• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2002년도 창립10주년기념 및 국립독성연구원 의약품동등성평가부서 신설기념 국재학술대회:생물학적 동등성과 의약품 개발 전략을 위한 국제심포지움
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• pp.236-236
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• 2002

Pyruvate dehydrogenase phosphatase (PDP) is a mitochondrial protein serine/threonine phosphatase that catalyzes the dephosphorylation and concomitant reactivation of the pyruvate dehydrogenase componant of the pyruvate dehydrogenase complex (PDC). PDP consists of a Mg$\^$+2/ -dependent and Ca$\^$+2)-stimulated catalytic subunit (PDPc) of Mr 52,600 and a FAD-containing regulatory subunit (PDPr) of Mr 95.600. Catalytic subunit of pyruvate dehydrogenase phosphatase (PDPc) has been suggested to have three major functional domains such as dihydrolipoamide acetyltransferase(E$_2$)-binding domain, regulatory subunit of PDP(PDPr)-binding domain, and calcium-binding domain. In order to identify functional domains, recombinant catalytic subunit of pyruvate dehydrogenase phosphatase (rPDPc) was expressed in E. coli JM101 and purified to near homogeneity using the unique property of PDPc: PDPm binds to the inner lipoyl domain (L$_2$) of E$_2$ of pyruvate dehydrogenase complex (PDC) in the presence of Ca$\^$+2/, not under EGTA. PDPc was limited-proteolysed by trypsin, chymotrypsin, Arg-C, and elastase at pH7.0 and 30$^{\circ}C$ and N-terminal analysis of the fragment was done. Chymotrypsin, trypsin, and elastase made two major framents: N-terminal large fragment, approx. 50kD and C-terminal small fragment, approx. 0 kDa. Arg-C made three major fragments: N-terminal fragment, approx. 35 kD, and central fragment, approx. 15 kD, and C-terminal fragment, approx. 10 kD. This study strongly suggest that PDPc consists of three major functional domains. However, further study should be necessary to identify the functional role.

• The Korean Journal of Physiology and Pharmacology
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• 제26권2호
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• pp.125-133
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• 2022

Carbon monoxide (CO) is a known gaseous bioactive substance found across a wide array of body systems. The administration of low concentrations of CO has been found to exert an anti-inflammatory, anti-apoptotic, anti-hypertensive, and vaso-dilatory effect. To date, however, it has remained unknown whether CO influences atrial natriuretic peptide (ANP) secretion. This study explores the effect of CO on ANP secretion and its associated signaling pathway using isolated beating rat atria. Atrial perfusate was collected for 10 min for use as a control, after which high atrial stretch was induced by increasing the height of the outflow catheter. Carbon monoxide releasing molecule-2 (CORM-2; 10, 50, 100 μM) and hemin (HO-1 inducer; 0.1, 1, 50 μM), but not CORM-3 (10, 50, 100 μM), decreased high stretch-induced ANP secretion. However, zinc porphyrin (HO-1 inhibitor) did not affect ANP secretion. The order of potency for the suppression of ANP secretion was found to be hemin > CORM-2 >> CORM-3. The suppression of ANP secretion by CORM-2 was attenuated by pretreatment with 5-hydroxydecanoic acid, paxilline, and 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one, but not by diltiazem, wortmannin, LY-294002, or NG-nitro-L-arginine methyl ester. Hypoxic conditions attenuated the suppressive effect of CORM-2 on ANP secretion. In sum, these results suggest that CORM-2 suppresses ANP secretion via mitochondrial K_ATP channels and large conductance Ca²⁺-activated K⁺ channels.

• 대한약리학회지
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• 제27권1호
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• pp.45-52
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• 1991

GS354와 GS389의 세포내 칼슘{$[Ca^{2+}]_{1}:$ Fura-2의 형광으로 측정}과 근장력 변화에 대하여 백서의 흉부동맥을 사용하여 검토하였다. GS354와 GS389 모두 고농도의 포타슘과 노어에피네프린에 의한 수축을 억제시켰다. GS354의 헐관이완은 $[Ca^{2+}]_{1}$의 감소가 동반되었고 고농도의 포타슘에 의한 $[Ca^{2+}]_{1}$증가억제 현상도 칼슘통로 활성제인 Bay K8644에 의하여 길항되었다. 그러나 혈관이완 작용은 Bay K8644에 의해 억제 되지 않았다. 이러한 사실은 GS354는 칼슘통로를 차단하여 $[Ca^{2+}]_{1}$을 감소시키며 또한 수축기구에 대한 칼슘의 감수성을 낮추는 것을 암시하는 결과이다. 한편 GS389는 세포내 형광성을 증가시켰으나 이것은 Fura-2에 의한 형광이 아니라 내인성 피리딘 뉴클레오타이드에 의한 것으로서 나타났다. 이것은 미토콘드리아 기능을 억제하는 것을 의미하며 이러한 현상때문에 GS389에 대한 $[Ca^{2+}]_{1}$의 측정이 곤란하였으나 계속하여 Bay K8644를 첨가하여 본 결과 형광은 더욱 증가 되었으나 혈관이완은 역전되지 않았다. 이러한 사실은 GS389가 칼슘통로를 억제하며 아울러 수축기구에 대한 칼슘의 감수성을 낮추는 것을 암시하는 결과로 사료된다.

• Applied Microscopy
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• 제24권4호
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• pp.61-77
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• 1994

The calcium-binding proteins (CaBP), parvalbumin (PV) and calbindin-D 28K (calbindin) are particularly abundant and specific in their distribution, and present in different subsets of neurons in many brain regions. Although their physiological roles in the neurons have not been elucidated, they are valuable markers of neuronal subpopulations for anatomical and developmental studies. This study is designed to characterize dorsal lateral geniculate nucleus (dLGN) neurons and axon terminals in terms of differential expression of immunoreactivity (IR) for two well-known CaBPs, PV and calbindin. The experiments were carried out on 6 adult monkeys. Monkeys were perfused under deep Nembutal anesthesia with 2% paraformaldehyde and 0.2% glutaraldehyde in 0.1M phosphate buffer. After removal, the brains were postfixed for 6-8 hr in 2% paraformaldehyde at $4^{\circ}C$ and infiltrated with 30% sucrose at $4^{\circ}C$. Thereafter, they were frozen in dry ice. Serial sections of the thalamus, at $20{\mu}m$, were made in the frontal plane with a sliding microtome. The sections were stained for PV and calbindin with indirect immunocytochemical methods. For electron microscopy, after infiltration with 30% sucrose the blocks of thalamus were serially sectioned at $50{\mu}m$ with a Vibratome in the coronal plane and stained immediately by indirect ABC methods without Triton X-100 in incubation medium. Stained sections were postfixed in 0.2% osmium tetroxide, dehydrated and flat-embedded in Spurr resin. The block was then trimmed to contain only a selected lamina or interlaminar space. The dLGN proper showed strong PV IR in fibers in all laminae and interlaminar zones. Particularly dense staining was noted in layers 1 and 2 that contain many stained fibers from optic tract. Neuronal cell body stained with PV was concentrated only in the laminae. In these laminae staining was moderate in cell bodies of all large and medium-sized neurons, and was strong in cell bodies of some small neurons together with their processes. Calbindin IR was marked in the neuronal cell body and neuropil in the S layers and interlaminar zones whereas moderate in the neuropil throughout the nucleus. Regional difference in distribution of PV and calbindin IR cell is distinct; the former is only in the laminae and the latter in both the S layer and interlaminar space. The CaBP-IR elements were confined to about $10{\mu}m$ in depth of Vibratome section. The IR product for CaBP was mainly associated with synaptic vesicle, pre- and post-synaptic membrane, and outer mitochondrial membrane and along microtubule. PV-IR was noted in various neuronal elements such as neuronal soma, dendrite, RLP, F, PSD and some myelinated or unmyelinated axons, and was not seen in the RSD and glial cells. Only a few neuronal components in dLGN was IR for calbindin and its reaction product was less dense than that of PV, and scattered throughout cytoplasm of soma of some relay neurons, and was also persent in some dendrite, myelinated axons and RLP. The RSD, F, PSD and glial elements were always non-IR for calbindin. Calbindin labelled RLP were presynaptic to unlabeled dendrite or dendritic spine and PSD. Calbindin-labeled dendrite of various sizes were always postsynaptic to unlabeled RSD, RLP or F. From this study it is suggested that dLGN cells of different functional systems and their differential projection to the visual cortex can be distinguished by differential expression of PV and calbindin.

• 대한약리학회지
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• 제14권1_2호
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• pp.1-11
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• 1978

가토 심실근에서 추출한 mitochondria에서 $Na^+$ 및 $K^+$이온에 의한 $Ca^{++}$ 유리작용을 관찰하였다. 반응액에 첨가한 1-3mM의 소량 $Na^+$은 mitochondria막에 미리 결합되어있던 $Ca^{++}$을 현저히 유리시켰으며, $K^+$은 단독으로는 $Ca^{++}$ 유리를 유도하지 않았으나 $Na^+$에 의한 $Ca^{++}$ 유리에 대하여는 $Na^+/K^+$비에 따라 그것이 클수록 $Ca^{++}$ 유리를 증가시켰다. 간 및 신장 mitochondria에서도 $Na^+$에 의하 $Ca^{++}$ 유리현상을 보였으나 심근mitochondria에 비하여 $Na^+$에 대한 감수성이 훨씬 미약하여 약 $1/10{\sim}1/5$에 지나지 않았다. 이와같은 mitochondria의 $Ca^{++}$ 유리현상은 비교적 $Na^+$에 특이한 작용이었으며 다른 일가양이온중에서는 $Li^+$에 의해서만 어느 정도 보였다. 부전심근 mitochondria에서의 $Na^+$에 의한 $Ca^{++}$유리는 정상심근 mitochondria에서와 같았으며 이때 digitalis 강심배당체가 직접적으로는 별 영향을 미치지 않았다. 이상에서 심근의 경우 mitochondria는 세포내 $Ca^{++}$을 조절할 수 있는 기구로서 심근수축의 E-C coupling과정에서 세포막의 전기적 흥분현상과 결부하여 $Ca^{++}$을 유리할 수 있을 것으로 추정하였으며, 한편 digitalis배당체의 강심작용기전에 있어서는 digitalis 배당체에 의한 세포막의 $Na^+$, $K^+$-ATPase 억제결과 초래될 수 있는 세포내의 $Na^+$ 증가 및(또는) $K^+$감소가 간접적으로 mitochondria에서부터 $Ca^{++}$ 유리를 증가하여 E-C coupling 과정을 촉진할 수 있을 것을 사료하였다.