• Journal of Life Science
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• v.15 no.2 s.69
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• pp.304-310
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• 2005

This study was carried out to investigate the effect of herbicide paraquat (1,1-dimethyl-4,4-bipyridilium dichloride) on the electron transport system of the cell. When actively growing cells of bacteria were exposed to the 1.0 mM paraquat, more than $50\%$ of the cells were killed at 0 hour. But specific activities of superoxide dismutase (SOD) were not changed at 0 hour of paraquat treatment. Oxido-reductions of NAD (H) by the suspension of bacterial membtane, rat mithochondria and NAD-dependent dehydrogenase were accelerated by paraquat treatment.

• Journal of Nutrition and Health
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• v.30 no.9
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• pp.1067-1072
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• 1997

One known effect of long chain n-3 polyunsaturated fatty acids is their ability to decrease plasma triglycerides. However, identification of the specific n-3 fatty acids and the underlying mechanisms responsible for this change remains uncertain. This present study was designed to evaluate the effects of moderate levels of dietary docosahexaenoic acid (22 :6(n-3)) on modulating plasma triglyderides. Male CD-1 mice were maintained for 15 days on identical diets containing either docosahexahexaenoic acid ethyl ester(1.5%, w/w) or linoleic acid(18 : 2(n-6)) ethyl ester (1.5%, w/w) . Plasma triglycerides were 40% lower in the docosahexaenoic acid group than in the linoleic acid group. Hepatic carnitine palmitoyltransferase activity (a key regulatory enzyme for mitocondria $\beta$-oxidation) was not significantly different between the dietary groups. However, plasma acid soluble acylcarnitine levels (which increase with increasing $\beta$-oxidation )were significantly higher in the decosahexaenoic acid group. This data suggests that plasma triglyceride levels are lower in mice fed diets containing moderate levels of docosahexaenoic acid compared to linoleic acid, but this effect on plasma triglycerides is not modulated through an augmentation of mitochondrial $\beta$-oxidation.

• Journal of Life Science
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• v.8 no.2
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• pp.203-207
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• 1998

NAD4 as a gene encoding NADH dehydrogenase subunit 4 in the micodhondrion from maize has been cloned using RT-PCR and sequenced for examining RNA edited sites. Analysis of mt cDNA sequences showed the typical RNA editing patterns and unusual base changes as well;RNA editing from cDNA sequences occured base change from c to U in most cases, however transitions from t to g and G to A were also observed. Even though those editings appared to be occurred randomly, RNA edited sites showed mostly in exon 1 and exon 4 regions, when compared with NAD4 cDNA from wheat, locations of edited sites did not consistent with each other suggesting that the phenomenon of RNA editing occured randomly not site-specific manner.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.5
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• pp.504-511
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• 2002

Ultrastructure and sperm morphology were investigated Mactra venerifomis, Mactra chinensis, Spisula sacharinensis, Tresus keenae in Mactridae. All the sperm studied were primitive type. They consisted of three parts; the head, the middle piece and the tail part. The acrosome forms were similar among the 4 species. The acrosome was shaped like a modified hat. It was consisted of two different parts in electronic density; the anterior part, electric lucent part (elp), and the posterior part, electric dense part (edp). But nuclei forms were slightly different among the species. All the species studied had 4 mitocondria at middle piece. We guessed that the Mactridae sperm were family-specific with characterful acrosome shape.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.311-315
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• 2005

When paraquat was added to the bacterial membrane or mitochondrial suspension, the mixture turned dark blue, but the color was disappeared by aeration. The same phenomenon was seen when electrons were supplied to the paraquat. Blue color appeared from near the cathode, and then spreaded to whole transit system. Coloration was accelerated by addition of alkali, but the color was reduced by addition of acid or oxygen. Paraquat exhibited absorption at ultraviolet region by electron transfer at the concentrations as low as 1.0 mM which did not exert difficulty in showing color reaction. Paraquat caused the increase of the optical density at 340 nm by electron transit, and an aspect of that had a strong resemblance to NADH. The acute toxic action of paraquat seemes to depend on inhibition of energy metabolism cased by paraquat action of electron donor and acceptor.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.4
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• pp.239-246
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• 2005

In the central nervous system, nitric oxide (NO) is associated with many pathological diseases such as brain ischemia, neurodegeneration and inflammation. The epigallocatechin gallate (EGCG), a major compound of green tea, is recognized as protective substance against neuronal diseases. This study is aimed to investigate the effect of EGCG on NO-induced cell death in PC12 cells. Administration of sodium nitroprusside (SNP), a NO donor, decreased cell viability in a dose- and time-dependent manner and induced genomic DNA fragmentation with cell shrinkage and chromatin condensation. EGCG diminished the decrement of cell viability and the formation of apoptotic morphologenic changes as well as DNA fragmentation by SNP. EGCG played as an antioxidant that attenuated the production of reactive oxygen species (ROS) by SNP. The cells treated with SNP showed downregulation of Bcl-2, but upregulation of Bax. EGCG ameliorated the altered expression of Bcl-2 and Bax by SNP. The release of cytochrome c from mitochondria into cytosol and expression of voltage -dependent anion channel (VDAC)1, a cytochrome c releasing channel in mitochondria, were increased in SNP-treated cells, whereas were attenuated by EGCG. The enhancement of caspase-9, preceding mitochondria-dependent pathway, caspase-8 and death receptor-dependent pathway, as well as caspase-3 activities were suppressed by EGCG. SNP upragulated Fas and Fas-L, which are death receptor assembly, whereas EGCG ameliorated the expression of Fas enhanced by SNP. These results demonstrated that EGCG has a protective effect against SNP-induced apoptosis in PC12 cells, through scavenging ROS and regulating the mitocondria- and death receptor-mediated signal pathway. The present study suggest that EGCG might be a natural neuroprotective substance.