrin-treated, and permerhrin-treated male rats after neonatal treatment. All the pyrethroid insecticides tested caused significant increases in uterine weights on PND 18, while significant reductions in the first diestrus phase when neonataly treated. In addition, exposure to pyrethroids in neonatal period led to significant reduction in relative brain weight in female rat on PND 18, but its weight was recovered in diestrus phase. In summary, Our experimental data demonstrate the possibilities of developmental effects of pyrethroid insecticides via estrogenic or antiestrogenic activity.

• Clinical and Experimental Pediatrics
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• 제46권10호
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• pp.989-995
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• 2003

목 적 : 미숙아들은 심혈관계 및 호흡기계의 미숙으로 만삭아 보다 주산기 저산소증의 발생 가능성이 높으며 만성 폐질환의 예방과 치료를 위한 출생 후 코르티코스테로이드 제제의 투여 기회 또한 높다. 저산소-허혈 즉 주산기 가사가 일어나는 경우 비가역적 손상을 나타내는 기관은 뇌가 유일하므로 뇌손상 정도는 장기적 예후와 직결된다. 이에 저자들은 저산소-허혈에 의한 뇌손상에서 코르티코스테로이드 제제 중 신생아에게 가장 빈번하게 쓰이고 있는 덱사메타손이 신생아 뇌손상에 어떠한 영향을 미치는지를 조사하기 위해 이 연구를 시행하였다. 방 법: 본 연구에는 10마리의 Sprague-Dawley rat 어미에서 태어난 103마리의 신생쥐를 총경동맥 절단과 산소 농도 8%에 노출시켜 저산소-허혈 모형을 만들고 덱사메타손체중 kg 당 0.5 mg을 투여하였다. 적출뇌는 terminal-deoxynucleotidyl-transferase-mediated deoxyuridine triphosphate nick end labelling(TUNEL) 염색, Bcl-2 및 Bax 형광염색, TUNEL 및 synaptophysin 이중 염색을 시행하여 세포 자멸사 양상을 관찰하고 경색부위 면적은 백분율로 구하여 대조군과 비교하였다. 결 과 : 허혈-저산소 환경 노출 후 생존한 95마리 중 덱사메타손 투여군은 54마리, 대조군은 41마리였다. 양육 중 덱사메타손 투여군 가운데 25마리가 사망하였고 대조군은 7마리가 사망하여 덱사메타손 투여군에서의 사망률이 의의 있게 높았다(46.3% vs. 17.1%, P=0.002). 생후 7일째 저산소-허혈 및 투약 전 체중은 두 군에서 차이를 보이지 않았으나 생후 14일째 측정한 체중은 덱사메타손 투여군의 체중 증가가 유의하게 적었다(P=0.001). Bax 및 Bcl-2, Bax/Bcl-2 및 TUNEL 염색 소견은 측정 단위당 Bax가 덱사메타손 투여시 유의하게 증가되었고 Bax/Bcl-2 및 TUNEL 양성세포 역시 덱사메타손군에서 다소 높은 것으로 나타났으나 통계적 유의성은 없었다. 덱사메타손군의 뇌손상 부위는 대조군과 의미 있는 차이를 보이지 않았다. 결 론: 저산소-허혈 후 덱사메타손 투여는 체중 증가 방해, 사망률 증가 등 전신 상태의 악화를 초래하며 뇌세포 자멸사를 조장할 가능성이 있다.

• Journal of Nutrition and Health
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• 제17권3호
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• pp.199-209
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• 1984

Pregnant rats were fed a pyridoxine deficient diet during the gestation and lactation. DEF I group received the deficient diet from delivery ; DEF II group, from the 15 th day of gestation. Body and brain weights, brain protein, DNA, RNA, plasma GOT and GPT, and catecholamines were measured. Effect of MAO inhibiting drug, pargyline, was determined. Brain protein, DNA, and RNA of offsprings of deficient groups were significantly lower than the control group, but RNA/ DNA, brain weight/DNA, and protein/DNA show that cell number were more affected than cell size by the pyridoxine deficiency during the 3rd week of gestation and lactation. Plasma GOT activities were more significantly different than plasma GPT between the control and deficient group. Brain norepinephrine of offsprings of deficient group were significantly lower than the control, but brain dopamine content was not significantly different from the control. At 2nd and 3rd week, norepinephrine was significantly depressed in deficient groups. Pargyline treatment affected a 1.2 fold increase in catecholamines in 3hr while the control had a 1.5 fold increase. Thus norepinephrine and dopamine synthesis was depressed in the deficient groups. Dopaminergic neurons may be less dependent on pyridoxine level than neurons from norepinephrine. Pyridoxine deficiency in maternal diet is not so critical to brain catecholamines of offspring except to the neonatal rats.

• Neonatal Medicine
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• 제15권1호
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• pp.32-37
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• 2008

목 적 : 신생아 질식은 신생아 사망과 영구적 신경발달 장애의 중요한 원인이다. 이에 대한 여러 치료 방법이 시도되어 왔으나 현재까지 임상에 적용 가능한 치료 혹은 예방법은 개발되지 못하고 있다. 산모의 고열은 신생뇌에 악영향을 미치는 것으로 알려져 왔으나 최근 동물에서 시행한 고온 전처치가 뇌손상을 예방한다는 상반된 효과가 보고된 바 있다. 이에 저자들은 신생 동물의 저산소 허혈 뇌손상에 있어서의 고온 전처치의 효과를 조사하고자 이 연구를 시행하였다. 방 법 : 신생쥐를 사용하여 생후 6일에 이들을 두 군으로 나누어 전처지군은 $40^{\circ}C$의 고온 환경에, 대조군은 상온에 2시간 노출시켰다. 24시간 후 두 군 모두 편측 온목동맥 결찰 후 산소 농도 8%의 저산소 환경에 2시간 노출시켜 저산소 허혈을 유도하였으며 저산소 허혈후 7일에 뇌를 적출하여 뇌손상 정도를 비교하였다. 결 과 : 고온 전처치군 16례 중 5례(31.2%)에서 뇌손상이 관찰되어 대조군(17례 중 11례, 64.7%)에 비해 유의성 있게 뇌손상 빈도가 낮았다(P<0.05). 뇌피질, 해마, striatum 및 시상에서 관찰한 손상 부위의 분포 양상과 손상 정도는 전처치군과 대조군 사이에 통계적으로 유의한 차이를 보이지 않았다. 결 론 : 신생쥐에 있어서 2시간의 고온 전처치는 저산소 허혈 뇌손상의 빈도를 감소시켰다. 이는 산모의 발열이 저산소 허혈 뇌손상 보호 효과를 나타낼 가능성을 시사하나 임상 적용에 앞서 다양한 환경 온도 및 장시간의 노출 시간으로 그 효과와 안정성에 대한 연구가 계속되어야 할 것으로 생각된다.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2004년도 International Conference Global Environmental Problems and their Health Consequences
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• pp.185-187
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• 2004

The co-administration of BPA and BBP induced slow weight gain compared with single administration in dams. Also, such mixture induced low neonatal body weights in next generation. The dams treated with BPA and BBP showed significant organ weight changes in liver, spleen exposed during lactational periods. But the dams exposed during lactational periods showed significant organ weight changes not only in liver, spleen but also in kidney, uterus and ovary. The F1 female rats exposed during lactation periods showed significant organ weight changes in liver, spleen, ovary. The F1 male rats showed significant organ weight changes in liver, kidney, epididymis, vesicular glands, prostate. However no clear synergistic effects of BPA and BBP could be found. Estrogen receptor ${\alpha}$ expression by BPA and BBP in the uterus(dam, F1 female) and testis(F1 male) were studied. There was no significant different $ER{\alpha}$ expression pattern between control and treated groups. But $ER{\alpha}$ expression were increased in F1 male testis and female uterus. F1 male showed distinct $ER{\alpha}$ expression, especially in the group of lactational combined exposure. Synergistic $ER{\alpha}$ expression was found by combined treatment of BPA and BBP.

• Nutrition Research and Practice
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• 제9권6호
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• pp.613-618
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• 2015

BACKGROUND/OBJECTIVES: Iron deficiency in early life is associated with developmental problems, which may persist until later in life. The question of whether iron repletion after developmental iron deficiency could restore iron homeostasis is not well characterized. In the present study, we investigated the changes of iron transporters after iron depletion during the gestational-neonatal period and iron repletion during the post-weaning period. MATERIALS/METHODS: Pregnant rats were provided iron-deficient (< 6 ppm Fe) or control (36 ppm Fe) diets from gestational day 2. At weaning, pups from iron-deficient dams were fed either iron-deficient (ID group) or control (IDR group) diets for 4 week. Pups from control dams were continued to be fed with the control diet throughout the study period (CON). RESULTS: Compared to the CON, ID rats had significantly lower hemoglobin and hematocrits in the blood and significantly lower tissue iron in the liver and spleen. Hepatic hepcidin and BMP6 mRNA levels were also strongly down-regulated in the ID group. Developmental iron deficiency significantly increased iron transporters divalent metal transporter 1 (DMT1) and ferroportin (FPN) in the duodenum, but decreased DMT1 in the liver. Dietary iron repletion restored the levels of hemoglobin and hematocrit to a normal range, but the tissue iron levels and hepatic hepcidin mRNA levels were significantly lower than those in the CON group. Both FPN and DMT1 protein levels in the liver and in the duodenum were not different between the IDR and the CON. By contrast, DMT1 in the spleen was significantly lower in the IDR, compared to the CON. The splenic FPN was also decreased in the IDR more than in the CON, although the difference did not reach statistical significance. CONCLUSIONS: Our findings demonstrate that iron transporter proteins in the duodenum, liver and spleen are differentially regulated during developmental iron deficiency. Also, post-weaning iron repletion efficiently restores iron transporters in the duodenum and the liver but not in the spleen, which suggests that early-life iron deficiency may cause long term abnormalities in iron recycling from the spleen.

• The Korean Journal of Physiology and Pharmacology
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• 제7권2호
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• pp.59-63
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• 2003

The medial vestibular nucleus (MVN) neurons are controlled by excitatory synaptic transmission from the vestibular afferent and commissural projections, and by inhibitory transmission from interneurons. Spontaneous synaptic currents of MVN neurons were studied using whole cell patch clamp recording in slices prepared from 13- to 17-day-old rats. The spontaneous inhibitory postsynaptic currents (sIPSCs) were significantly reduced by the $GABA_A$ antagonist bicuculline ($20{\mu}M$), but were not affected by the glycine antagonist strychnine ($1{\mu}M$). The frequency, amplitude, and decay time constant of sIPSCs were $4.3{\pm}0.9$ Hz, $18.1{\pm}2.0$ pA, and $8.9{\pm}0.4$ ms, respectively. Spontaneous excitatory postsynaptic currents (sEPSCs) were mediated by non-NMDA and NMDA receptors. The specific AMPA receptor antagonist GYKI-52466 ($50{\mu}M$) completely blocked the non-NMDA mediated sEPSCs, indicating that they are mediated by an AMPA-preferring receptor. The AMPA mediated sEPSCs were characterized by low frequency ($1.5{\pm}0.4$ Hz), small amplitude ($13.9{\pm}1.9$ pA), and rapid decay kinetics ($2.8{\pm}0.2$ ms). The majority (15/21) displayed linear I-V relationships, suggesting the presence of GluR2-containing AMPA receptors. Only 35% of recorded MVN neurons showed NMDA mediated currents, which were characterized by small amplitude and low frequency. These results suggest that the MVN neurons receive excitatory inputs mediated by AMPA, but not kainate, and NMDA receptors, and inhibitory transmission mediated by $GABA_A$ receptors in neonatal rats.

• 한국전문물리치료학회지
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• 제16권2호
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• pp.50-58
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• 2009

The purpose of this study was to test that motor skill training enhance motor function and cerebellar development. Using an animal model of fetal alcohol syndrome-which equates peak blood alcohol concentrations across developmental period-critifical periods for the effect of alcohol on body and cerebellar weigh was examined. The effect of motor skill training on motor function and cerebellar development of rat exposed alcohol on postnatal days 4 through 10 were studied. Newborn rats were assigned to one of two groups: (1) Control group (CG), via artificial rearing to milk formula and (2) experimental groups (EG), via 4.5g/kg/day of ethanol in a milk solution. After completion of the treatments, the pups were fostered back to lactating dams, and wearing they were raised in standard caged until they were postnatal 48 days. Rats from experimental group of postnatal treatment then spent 10 days in one of two groups: Experimental group II (EGII) was had got motor skill training (training traverse a set of 6 elevated obstacles) for 4 weeks. Experimental group I (EGI) was not trained. Before sacrificing, the rat got examined two behavioral test, body weigh and cerebellar weigh, then coronal sections were processed. The section was investigated the Purkije cell in the cerebellum using light microscope. The results of this study were as follows. 1. In body weight test, the outcome of alcohol groups were significantly lower than the normal group. 2. In cerebellar weight test, the outcome of EGI were significantly lower than CG and EGII. 3. In motor behavioral test, the outcome of EGI was significantly lower than NG and EGII. 4. In Purkinje cells counting test, the outcome of EGI was significantly lower than the NG and EGII. These result suggest that improved motor function induced by motor skill training after postnatal exposure is associated with dynamically altered expression of Purkinje cells and that is related with cerebellar function. Also, these data can potentially serve as a model for therapeutic intervention.

• The Korean Journal of Physiology and Pharmacology
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• 제21권6호
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• pp.579-589
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• 2017

Anesthetics are used extensively in surgeries and related procedures to prevent pain. However, there is some concern regarding neuronal degeneration and cognitive deficits arising from regular anesthetic exposure. Recent studies have indicated that brain-derived neurotrophic factor (BDNF) and cyclic AMP response element-binding protein (CREB) are involved in learning and memory processes. Genistein, a plant-derived isoflavone, has been shown to exhibit neuroprotective effects. The present study was performed to examine the protective effect of genistein against isoflurane-induced neurotoxicity in rats. Neonatal rats were exposed to isoflurane (0.75%, 6 hours) on postnatal day 7 (P7). Separate groups of rat pups were orally administered genistein at doses of 20, 40, or 80 mg/kg body weight from P3 to P15 and then exposed to isoflurane anesthesia on P7. Neuronal apoptosis was detected by TUNEL assay and FluoroJade B staining following isoflurane exposure. Genistein significantly reduced apoptosis in the hippocampus, reduced the expression of proapoptotic factors (Bad, Bax, and cleaved caspase-3), and increased the expression of Bcl-2 and Bcl-xL. RT-PCR analysis revealed enhanced BDNF and TrkB mRNA levels. Genistein effectively upregulated cAMP levels and phosphorylation of CREB and TrkB, leading to activation of cAMP/CREB-BDNF-TrkB signaling. PI3K/Akt signaling was also significantly activated. Genistein administration improved general behavior and enhanced learning and memory in the rats. These observations suggest that genistein exerts neuroprotective effects by suppressing isoflurane-induced neuronal apoptosis and by activating cAMP/CREB-BDNF-TrkB-PI3/Akt signaling.

• 대한예방한의학회지
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• 제12권3호
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• pp.35-45
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• 2008

Purpose : To evaluate safety of Sibjeondaebotang and Yugmijihwangtang in rats' fetus Methods : Female Sprague-Dawley rats were orally administered with the Sibjeondaebotang and Yugmijihwangtang at dose of 5mg/kg/day for 20 days. Pregnant rats were sacrificed at 20th day of gestation. Approximately live fetuses in the 20th day of gestation were randomly selected and fixed in 95% ethanol. To observe skeletal malformations, fetuses were stained with alcian blue and alizarin red S. Results : Neonatal body weight and number of fetus of Sibjeondaebotang, Yugmijihwangtang group were increased to those of control group. The fetuses treated with Sibjeondaebotang, Yugmijihwangtang didn't showed external malformation. Vertebral and sternal skeletal variations were observed in Sibjeondaebotang, Yugmijihwangtang administered group, but compared to the control, those skeletal variations were insignificant. There were no significant changes in number of ribs, cervical, thoracic, lumbar, sacral and caudal vertebrae Conclusion : From these results, it can be concluded that Sibjeondaebotang, Yugmijihwangtang shows no toxicity effects on fetus body weight and number of live fetuses. Although skeletal variations were shown in vertebrate and sternum, Sibjeondaebotang, Yugmijihwangtang did not show significant changes in bone malformation.