• Journal of Nutrition and Health
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• 제19권4호
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• pp.246-254
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• 1986

이유한 Sprague Dawley 종의 암컷 흰쥐를 두군으로 나누어 각각 pyridoxine이 충분한 식이 (22mg/kg diet)와 pyridoxine이 부족한 식이 (1.2mg/kg diet0로 성장시킨후, 적절한 시기에 임신시켰다. 태어난 새끼가 이유할 때 결핍식이군을 둘로 나누어, 한쪽은 pyridoxine이 충분한 식이로 바꾸어준후, 세군의 쥐를 생후 10-주까지 성장시켰다. 각 군의 새끼쥐가 각각 0, 3, 7, 10 주 되었을대, 간의 mitochondria 및 cytosolic fraction 에 있는 Asparate aminotransferase [ EC 2.6.1.1] activity 및 pyridoxal phosphate의 함량을 측정하였다. 결핍군의 간 aspartate aminotransterase activity는 mitochondria 및 cytosolic fraction에서 각각 대조군에 비해 유의적으로 낮았으며 10-4 M pyridoxal phosphate를 첨가한 후 측정한 total enzyme activity 는 거의 대조군과 비슷하였다. 3 주이후 pyridoxine 이 충분한 식이로 바구어준 회복군에서도 대조군에 비해 유의적으로 낮았으나, 결핍군보다는 높았다. 이두 fraction 에서의 pyridoxal phosphate 함량은 결핍군이 대조군보다 현저히 낮았으며, 회복군은 대조군과 비슷하였다. 이로써, 장기간에 걸친 pyridoxine결핍이간의 aspartate aminotransferase activity 및 pyridoxal phosphate에 현저한 영향을 미치며 이유기 이후의 식이보충에 의해서도 enzyme activity는 쉽게 회복되지 않음을 알 수있다.

• The Korean Journal of Physiology and Pharmacology
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• 제2권4호
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• pp.471-477
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• 1998

Cyclosporin A (CsA), a widely used immunosuppressant, is well known to cause nephrotoxicity and hypertension as major side effects. The present study was aimed at investigating the effects of CsA-pretreatment on the activities of cytosolic guanylate cyclase (cGC) in relation to the alteration of relaxant responses in the rat thoracic aorta. CsA $(10\;{\mu}M)-preincubation$ for 90 min significantly attenuated the vasodilatation induced by sodium nitroprusside (SNP), a cytosolic guanylate cyclase activator, shifting the dose-response curve to the right. The increase in cGMP contents induced by SNP was markedly attenuated by CsA. SNP ($1\;{\mu}M{\sim}\;mM$) increased the cGC activity dose-dependently, and the increase was completely abolished by CsA. CsA attenuated the SNP-induced cGC activation dose-dependently. The abolishing effect of CsA-pretreatment on the SNP-induced cGC activation was not affected by washing the preparation, suggesting that the inhibition is irreversible. When CsA was added simultaneously with SNP, cGC activation was not attenuated. 1-(5-isoquinolinylsulfonyl)-2-methyl piperazine (H-7), a protein kinase C (PKC) inhibitor, decreased SNP-induced cGC activation and blocked the CsA-attenuation of cGC activation. These results suggest that CsA directly inhibits cGC participating in the CsA-induced impairment of vasodilatation, and that PKC is involved in the inhibitory action of CsA on cGC.

• Journal of Korean Neurosurgical Society
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• 제41권5호
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• pp.306-313
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• 2007

Objective : In permanent distal middle cerebral artery occlusion [pdMCAO] model of rats, the temporal order of subcellular translocation is not fully understood yet. We studied translocation sequence of cytochrome c and apoptosis inducing factor [AIF] after pdMCAO and patterns of expression. Methods : Twenty-one male rats - with ten minutes, 1, 4, 8, 24 and 48 hours of pdMCAO groups - were enrolled. At core and penumbra area of each cerebral cortex, Western blotting of cytochrome c and AIF were performed using cytosolic fractions and then compared with sham specimens. With 48 hours group, the expression of cytochrome c and AIF was examined with immunofluorescent staining. Results : Compared to sham, the cytosolic translocation of cytochrome c significantly increased at all time points [p<0.05]. As early as 10 min after onset of ischemia, it was increased significantly [p<0.01]. The cytosolic translocation of AIF showed gradual increase with the passage of time and significantly increased 8 hours after [p<0.05]. As late as 24 hours and 48 hours after onset of ischemia, there were increased most significantly [p<0.01]. At penumbra, both proteins failed to show significant increase at all time points. At 48 hours after ischemia, colocalization of cytochrome c and AIF were confirmed. Conclusion : Cytosolic translocation of cytochrome c peaks much earlier than that of AIF in pdMCAO model of rat. Caspase dependent apoptosis activates soon after ischemia and later, it can be reinforced by gradually increasing AIF in ischemic core.

• 대한의생명과학회지
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• 제11권1호
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• pp.45-49
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• 2005

The change of catechol-O-methyltransferase (COMT) activity during regeneration of rat liver was studied. Cytosolic, mitochondrial and microsomal COMTs activities were estimated in regenerating rat livers over a period of ten days after $70\%$ (median and left lateral lobes) partial hepatectomy. The values of Km and Vmax in the hepatic enzymes were also measured. The activities of cytosolic and microsomal COMTs in regenerating rat liver after partial hepatectomy were found to be significantly increased between the second and the third day. Whereas the mitochondrial COMT activity did not change. The Vmax values of the cytosolic and microsomal COMTs in the regenerating rat liver were significantly increased at the second day after partial hepatectomy, however, the Km values of the above hepatic enzymes did not vary in all the experimental groups. Therefore, the results suggest that the biosynthesis of COMT was increased during the regeneration of rat liver.

• 대한한의학회지
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• 제21권3호
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• pp.68-76
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• 2000

Object : This study was earned out to examine the effect of Bupleuri Radix on experimental cholestasis, and make clear a part of this mechanism. Methods : Two models of common bile duct ligation group and taurocholate load group after common bile duct ligation were induced, and Bupleuri Radix extract was taken orally for 14 days. In the 1, 2, 4, 7 and l4days after treatment, cytosolic, mitochondrial and microsomal catechol-O-methyltransferase(COMT) activities in liver were measured. Results : The activities of cytosolic, mitochondrial and microsomal COMT increased in the Blupleuri Radix treated group after common bile duct ligation and after taurocholate load and common bile duct ligation. The activities of cytosolic and mitochondrial COMT increased particularly in Blupleuri Radix treated group after taurocholate load and common bile duct ligation. Conclusions : According to the result, it is considered that Blupleuri Radix not only improves cholestatis in liver, but also decreases a genetic synthesis of taurocholic acid.

• Toxicological Research
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• 제16권4호
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• pp.311-315
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• 2000

Previous studies showed that benzoquinone derivatives inhibited platelet aggregation. but there is no information available on their cytotoxicity to platelets. 1n the present study. washed platelets isolated from rats were treated with 1.4-benzoquinone. a representative benzoquinone derivative. to examine its antiaggregating effect and cytotoxicity. 1.4-Benzoquinone significantly inhibited thrombin-induced platelet aggregation. Consistent with this finding. 1.4-benzoquinone suppressed cytosolic calcium increase induced by thrombin. To examine the cytotoxicity by 1 A-benzoquinone in platelets. turbidometry and lactate dehydrogenase release were measured. Treatment with 1.4-benzoquinone resulted in slight cytotoxicity (30% release at 60 min) to platelets. However. the cytotoxicity was not correlated with increase of cytosolic calcium levels in platelets. All these data suggested that 1.4-benzoquinone inhibited thrombin-induced platelet aggregation mediated by inhibition elf calcium level increase and that 1.4-benzoquinone reveals cytotoxicity to some extent without alteration of calcium level in platelets.

• Journal of Plant Biology
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• 제34권3호
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• pp.239-244
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• 1991

Ca2+ is implicated as a second messenger in coupling various stimuli such as hormone, gravity and light. The determine whether or not plant hormones mobilize calcium with different action, we investigated the cytosolic Ca2+ changes by IAA and zeatin in the protoplasts isolated from elongating mesocotyl of maize. IAA increased the influx of Ca2+ due to the calcium channel opening, which was confirmed by using verapamil, calcium channel blocker. On the other hand, zeatin increased the cytosolic Ca2+ by promoting the efflux of Ca2+ derived from cellular organelles. These results suggest that different calcium flux induced by IAA and zeatin plays a role in appropriate response resulting in increase of cell elongation or repression cell elongatoin.

• Archives of Pharmacal Research
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• 제13권1호
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• pp.51-54
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• 1990

Effect of scoparone (6, 7-dimethoxycoumarin) on the hepatic cytosolic sulfotransferase activity was investigated. After treatment with scoparone, hepatic cytosolic sulfotransferase activity was increased with odse and time-dependent manner as compared to control. The $V_{max}$ value (control = 1.33 n moles/mg protein/min, scoparone = 2.39n moles/mg protein/min) without affecting the $K_m$ value for p-nitrophenol was increased by the scoparone treatment. Whereas, the hepatic cytosolic sulfotransferase was not changed by the addition of scoparone in vitro, and was strongly inhibited by the addition of metabolites of scoparone. The results obtained suggest that the characteristics of increase in the enzyme activity may include induction of enzyme proteins, and may be due to the metaboltes of scoparone.

• Plant Resources
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• 제8권3호
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• pp.194-201
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• 2005

A cytosolic ascorbate peroxidase, hydrogen peroxide-scavenging enzyme, was characterized from Codonopsis lanceolata. The cytosolic ascorbate peroxidase cDNA (CAPX) was 983 nucleotides long and possess an open reading frame of 753 bp with 251 amino acids (MW 27.9 kDa) with pI 5.61. The deduced amino acid sequence of CAPX shows high homology to other known cytosolic APXs ($78{\sim}83%$), but the CAPX was clustered independently from compared ten plant APXs. The CAPX gene was highly expressed in leaf and stem tissues, but not in root. When Codonopsis leaves cut using scalpel were soaked in 1 mM hydorgen peroxide, the expression of CAPX gene was suppressed.

• Journal of Photoscience
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• 제2권1호
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• pp.1-5
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• 1995

The activity of phospholipase A$_2$ (PLA$_2$) was identified and characterized from cytosolic and membrane fractions of oat cells, respectively. PLA$_2$ activity was determined fluorometrically in the presence of serum albumin using phospholipids labeled at sn-2-acyl position with 10-pyrenyldecanoic acid. When the cell-free extracts of oat tissues were fractionated by ultracentrifugation at 100,000 x g and the PLA$_2$ activity was assayed, we found that most of the PLA$_2$ activity was revealed from the cytoplasmic fraction rather than from the membrane fraction. The activity of cytosolic PLA$_2$ was dependent on Ca$^{2+}$ concentration and the optimum concentration of Ca$^{2+}$ was found to be 100 $\mu$M. It was also found that PLA$_2$ could be translocated toward the membrane site from the cytosol upon increasing Ca$^{2+}$ concentration. These results might suggest that an increased [Ca$^{2+}$]$_i$ by phytochrome action could promote the translocation of the cytosolic PLA$_2$ toward the membrane site.