• The Korean Journal of Physiology
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• 제30권2호
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• pp.257-267
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• 1996

Diabetes mellitus is associated with a wide range of pathophysiologic changes in the kidney. This study was designed to examine the mechanisms by which glucose modulates the expression of polarized membrane transport functions in primary cultured rabbit renal proximal tubule cells. Results are as follows: The rate of 30 minute $Rb^{+}$ uptake was significantly higher($137.76{\pm}5.40%$) in primary renal tubular cell cultures treated with 20 mM glucose than that of 5 mM glucose. Not the level of mRNA for the ${\alpha}$ subunit of Na, K-ATPase but that of ${\beta}$ subunit was elevated in primary cultures treated with high glucose. The initial rate of methyl-${\alpha}$-D-glucopyranoside(${\alpha}$-MG) uptake was significantly lower($71.91{\pm}3.02%$) in monolayers treated with 20 mM glucose than that of 5 mM glucose. There was a tendency of an increase in phlorizin binding site in cells treated with 5 mM glucose. However, 3-O-methyl-D-glucose(3-O-MG) uptake was not affected by glucose concentration in culture media. TPA inhibited $Rb^{+}$ uptake by $63.61{\pm}1.94\;and\;45.80{\pm}1.36%$ and ${\alpha}$-MG uptake by $48.54{\pm}3.69\;and\;41.87{\pm}6.70%$ in the cells treated with 5 and 20 mM glucose, respectively. Also TPA inhibited mRNA expression of Na/glucose cotransporter in cells grown in 5mM glucose medium. cAMP significantly stimulated ${\alpha}$-MG uptake by $114.65{\pm}5.70%$ in cells treated with 5mM glucose, while it did not affect ${\alpha}$-MG uptake in cell treated with 20 mM glucose. However, cAMP inhibited $Rb^{+}$ uptake by $76.69{\pm}4.16\;and\;66.87{\pm}2.41%$ in cells treated with 5 and 20 mM glucose, respectively. In conclusion, the activity of the renal proximal tubular Na,K-ATPase is elevated in high glucose concentration. In contrast, the activity of the Na/glucose cotransport system is inhibited. High glucose may in part affect the activity of the Na,K-ATPase and the Na/glucose cotransport system by controlling the protein kinase C and/or A signal transduction pathway in primary cultured renal proximal tubule cells.

• 한국어류학회지
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• 제32권3호
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• pp.117-129
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• 2020

생물의 종 구분에 이용하는 지표 중 체색은 특징이 뚜렷한 형태 지표로서, 어류의 종 동정에 유용한 형태형질이다. 개볼락은 한국 중부와 남부, 일본 홋카이도 남쪽 등지에 분포하는 상업적으로 중요한 어종으로, 피부에 반점의 유무 및 마킹이 있는 위치에 따라 4개의 아종으로 구분하는 복잡한 체색 특성을 갖는다. 그러나 개볼락의 다양한 체색 패턴과 관련된 유전자 탐색 및 유전자 변이 발굴 등 체색 형성에 관여하는 유전자 규명에 관한 연구는 없다. 이에 따라 본 연구에서는 개볼락의 체색 패턴 관련 유전자 발굴 및 유전자 발현 특성을 규명하기 위한 기초 연구로 체색 타입별 피부 전사체를 프로파일링하였다. 개볼락을 Wild type (반점과 marking 없음)과 Color type (반점과 마킹 모두 있음)으로 구분하였고, 피부 전사체를 RNA-seq 방법을 이용하여 분석하였다. 개볼락 피부 전사체의 발현량을 비교하여 체색 타입별 차등발현유전자 164개를 확보하였다. 이들 차등발현유전자의 기능을 Gene ontology(GO) 분석으로 확인한 결과, 2개는 molecular function, 46개는 biological process, 6개는 cellular component 기능그룹에 속하였다. 차등발현유전자 중 CTL (Galactose-specific lectin nattectin), CUL1 (Cullin-1), CMAS (N-acylneuraminate cytidylyltransferase), NMRK2 (Nicotinamide riboside kinase 2), ALOXE3 (Hydroperoxide isomerase ALOXE3), SLC4A7 (Sodium bicarbonate cotransporter 3) 등은 특정 체색 타입 특이적인 발현양상을 나타냈다. 이번 연구는 개볼락의 체색 패턴 형성에 관여하는 전사체를 탐색한 첫 번째 연구로, 체색 형성 관련 기능유전자 발굴을 위한 후보유전자로 개볼락의 체색 타입별 차등발현유전자를 확보한 것에 의의가 있다. 향후에는 이들 후보유전자의 발현양상 및 기능을 분석하여 개볼락의 복잡한 체색 패턴과 관련된 기능유전자의 특성을 밝히고자 한다.

• 한국어병학회지
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• 제24권1호
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• pp.11-18
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• 2011

본 연구는 여윔증상을 보이는 넙치의 병태생리학적 변화를 관찰하는 것으로 목적으로 하였다. 여윔넙치가 발생한 수조 내의 정상넙치와 여윔넙치의 혈장 삼투압을 측정한 결과, 정상적인 해산어의 삼투압(280~330 mOsm/L)보다 훨씬 높은 약 361과 405 mOsm/L로 각각 나타났다. 이러한 사실은 여윔넙치와 동일한 수조 내의 정상넙치의 삼투압 조절기능에 이상이 있음을 시사하고 있다. 또한, 외관상 증상을 나타내고 있지 않으나, 여윔넙치가 발생한 수조의 정상적인 넙치는 여윔증상이 나타나기 이전의 초기단계로 정의할 수 있다. H&E염색을 통하여 여윔넙치의 장을 관찰한 결과, 여윔넙치의 전장에서는 상피세포가 남아 있기는 하나, 점막하 조직에서는 염증반응이 확인되었으며, 전장의 영양물질 흡수 기능에 손상이 야기되어 있을 가능성이 시사되었다. 그리고 후장의 경우 점막상피는 거의 손실되었으며, 직장에서는 점막상피의 소실과 아울러 소화관 고유의 folding 구조가 거의 확인되지 않았다. 면역염색의 결과에서도 장의 상피조직이 손실됨으로써 점막상피에 존재하는 $Na^+/K^+/2Cl^-$ (NKCC) cotransporter 에 대한 면역반응이 확인되지 않았다. 따라서, 해산어의 수분흡수의 중요한 장소인 후장과 직장의 상피조직이 심하게 손실됨으로써 넙치의 삼투조절기능의 균형이 깨지고 탈수현상이 보이고 따라서 여윔증상이 나타난 것으로 여겨진다. 뿐만 아니라 전장의 조직학적 변화를 통한 여윔증상에 대한 영양학적 관점에서의 고찰이 이루어져야 한다. 양식넙치의 여윔증 원인분석을 위해서 여윔증상 개체뿐만 아니라 여윔증상을 보이다가 회복된 개체에 대한 검토도 필요하다.

• Clinical and Experimental Pediatrics
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• 제45권3호
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• pp.413-417
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• 2002

증후군은 원위세뇨관 Na-Cl 공동운반체 유전자 이상으로 발생하는 상염색체 열성 유전질환으로, 저칼륨혈증, 저마그네슘혈증, 대사성 알칼리증, 그리고 저칼슘뇨증 등의 임상적 특징을 보이는 질환이다. 저자들은 Bartter 증후군과의 감별진단과 Gitelman 증후군의 확진을 위해 임상적으로 Gitelman 증후군이 의심되는 두명의 환아에서 신장청소검사를 시행하였다. 각각의 환아는 밤사이 금식을 시킨 후 물 20 mL/kg를 30분에 걸쳐 경구 투여하였고, 곧 이어 half saline을 정맥을 통해 분당 5 mL의 속도로 투여하기 시작하였다. 소변양이 분당 10 mL에 도달했을 때의 검체로 삼투질제거율, 유리수분제거율, 염소제거율, 원위분획염소재흡수율을 계산하였다. 그 후에 첫째 날은 furosemide, 둘째 날은 hydrochlorothiazide를 각각 투여하고 나서 같은 신장청소검사를 시행하였다. 이뇨제를 투여하기 전 원위분획염소재흡수율은 각각 73%, 75%로 정상범위에서 약간 감소되어 있었다. furosemide를 투여한 후 삼투질제거율은 증가하였고 유리수분제거율은 감소하였다. 염소제거율은 10배 이상 증가하였으며, 원위분획염소재흡수율은 현저한 감소를 보였다. Thiazide를 투여한 후에는 위와 같은 청소율의 변화들을 관찰할 수 없었다. 신장청소 검사의 소견은 본 연구의 환아들이 헨레의 고리 상행각의 이상보다는 원위세뇨관 Na-Cl 공동운반체의 이상이 있음을 보여주고 있어 Gitelman 증후군의 병태 생리와 잘 일치한다고 사료된다.

• Korean Circulation Journal
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• 제54권5호
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• pp.256-267
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• 2024

Background and Objectives: Accumulating evidence shows that sodium-glucose cotransporter 2 inhibitors (SGLT2is) reduce adverse cardiovascular outcomes. However, whether SGLT2i, compared with other antidiabetic drugs, reduce the new development of atrial fibrillation (AF) is unclear. In this study, we compared SGLT2i with dipeptidyl peptidase-4 inhibitors (DPP-4is) in terms of reduction in the risk of AF in individuals with type 2 diabetes. Methods: We included 42,786 propensity score-matched pairs of SGLT2i and DPP-4i users without previous AF diagnosis using the Korean National Health Insurance Service database between May 1, 2016, and December 31, 2018. Results: During a median follow-up of 1.3 years, SGLT2i users had a lower incidence of AF than DPP-4i users (1.95 vs. 2.65 per 1,000 person-years; hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.55-0.97; p=0.028]). In individuals without heart failure, SGLT2i users was associated with a decreased risk of AF incidence (HR, 0.70; 95% CI, 0.52-0.94; p=0.019) compared to DPP-4i users. However, individuals with heart failure, SGLT2i users was not significantly associated with a change in risk (HR, 1.04; 95% CI, 0.44-2.44; p=0.936). Conclusions: In this nationwide cohort study of individuals with type 2 diabetes, treatment with SGLT2i was associated with a lower risk of AF compared with treatment with DPP-4i.

• Journal of Cardiovascular Imaging
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• 제30권3호
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• pp.153-168
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• 2022

Recent studies have shown that sodium/glucose cotransporter 2 (SGLT2) inhibitors might exert favourable changes on cardiac parameters as observed on cardiovascular imaging. We conducted a systematic review and meta-analysis to determine the effects of SGLT2 inhibitors on cardiac imaging parameters. Four electronic databases (PubMed, Embase, Cochrane, Scopus) were searched for studies in which the effects of SGLT2 inhibitors on cardiac imaging parameters were examined. Studies in which a population was administered SGLT2 inhibitors and analysed by echocardiography and/or cardiac magnetic resonance (CMR) imaging were included. Random-effects pair-wise meta-analysis models were utilized to summarize the studies. A total of 11 randomized controlled trials was included with a combined cohort of 910 patients. Comparing patients receiving SGLT2 inhibitors with subjects receiving placebo, the mean change in CMR-measured left ventricular mass (LVM) was -3.87 g (95% confidence interval [CI], -7.77 to 0.04), that in left ventricular end-systolic volume (LVESV) was -5.96 mL (95% CI, -10.52 to -1.41) for combined LVESV outcomes, that in left atrial volume index (LAVi) was -1.78 mL/m² (95% CI, -3.01 to -0.55) for combined LAVi outcomes, and that in echocardiography-measured E/e' was -0.73 (95% CI, -1.43 to -0.03). Between-group differences were not observed in LVM and LVESV after indexation. The only between-group difference that persisted was for LAVi. Treatment with SGLT2 inhibitors resulted in reduction in LAVi and E/e' on imaging, indicating they might have an effect on outcomes associated with LV diastolic function.

• BMB Reports
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• 제38권2호
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• pp.211-217
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• 2005

Cordyceps, an entomopathogenic fungus, contains many health-promoting ingredients. Recent reports indicate that the consumption of cordyceps helps reduce blood-sugar content in diabetics. However, the mechanism underlying this reduction in circulatory sugar content is not fully understood. Methanolic extracts were prepared from the fruiting bodies of Paecilomyces tenuipes, and 4-beta acetoxyscirpendiol (4-ASD) was eventually isolated and purified. $Na^+$/Glucose transporter-1 (SGLT-1) was expressed in Xenopus oocytes, and the effect of 4-ASD on SGLT-1 was analyzed utilizing a voltage clamp and by performing 2-deoxy-D-glucose (2-DOG) uptake studies. 4-ASD was shown to significantly inhibit SGLT-1 activity compared to the non-treated control in a dose-dependent manner. In the presence of the derivatives of 4-ASD (diacetoxyscirpenol or 15-acetoxyscirpendiol), SGLT-1 activity was greatly inhibited in an 4-ASD-like manner. Of these derivatives, 15-acetoxyscirepenol inhibited SGLT-1 as well as 4-ASD, whereas diacetoxyscirpenol was slightly less effective. Taken together, these results strongly indicate that 4-ASD in P. tenuipes may lower blood sugar levels in the circulatory system. We conclude that 4-ASD and its derivatives are effective SGLT-1 inhibitors.

• Journal of Yeungnam Medical Science
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• 제34권1호
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• pp.101-105
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• 2017

Gitelman syndrome is a condition caused by a mutation of the thiazide sensitive Na-Cl cotransporter gene on the distal convoluted tubule. It results in a variety of clinical features, including hypokalemia, hypomagnesemia, hypocalciuria, and metabolic alkalosis. It is often diagnosed in asymptomatic adults presented with unexplained hypokalemia; however, it is sometimes associated with muscular cramps, numbness, fatigue, weakness, or paralysis. We experienced a case of rheumatoid arthritis accompanied by Gitelman syndrome, presented with hand tremor. We diagnosed her using renal clearance study and genetic analysis. Here, we report our experiences regarding this case along with a literature review.

• Asian-Australasian Journal of Animal Sciences
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• 제22권2호
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• pp.232-237
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• 2009

The expression of SGLT-1 mRNA has been reported in the small intestine of mammals and the rectum of chickens. However, the expression and functional significance of SGLT-1 in bovine rectum is not known. In this study, we studied the effects of fasting and grazing on SGLT-1 gene expression in biopsy epithelial tissue of bovine rectum. In Japanese Black beef cattle, i) SGLT-1 gene expression was measured by quantitative real-time PCR in the biopsy rectal epithelia samples obtained through an endoscope, ii) SGLT-1 gene expression in the rectal epithelial tissues increased at 48 and 72 h after fasting correlating with a decrease in body weight. iii) SGLT-1 gene expression decreased after one month from the start of grazing (May to June) and then stabilized until the end of the grazing period (June to October) in the rectal epithelial tissues of grazing cattle. In conclusion, it is clear that SGLT-1 gene expression in the rectal epithelial tissue is increased by a restricted dietary condition.

• 약학회지
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• 제52권6호
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• pp.500-506
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• 2008

Apigenin, a natural flavonoid found in a variety of vegetables and fruits, has been shown to possess many biological functions. In this study we found that apigenin stimulated melanin synthesis in a dose-dependent manner in B16 murine melanoma cells. Since in our previous study $K^+$-$Cl^-$-cotransport (KCC) has been shown to mediate the mechanism of action of apigenin in neuronal cells, we further investigated the role of KCC in the melanogenesis-stimulating effect of apigenin in B16 cells. At nontoxic concentrations apigenin induced $Cl^-$-dependent $K^+$ efflux, a hallmark of KCC activity, which was markedly prevented by a specific KCC inhibitor R-(+)-[(2-n-butyl-6,7-dichloro-2-cyclopentyl-2,3-dihydro-1-oxo-1H-inden-5-yl)oxy]acetic acid (DIOA). These results indicate that KCC is functionally present, and activated by apigenin in the B16 cells. In addition, the apigenin-induced stimulation of melanogenesis was also significantly inhibited by DIOA. NEthylmaleimide (NEM), a known KCC activator, induced $Cl^-$ efflux and stimulated melanogenesis in a concentration-dependent fashion. Both effects of NEM were significantly inhibited by DIOA. Taken together, these results suggest that apigenin can modulate melanogenesis through the activation of a membrane ion transporter, KCC in B16 cells. These results further suggest that apigenin may be a good candidate in the therapeutic strategy for hypopigmentation disorders, such as vitiligo.