• The Korean Journal of Physiology and Pharmacology
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• 제5권2호
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• pp.157-163
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• 2001

The effects of dimethyl sulfoxide (DMSO) were studied in two groups of Xenopus oocytes, one expressing ATP sensitive $K^+\;(K_{ATP})$ channel comprised of sulfonylurea receptor SUR1 and inwardly rectifying $K^+$ channel subunit Kir6.2, and the other expressing renal $K_{ATP}$ channel ROMK2. At concentrations of $0.3{\sim}10%$ (vol/vol) DMSO inhibited whole cell Kir6.2/SUR1 currents elicited by bath application of sodium azide (3 mM) in a concentration-dependent manner. The inhibition constant and Hill coefficient were 2.93% and 1.62, respectively. ROMK2 currents, however, was not affected significantly by DMSO. The results support the idea that DMSO inhibits $K_{ATP}$ channel expressed in Xenopus oocyte through a protein-specific mechanism(s) that remains to be further elucidated.

• 한국식품저장유통학회지
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• 제9권1호
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• pp.51-55
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• 2002

느타리버섯을 이용하여 김치를 제조한 후 숙성 중 식품학적 특성을 조사하였다. 느타리버섯 김치의 숙성기간에 따른 pH를 측정한 결과 생 느타리버섯 김치는 처음에 대조구인 배추김치보다 높았으나, 숙성기간이 지남에 따라 그 값이 배추김치에 비하여 낮게 나타났으며, 데친 느타리버섯 김치는 배추김치보다 조금 높게 나타났고, 적정산도는 pH의 경우와 반대현상으로 나타났다. 아미노태 질소 함량은 숙성기간이 지남에 따라 증가하는 경향이었는데, 생 느타리버섯 김치는 배추김치에 비하여 그 함량이 높게 나타났으며, 데친 느타리버섯 김치는 배추김치와 비슷하게 나타났다. 김치의 환원당은 숙성기간이 지남에 따라 크게 감소하였는데, 생느타리 버섯 김치의 함량은 배추김치보다 높게 나타났고, 데친 느타리버섯 김치는 조금 낮게 나타났다. 배추김치의 생균수는 숙성 2일째는 급격하게 증가하였으며, 그 이후는 거의 비슷한 수로 나타났다. 느타리버섯 김치도 배추김치와 같은 경향이었는데, 그 수는 배추김치보다 약간 낮게 나타났으며, 젖산균수의 경우는 생균수 거의 같은 경향이었다. 상온에서 1일간 저장한 느타리버섯 김치의 관능검사결과 데친 느타리버섯 김치에 비하여 생느타리버섯 김치가 좋은 값을 나타내었으나, 배추김치에 비하여 기호도가 낮게 나타났다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2002년도 제9회 학술 발표회 프로그램과 논문초록
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• pp.19-19
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• 2002

The gating kinetics of an inward-rectifier K$\^$＋/ channel, ROMK2 (Kir1.lb), were described by a model having one open state and two closed states. The long closed state was abolished by EDTA, suggesting that it was due to block by divalent cations. These closures exhibit a biphasic voltage-dependence, implying that the divalent blockers can permeate the channel.(omitted)

• Childhood Kidney Diseases
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• 제9권2호
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• pp.255-262
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• 2005

신생아 Bartter 증후군 환아를 조기에 진단하고 조기에 치료하는 것은 정상 성장과 발달을 얻을 수 있을 뿐만 아니라, 고칼슘뇨증과 신석회화의 진행을 막고 만성신부전으로의 이행을 예방할 수 있어 중요하다. 이에 저자들은 생후 6개월에 진단하고 인도메타신과 경구칼륨투여로 증상의 호전을 보인 신생아 Bartter 증후군 1례를 보고하는 바이다.

• The Korean Journal of Physiology and Pharmacology
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• 제7권5호
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• pp.267-273
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• 2003

We have investigated the effect on inducing substate(s) of positively charged residues replaced in position 172 of the second transmembrane domain in murine inward rectifier potassium channels, formed by stable or transient transfection of Kir2.1 gene in MEL or CHO cells. Single channel recordings were obtained from either cell-attached patches or inside-out patches excised into solution containing 10 mM EDTA to rule out the effect of $Mg^{2+}$ on the channel gating. The substate(s) could be recorded with all mutants D172H, D172K and D172R. The unitary current-voltage (I-V) relation was not linear with D172H at $pH_i$ 6.3, whereas the unitary I-V relation was linear at $pH_i$ 8.0. The relative occupancy at $S_{LC}$ was increased from 0.018 at $pH_i$ 8.0 to 0.45 at $pH_i$ 5.5. In H-N dimer, that was increased from 0.016 at $pH_i$ 8.0 to 0.23 at $pH_i$ 5.5. The larger the size of the side chain or $pK_a$ with mutants (D172H, D172K and D172R), the more frequent the transitions between the fully open state and substate within an opening. The conductance of the substate also depended upon the pKa or the size of the side chain. The relative occupancy at substate $S_{LC}$ with monomer D172K (0.50) was less than that in K-H dimer (0.83). However, the relative occupancy at substate with D172R (0.79) was similar to that with R-N dimer (0.82). In the contrary to ROMK1, positive charge as well as negative charge in position 172 can induce the substate rather than block the pore in murine Kir2.1. The single channel properties of the mutant, that is, unitary I-V relation, the voltage dependence of the mean open time and relative occupancy of the substates and the increased latency to the first opening, explain the intrinsic gating observed in whole cell recordings.