• Environmental Analysis Health and Toxicology
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• 제22권2호통권57호
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• pp.165-170
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• 2007

Elevation of homocysteine levels is a risk factor for cardiovascular diseases and liver diseases. It has been reported that both streptozotocin-induced type I diabetic rats and obese type II diabetic rats have plasma total homocysteine lower than each control rats. We determined the effects of lean type II diabetes on homocysteine levels using type 2 diabetic Goto-Kakizaki rats. The concentrations of serum glucose were increased to ${\sim}two-fold$ of control levels and the total cholesterol levels were also increased in GK rats. Hepatic aspartate, histidine, threonine, alanine and methionine levels were significantly increased in GK rats. Plasma aspartate and glutamate levels were elevated, but threonine and arginine levels were decreased in GK rats. Plasma total homocysteine levels were not changed in GK rats, but hepatic total homocysteine levels were increased to ${\sim}three-fold$ of control levels. These results suggest that hepatic metabolism of sulfur-amino acid may be altered in diabetic condition.

• Nutrition Research and Practice
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• 제3권1호
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• pp.23-30
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• 2009

The aim of this study was to examine the hypoglycemic effect of chlorella in 6 week-old type 2 diabetic Goto-Kakizaki (GK, n=30) rats and 6 week-old normal Wistar (n=30) rats. Animals were randomly assigned to 3 groups respectively, and were fed three different experimental diets containing 0%, 3% or 5% (w/w) chlorella for 8 weeks. In diabetic GK rats, the insulinogenic-indices were not significantly different among the groups. The concentrations of fasting plasma glucagon and hepatic triglyceride, and the insulin/glucagon ratios of the GK-3% chlorella and GK-5% chlorella groups were significantly lower than those of the GK-control group. The HOMA-index and the concentrations of fasting blood glucose and plasma insulin of the GK-3% chlorella and GK-5% chlorella groups were slightly lower than those of the GK-control group. In normal Wistar rats, the insulinogenic-indices were not significantly different among the normal groups, but that of the Wistar-5% chlorella group was slightly higher than the other groups. The concentrations of fasting blood glucose and plasma insulin, and the HOMA-index of the Wistar-5% chlorella group were a little higher, and the fasting plasma glucagon concentration and the insulin/glucagon ratio of the Wistar-5% chlorella group were significantly higher than those of the Wistar-control and Wistar-3% chlorella groups. In conclusion, this study shows that the glucose-stimulated insulin secretion was not affected by the intake of chlorella, which could be beneficial, however, in improving insulin sensitivity in type 2 diabetic GK and normal Wistar rats.

• 한국식품영양과학회지
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• 제43권3호
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• pp.355-359
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• 2014

본 연구에서는 Goto-Kakizaki 당뇨질환 모델을 통해 미네랄이 풍부한 천일염의 항당뇨 효과를 관찰하고자 하였다. 동일한 주령의 Wistar rat 정상군에 비해 소금투여군에서는 간, 신장, 비장 등 장기무게는 유의적으로 증가하는 경향을 보였지만 소금투여군 사이에는 유의성이 나타나지 않았다. 혈중 성분 변화에서는 총 콜레스테롤 함량은 죽염투여군(BS)이 정제염투여군(PS)에 비해 유의적으로 감소하는 경향을 보여주었으며 혈청 중성지방은 모든 천일염투여군이 정제염보다 유의적으로 감소하는 경향을 나타내었다. 혈당수치는 정제염투여군은 실험기간 동안 지속적인 상승추세를 보여주었지만 천일염투여군은 상승하다가 일정 기간에서는 유지되는 경향을 보였으며 12주차 결과에서는 정제염투여군에 비해 유의적인 차이로 혈당 저하 효과를 보였다. 혈중 인슐린 농도는 정제염투여군에서 정상군에 비해 유의적인 감소를 보였으며 천일염투여군에서 다소 상승하는 추세를 보였지만 유의성은 나타나지 않았다. 췌장의 조직학적 변화를 관찰한 결과 정제염투여군에 비해 천일염투여군에서 랑게르한스섬의 배열이 비교적 규칙적이고 원형에 근접하는 형태를 유지하는 것을 확인할 수 있었다. 따라서 본 연구결과를 토대로 미네랄이 풍부한 천일염이 당뇨질환을 완화시킬 수 있는 가능성이 있을 것으로 사료되나 앞으로 이에 대한 보다 심도 있는 메커니즘 연구가 필요하다고 생각된다.

• Nutrition Research and Practice
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• 제3권4호
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• pp.272-278
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• 2009

Postprandial hypoglycemic effect of mulberry leaf (Morus alba L.) was compared in two animal models: Goto-Kakizaki (GK) rats, a spontaneous non-obese animal model for type II diabetes, and their counterpart control Wistar rats. First, the effect of a single oral administration of mulberry leaf aqueous extract (MLE) on postprandial glucose responses was determined using maltose or glucose as substrate. With maltose-loading, MLE reduced peak responses of blood glucose significantly in both GK and Wistar rats (P < 0.05), supporting the inhibition of $\alpha$-glucosidase by MLE in the small intestine. With glucose-loading, MLE also significantly reduced blood glucose concentrations, measured at 30 min, in both animal models (P < 0.01), proposing the inhibition of glucose transport by MLE. Next, dried mulberry leaf powder (MLP) was administered for 8 weeks by inclusion in the diet. By MLP administration, fasting blood glucose was significantly reduced at weeks 4 and 5 (P < 0.05), but then returned to values that were similar to those of the control at the end of experimental period in GK rats. Insulin, HOMA-IR, C-reactive protein, and triglycerides tended to be decreased by MLP treatment in GK rats. All other biochemical parameters were not changed by MLP administration in GK rats. Collectively, these findings support that MLE has significant postprandial hypoglycemic effect in both non-obese diabetic and healthy animals, which may be beneficial as food supplement to manage postprandial blood glucose. Inhibitions of glucose transport as well as $\alpha$-glucosidase in the small intestine were suggested as possible mechanisms related with the postprandial hypoglycemic effect of MLE.

• 한국식품영양과학회지
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• 제40권11호
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• pp.1537-1543
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• 2011

본 연구는 제2형 당뇨동물모델인 Goto-Kakizaki(GK)랫드에 대한 성게껍질의 항당뇨 효과를 조사하였다. 즉 Wistar 랫드로 구성된 정상군, GK랫드 대조군, GK랫드에 성게껍질을 각각 100 mg/kg 및 200 mg/kg 투여군으로 나누고 매일 1회씩 4주간 경구투여 하여 체중, 혈당, 혈장 인슐린 농도 및 경구당부하 검사를 실시하였다. 그 결과 성게껍질을 투여한 GK랫드의 혈당은 203.8${\pm}$29.8 mg/dL에서 138.5${\pm}$21.2 mg/dL로 유의적으로 감소하였다. 그러나 성게껍질투여에 따른 GK랫드의 혈장 내 인슐린 농도의 변화는 없었다. 경구당부하 검사에서 성게껍질을 투여한 GK랫드는 15~120분에서 대조군보다 더 낮은 혈당으로 나타났다. 또한 췌장의 조직학적 변화는 성게껍질을 투여한 랫드에서 전체적인 췌도세포의 크기나 공포성 변화 및 선방세포의 배열 및 크기가 대조군에 비하여 정상군에 근접한 형태로 나타났다. 따라서 성게껍질은 당뇨모델인 GK 랫드의 혈당을 저하시키고 내당능이나 인슐린저항성을 개선하므로 향후 이를 활용하여 항당뇨 식품 및 원료개발에 활용될 것으로 기대된다.

• 한국발생생물학회지:발생과생식
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• 제14권2호
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• pp.75-82
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• 2010

이 연구는 제2형 당뇨 모델 동물인 Goto-Kakizaki(GK) 흰쥐를 사용하여 운동과 셀레늄 투여가 미토콘드리아 생성과 기능 향상을 조절하는 전사 인자의 발현 변화와 현상학적으로 당뇨의 증상 개선을 유도할 수 있는지를 구명하기 위해 실시하였다. 실험동물은 52주령된 GK 수컷 흰쥐로 24 m/min, 30 min/day, 5 days/week, 총 6주간 트레드밀 런닝을 실시하였다. Sodium selenite(5 umol/kg)는 selenium 집단과 combination 집단에 1주일에 5일씩 6주간 복강에 주입하였다. 운동과 셀레늄 투여는 미토콘드리아의 생성에 관여하는 peroxisome proliferators-activated receptor gamma coactivator-1alpha(PGC-$1{\alpha}$), nuclear respiratory factors(NRF-1), 그리고 mitochondrial transcription factor A(Tfam) 발현을 증가시켰으며, 그 결과로 미토콘드리아량의 지표 단백질인 cytochrome C도 증가를 보였다. 특히, 운동이나 셀레늄의 단독적인 처치보다는 운동과 셀레늄 병행 처치가 미토콘드리아의 생성 및 활성 증가, 그리고 포도당 내성에 긍정적인 효과를 보였다. 따라서, 본 연구에서 수행된 운동과 셀레늄 투여 처치는 당뇨의 개선 효과 및 당뇨 질환과 관련된 미토콘드리아의 기능 향상에 긍정적인 효과를 보이는 것으로 나타났다.

• Nutrition Research and Practice
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• 제5권3호
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• pp.205-213
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• 2011

Exercise training (ET) and selenium (SEL) were evaluated either individually or in combination (COMBI) for their effects on expression of glucose (AMPK, PGC- $1{\alpha}$, GLUT-4) and lactate metabolic proteins (LDH, MCT-1, MCT-4, COX-IV) in heart and skeletal muscles in a rodent model (Goto-Kakisaki, GK) of diabetes. Forty GK rats either remained sedentary (SED), performed ET, received SEL, ($5\;{\mu}mol{\cdot}kg$ body $wt^{-1}{\cdot}day^{-1}$) or underwent both ET and SEL treatment for 6 wk. ET alone, SEL alone, or COMBI resulted in a significant lowering of lactate, glucose, and insulin levels as well as a reduction in HOMA-IR and AUC for glucose relative to SED. Additionally, ET alone, SEL alone, or COMBI increased glycogen content and citrate synthase (CS) activities in liver and muscles. However, their effects on glycogen content and CS activity were tissue-specific. In particular, ET alone, SEL alone, or COMBI induced upregulation of glucose (AMPK, PGC-la, GLUT-4) and lactate (LDH, MCT-1, MCT-4, COX-IV) metabolic proteins relative to SED. However, their effects on glucose and lactate metabolic proteins also appeared to be tissue-specific. It seemed that glucose and lactate metabolic protein expression was not further enhanced with COMBI compared to that of ET alone or SEL alone. These data suggest that ET alone or SEL alone or COMBI represent a practical strategy for ameliorating aberrant expression of glucose and lactate metabolic proteins in diabetic GK rats.

• 한국식생활문화학회지
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• 제22권1호
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• pp.157-165
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• 2007

This study was designed to evaluate the effects of fructose(F) or sucrose(S) and guar gum intake on carbohydrate and lipid metabolism in 15-week-old male Goto-Kakizaki(GK) rats. Fifty rats were randomly assigned to 5 groups which were different in carbohydrate(25% of carbohydrate) and fiber(5% w/w) sources. The carbohydrate(CHO) sources of each group were comstarch(control group, 100% of CHO), fructose with cellulose(F), fructose with guar gum(FG), sucrose with cellulose(S), and sucrose with guar gum(SG). Each group was fed exterimental diet for 4 weeks. We measured food intake, body weight gain, adipose tissues weight and organs weight. We conducted oral glucose tolerance test(OGTT) and measured plasma insulin concentration to examine carbohydrate metabolism. To evaluate lipid metabolism, we measured the lipid profile of plasma, liver and feces. Food intake and weight gain of FG or SG groups tended to be less than those of F or S groups. Perirenal and epididymal fat pad weights of SG group were significantly lower than those of S group and those of FG group tended to be lower than those of F group. In OGTT, blood glucose values of F or S groups were significantly higher than those of C group, and FG or SG groups tended to be lower than those of F or S groups during the experimental time. The area under the curve(AUC) of C group was significantly highest among the groups, AUC and plasma insulin concentration of FG or SG groups tended to be lower than those of F or S groups. Plasma and hepatic triglyceride (TG) of FG and SG groups were significantly lower than those of F and S groups, plasma and hepatic total lipid(TL) and total cholesterol(TC) of FG and SG groups tended to be lower than those of F and S groups. Fecal TL, TG and TC of FG or SG groups tended to be higher than those of F and S groups. In conclusion, intake of guar gum should improve carbohydrate and lipid metabolism in partial substitution of fructose or sucrose for cornstarch in GK rats.