Abstract
This study was conducted to examine the effects of dietary oligosaccharide on the blood glucose and serum lipid composition in streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley male rats weighing 150$\pm$10g were randomly assigned to one normal and four STZ-induced diabetic groups. Diabetic groups were classified to basal diet(DM group) 10% xylooligosaccharide diet(DM-XO group) 10% isomaltooligosaccharide(DM-IMO group) and 10% fructooligosaccharide (DM-FO). Diabetes was experimentally induced by intravenous injection of 50 mg/kg of body weight of STZ in citrate buffer (pH 4.3) after feeding of experimental diets for 4 weeks. The rats were fed with experimental diet for further 4 weeks in diabetic state. The oligosaccharide diets were not effected on the body weight food intakes and food efficiency ratio. The oligosaccharide diets were also not effected on the body weight food intakes and food efficiency ratio. The oligosaccharide diets were also not effected on the weights of liver kidney and small intestine but the weight of cecum was significantly increased on the groups of xylooligosaccharide and isomaltooligosaccharide diet. The levels of oral glucose tolerance test was more effectively improved by DM-XO group. The levels of blood glucose were markedly lower in oligosaccharide supplemented groups than that of DM group. The levels of blood glucose were markedly lower in oligosaccharide supplemented groups than that of DM group. Activities of two intestinal enzymes such as lactase and sucrase in DM-XO and DM-FO groups were lower than that of DM group while activity of maltase was lower only in DM-XO in DM-FO groups than that of DM-group respectively. The levels of serum triglyceride in DM-XO group were lower than that of DM-group respectively. The levels of serum triglyceride in DM-XO groups were lower than that of DM group however was no significant differences among the oligosaccharide groups. These results suggest that dietary oligosaccharide may act as functional food to be capable of improving carbohydrate and lipid metabolism in diabetic rats.
본연구에서는 oligo당의 당뇨합병증 예방효과를 규명하기 위하여 올리고당 비공급군(DM군) xylooligo당 공급군(DM-XO군) isomaltooligo당 공급군(DM-IMO군) 및 fruc-tooligo당 공급군(DM-FO군)으로 나누어 각각 식이에 10% 씩 올리고당을 첨가하여 4주간 사육 후 STZ로 당뇨 유발한 후 다시 4주간 사육한 후 이당류 분해효소의 활성, 혈당, 장기무게 및 혈중 중성지질과 콜레스테롤 농도를 관찰하였다. 당뇨유발 실험군에서 체중증가량, 식이섭취량 및 식이효율은 올리고당의 영향은 없었다. 간장, 신장 및 소장무게에는 당뇨군에서 올리고당의 영향이 없었으나 맹장의 무게는 올리고당 비공급당뇨군(DM군)에 비해 DM-XO군과 DM-IMO군은 유의적으로 증가되었다. 당뇨쥐의 경구 당부하 검사에서 DM군에 비해 DM-FO군은 차이가 없었으나 DM-XO과 DM-IMO군들은 내당능 개선효과가 현저하였다. 혈당은 당뇨유발 2주 및 4주에서 DM군에 비해 올리고당 공급군에서 낮았고 그중에서도 DM-XO군이 가장 효과적이었다. 소장내 lactase 및 sucrase의 활성은 DM군에 비해 DM-XO 군과 DM-FO군에서만 유의적으로 감소되었다. 장통과시간은 DM군에 비해 DM-XO군에서 DM군에 비해 유의적으로 감소되었다. 혈청 총 콜레스테롤 농도는 DM군과 DM-FO군은 높았지만 DM-MO군과 DM-IMO군에서는 정상군과 유의적인 차이가 없었다. 결론적으로 oligo당은 당뇨쥐의 혈당 및 혈중 지질조성개선작용의 가능성이 있으므로 당뇨 합병증 예방의 기능성 식품으로서 기대된다.