• Journal of Preventive Medicine and Public Health
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• 제32권1호
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• pp.101-107
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• 1999

Objectives. To determine the effects of exposure to hexavalent chromium, 93 male Sprague-Dawley rats were exposed to hexavalent chromium solution. Methods. Rats were divided into 4 groups and exposed to 0.1ml of 0 mM, 0.4 mM, 2.0 mM, and 10.0 mM potassium chromate in the first experiment, and to 0.1 ml of 0 mM, 20 mM, 40 mM, and 80 mM in the second for consecutive 3 days by tracheal instillation. Three and 10 rats were the controls for the first and the second experiments, respectively. Lung tissues were then removed to measure the 8-hydroxydeoxyguanosine (8-OH-dG) level using the HPLC-ECD method, superoxide dismutase (SOD) activity using the cytochrome C method, and 8-hydroxyguanine endonuclease activity using the oligonucleotide nicking assay. Results. The results showed no significant linear relationship between chromium exposure level and 8-OH-dG level or 8-hydroxyguanine endonuclease activity. In the first experiment, 8-OH-dG level and 8-hydroxyguanine endonuclease activity increased in 0.4 mM group, and then decreased in 2.0 mM and 10.0 mM groups. The correlation coefficients between 8-OH-dG level and 8-hydroxyguanine endonuclease activity was statistically significant (P<0.01), and total SOD activity was elevated by chromium exposure in a dose-dependent manner (P<0.05). In contrast, there was no significant dose-response pattern or correlation in the secod experiment. Conclusions. Based on the fact that there was no linear relationship between chromium dose and 8-OH-dG level or activity of the repair enzyme, it seems unlikely that 8-OH-dG formation is the major mechanism of chromium carcinogenesis.

• Molecular & Cellular Toxicology
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• 제3권4호
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• pp.215-221
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• 2007

Neuronal cell toxicity induced by decreased nitric oxide (NO) production may be caused by modulation of constitutive neuronal NO synthase (nNOS). We used lead acetate ($Pb^{2+}$) to modulate physiological NO release and the related pathways of protein kinases like PKC, CaM-KII, and PKA in CATH.a cells, a dopaminergic cell line that has constitutive nNOS activity. In the cells treated with $Pb^{2+}$, cell viability and modulation (phosphorylation) levels of nNOS were determined by MTT assay and Western blot analysis, respectively. nNOS reductase activity (cytochrome c) was also assessed to compare the phosphorylation site-specific nNOS activity. nNOS activity was also determined by NADPH consumption rates. $Pb^{2+}$ treatment alone increased the phosphorylation of nNOS with decreased reductase activity. The phosphorylation levels increased markedly with decreased nNOS reductase activity, when $Pb^{2+}$ was combined with inhibitors for two (PKC and CaM-KII) or three (PKA, PKC and CaM-KII) protein kinases. Interestingly, when the cells were exposed to $Pb^{2+}$ plus PKC or CaM-KII inhibitor, the nNOS was phosphorylated strongly with the lowest activity. However, the levels of phosphorylated nNOS following $Pb^{2+}$ treatment decreased significantly after combined treatment with the PKA inhibitor, and $Pb^{2+}$-induced suppression of reductase activity did not occur. These results demonstrate that physiological NO release in the neuronal cells exposed to $Pb^{2+}$ can be decreased by PKA-mediated nNOS phosphorylation that may be caused by interactions with PKC and/or CaM-KII.

• 한국임상수의학회지
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• 제25권3호
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• pp.152-158
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• 2008

We investigated the changes of protein in chronic MI which was occurred with long-term ischemia, without reperfusion. Sprague Dawley (SD) rats were divided into the sham group and the experimental groups (MI groups). The sham group was treated only thoracotomy without ligation for left main descending artery (LMDA) of left coronary artery (LCA), and the experimental groups (MI7d, ligation of LMDA for 7 days and MI30d, ligation of LMDA for 30 days) were conducted an artificial chronic MI. The change of proteins according to passage of times was compared and analyzed on first and second dimension (1 and 2D) sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Among total 46 spots expressed differentially in the sham group versus MI7d and MI30d groups on 2D gel, we selected proteins that the volume of spot was increased in the MI7d and MI30d groups compared with the sham group. After that, the proteins were identified through liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis. In result, we could obtain many proteins as follows; albumin, glucose regulated protein 58 KDa, similar to tripartite motif protein 50, ubiquinol-cytochrome c reductase core protein II, sarcomeric mitochondrial creatine kinase, ATP synthetase alpha chain (mitochondrial precursor) and creatine kinase. In conclusion, we suggest many changed proteins shown at chronic ischemia after artificial MI and consider that these proteins play an important role in the function of heart after MI.

• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.978-984
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• 2004

In the course of screening for a novel inhibitor of CDC2, HY558-1 was isolated from a culture broth of Penicillium minioluteum F558. Moreover, it was found that HY558-1 had an effect on both the cell cycle regulation and apoptosis of human cervical adenocarcinoma HeLa cells. A flow cytometric analysis of HeLa cells revealed appreciable cell cycle arrest at the G1 and G2/M phases following treatment with HY558-1. Furthermore, DNA fragmentation due to apoptosis was observed in HeLa cells treated with HY558-1. To obtain further information on the cell cycle arrest and apoptotic induction induced by HY558-1, the expression of certain cell cycle and apoptosis-associated proteins was examined using a Western blot analysis. The results revealed that HY558-1 inhibited the phosphorylation of pRb and decreased the expression levels of CDK2, CDC2, and cyclin A in the cell cycle progression. It was also shown that the level of $p21^{WAF1/CIP1}$ was increased in HeLa cells treated with 0.52 mM of HY558-1. Accordingly, HY558-1 was found to inhibit the proliferation of HeLa cells through the induction of G1 phase arrest by inhibiting pRb phosphorylation via an upregulation of $p21^{WAF1/CIP1}$, and G2/M phase arrest by directly inhibiting CDC2 and cyclin A. Moreover, HeLa cells treated with 0.52 mM of HY558-1 exhibited apoptotic induction associated with the cleavage of Bid and release of cytochrome c from mitochondria into the cytosol. Subsequent investigation of the activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP) suggested that the mitochondrial pathway was primarily involved in the HY558-1-induced apoptosis in HeLa cells.

• The Korean Journal of Physiology and Pharmacology
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• 제18권1호
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• pp.25-32
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• 2014

Nitric oxide (NO) is recognized as a mediator and regulator of inflammatory responses. NO is produced by nitric oxide synthase (NOS), and NOS is abundantly expressed in the human dental pulp cells (HDPCs). NO produced by NOS can be cytotoxic at higher concentrations to HDPCs. However, the mechanism by which this cytotoxic pathway is activated in cells exposed to NO is not known. The purpose of this study was to elucidate the NO-induced cytotoxic mechanism in HDPCs. Sodium nitroprusside (SNP), a NO donor, reduced the viability of HDPCs in a dose- and time-dependent manner. We investigated the in vitro effects of nitric oxide on apoptosis of cultured HDPCs. Cells showed typical apoptotic morphology after exposure to SNP. Besides, the number of Annexin V positive cells was increased among the SNP-treated HDPCs. SNP enhanced the production of reactive oxygen species (ROS), and N-acetylcysteine (NAC) ameliorated the decrement of cell viability induced by SNP. However, a soluble guanylate cyclase inhibitor (ODQ) did not inhibited the decrement of cell viability induced by SNP. SNP increased cytochrome c release from the mitochondria to the cytosol and the ratio of Bax/Bcl-2 expression levels. Moreover, SNP-treated HDPCs elevated activities of caspase-3 and caspase-9. While pretreatment with inhibitors of caspase (z-VAD-fmk, z-DEVD-fmk) reversed the NO-induced apoptosis of HDPCs. From these results, it can be suggested that NO induces apoptosis of HDPCs through the mitochondria-dependent pathway mediated by ROS and Bcl-2 family, but not by the cyclic GMP pathway.

• Biomolecules & Therapeutics
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• 제9권3호
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• pp.167-175
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• 2001

Recent studies have shown that cytokines are capable of modulating cardiovascular function and that some drugs used in the treatment of heart failure variably modulate the production of cytokines. Hige- namine, a positive inotropic isoquinoline alkaloid, has been used traditionally as cardiac stimulant, and reported to reduce nitric oxide (NO) and inducible nitric oxide synthase (iNOS) expression in LPS- and/or cytokine-activated cells in vitro and in vivo. Therefore, we investigated whether higenamine modulates the production of proinflammatory cytokines in myocardial infarction. In addition, effects of higenamine on antioxidant action and antioxidant enzyme expression (MnSOD) were studied. Myocardial infarction (MI) was confirmed by measuring left ventricular (LV) pressure after occlusion of the left anterior descending coronary artery (LAD) for 5 weeks in rats. Treatment of higenamine (10 mg/kg/day) reduced infarct size about 35 %, which accompanied by reduction of production TNF-$\alpha$, IL-6, but not IFN-${\gamma}$ and IL-1$\beta$ in the myocardium. The expression of TNF-$\alpha$ mRNA in infracted myocardium was significantly reduced by higenamine. Although iNOS mRNA was not detected, nitrotyrosine staining was significantly increased in myocardium of Ml compared to higenamine-treated one, Indicating that peroxynitrite-induced damage is evident in MI. Cytochrome c oxidation by peroxynitrite was concentration-dependently reduced by higenamine, an effect which was almost compatible to glutathion. Higenamine treatment did not affect the expression of MnSOD mRNA in myocardial tissues in MI. Taken together, higenamine may be beneficial in oxidative stress conditions such as ischemic-reperfusion injury and MI due to antioxidant action as well as modulation of cytokines.

• Parasites, Hosts and Diseases
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• 제58권1호
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• pp.93-97
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• 2020

The cestode Taenia hydatigena uses canids, primarily dogs, as definitive hosts, while the metacestode larval stage cysticercus infects a range of intermediate hosts, including domestic animals such as goats, sheep, and pigs. Cysticercosis due to T. hydatigena has large veterinary and economic drawbacks. Like other taeniids, e.g., Echinococcus, intraspecific variation is found among the members of the genus Taenia. In Africa, few studies are available on the epidemiology and distribution of T. hydatigena, and even fewer studies are available on its genetic variation. In this study, we molecularly identified 11 cysticerci from sheep in Sudan and demonstrated the genetic variation based on the NADH dehydrogenase subunit 1 (nad1) and cytochrome c oxidase subunit 1 (cox1) mitochondrial genes. The isolates were correctly identified as T. hydatigena with more than 99% similarity to those in the GenBank database. Low diversity indices and insignificant neutrality indices were observed, with 3 and 2 haplotypes for the nad1 and cox1 genes, respectively. The results suggest the presence of unique T. hydatigena haplotypes in Sudan, as haplotypes with 100% similarity were not found in the GenBank database. With few available studies on the genetic variation of T. hydatigena in Africa, this report represents the first insights into the genetic variation of T. hydatigena in Sudan and constitutes useful data.

• The Korean Journal of Physiology and Pharmacology
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• 제10권5호
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• pp.289-295
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• 2006

Sodium fluoride (NaF) has been shown to be cytotoxic and elicit inflammatory response in human. However, the cellular mechanisms underlying NaF-induced cytotoxicity in periodontal tissues have not yet been elucidated. This study is aimed to investigate the mechanisms of NaF-induced apoptosis in human gingival fibroblast (HGF). NaF decreased the cell viability of HGF in a dose- and time-dependent manner. NaF gave rise to apoptotic morphological changes including cell shrinkage, chromatin condensation, and DNA fragmentation. However, NaF did not affect the production of ROS. In addition, NaF augumented cytochrome c release from mitochondria into the cytosol, and enhanced caspase -9 and -3 activities., cleavage (85 kDa fragments) of poly (ADP-ribose) polymerase (PARP) and upregulation of voltage-dependent anion channel (VDAC) 1. These results demonstrated that NaF-induced apoptosis in HGF may be mediated with mitochondria. Furthermore, NaF elevated caspase-8 activity and upregulated Fas-ligand (Fas-L), suggesting involvement of death receptor mediated pathway in NaF-induced apoptosis. Expression of Bcl-2, an anti-apoptotic Bcl-2 family, was downregulated, whereas expression of Bax, a pro-apoptotic Bcl-2 family, was not affected in NaF-treated HGF. These results suggest that NaF induces apoptosis in HGF through both mitochondria- and death receptor-mediated pathway mediated by Bcl-2 family.

• Parasites, Hosts and Diseases
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• 제57권6호
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• pp.639-645
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• 2019

In the present study, a Spirometra species of Tanzania origin obtained from an African leopard (Panthera pardus) and spotted hyena (Crocuta crocuta) was identified based on molecular analysis of cytochrome c oxidase I (cox1) and NADH dehydrogenase subunit I (nad1) as well as by morphological observations of an adult tapeworm. One strobila and several segments of a Spirometra species were obtained from the intestine of an African male leopard (Panthera pardus) and spotted hyena (Crocuta crocuta) in the Maswa Game Reserve of Tanzania. The morphological characteristics of S. theileri observed comprised 3 uterine loops on one side and 4 on the other side of the mid-line, a uterine pore situated posterior to the vagina and alternating irregularly either to the right or left of the latter, and vesicular seminis that were much smaller than other Spirometra species. Sequence differences in the cox1 and nad1 genes between S. theileri (Tanzania origin) and S. erinaceieuropaei were 10.1% (cox1) and 12.0% (nad1), while those of S. decipiens and S. ranarum were 9.6%, 9.8% (cox1) and 13.0%, 12.6% (nad1), respectively. The morphological features of the Tanzania-origin Spirometra specimens coincided with those of S. theileri, and the molecular data was also consistent with that of S. theileri, thereby demonstrating the distribution of S. theileri in Tanzania. This places the leopard (Panthera pardus) and spotted hyena (Crocuta crocuta) as new definitive hosts of this spirometrid tapeworm.

• 한국조류학회지
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• 제25권2호
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• pp.94-100
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• 2018

몽골의 초원이나 사막과 같은 개방지역에 설치된 송전선로에서 발생하는 조류 감전사고는 매우 흔하게 보고되고 있다. 본 연구는 조류피해조사를 위해 2017년 몽골 남부지역의 준사막 지역에 설치된 15-kV의 송전선로에 4월, 7월, 9월 등 총 3회에 걸쳐 조사를 실시하였다. 전체 250개의 전신주 구간에서 총 12종 45개체의 감전사한 조류를 확인하였다(10㎞마다 1.12% 사망률). 주요 감전 피해 조류는 멸종위기종인 Falco cherrug (n=11)와 Milvus migrans (n=11)로 나타났다. 본 연구지역과 같이 개방된 환경에서의 조류를 위한 잠자리 또는 휴식처의 부족은 보다 많은 조류의 감전사고를 발생시킬 수 있으며, 특히 몽골의 다른 개방지역에서도 발생할 수 있다. 사고현장에서 종동정이 어려운 개체의 경우, 시료의 유전자 증폭 등을 통해 DNA 분석을 실시하여 동정하였다. 본 연구결과 몽골의 개방지역에서 조류의 감전사고는 조류에게 발생하는 위험요소 중 높은 비율을 차지하고 있는 것으로 확인되었으며, 특히 맹금류에게 빈번하며, 간헐적으로 이동철새에게도 일어나고 있는 것으로 확인되었다. 개방된 지역일 경우 조류의 감전사고가 더 잘 발생할 수 있으며, 감전사고와 같은 조류의 위험요소를 보다 잘 이해하는 것은 멸종위기종과 같은 종보전에 기여할 수 있을 것으로 판단된다.