Effects of Zinc on the Antioxidative Enzymatic System and Metallothionein Synthesis in Streptozotocin-induced Diabetic Rats

Zinc 투여가 Streptozotocin 유발 당뇨쥐의 항산화효소계와 Metallothionein합성에 미치는 영향

  • Choe, Won-Kyung (Dept. of Food Science and Nutrition, Kimchun Junior College) ;
  • Rhee, Soon-Jae (Dept. of Food Science and Nutrition, Catholic University of Daegu Hyosung)
  • 최원경 (김천전문대학 식품영양과) ;
  • 이순재 (대구효성가톨릭대학교 식품영양학과)
  • Published : 1997.04.01

Abstract

The present study was carried out to investigate the effects of zinc and vitamin E on the antioxidative defense mechanism in the liver of streptozotocin(STZ)-induced diabetic rats. Levels of blood glucose of STZ-diabetic rats were higher than that of control, but ZDM($ZnSO_{4}$ 10mg/kg injection+STZ) group was lower than those of DM(STZ injection) and EDM(vitamin E 400mg/kg diet+STZ) group. Levels of plasma insulin were lower in all three STZ-diabetic groups than those of control. Thiobarbituric acid reactive substances(TBARS) peroxide values(LPO) in liver were increased 2.3-fold in DM group compared with those of control, while LPG in ZDM group was lower than that of DM group, and EDM group had similar tendency compared with that of control. Reduced glutathione(GSH) contents of liver were decreased in DM group compared with those of control, but increased 2.3, 1.7-fold in ZDM and EDM groups, respectively, compared with those of DM group. Oxidized glutathione(GSSG) was increased in DM group compared with control and GSSG in ZDM and EDM group were lower than that of DM group. GSH/GSSG ratio had similar tendency compared with results of GSH. The activities of free radical scavenging enzymes such as superoxide dismutase, glutathione peroxidase and glutathione S-transferase were significantly decreased in DM group compared to those of control, but higher in ZDM and EDM groups than those of DM group. The metallothionein contents in liver and kidney were increased in DM and EDM groups were remarkably increased 20, 5.3-fold in ZDM group, compared with those of control.

당뇨병쥐에 있어서 생체내 항산화방어계에 미치는 zinc투여의 영향을 관찰하기 위하여 비타민 E 투여군과 비교실험하였다. 혈당량은 당뇨군들이 대조군에 비해 현저히 증가되었으나 ZDM군이 DM과 EDM군에 비해 약간 감소되는 경향을 띠었다. 혈장 인슐린수준은 혈당량과 반대의 경향을 띠었다. 간조직중의 TBARS 축적량은 대조군에 비해 DM군은 2.3배 높았고 ZDM군은 DM에 비해 낮아졌으며, EDM군은 대조군과 비슷하였다. 간조직중의 환원형 glutathione(GSH) 함량은 대조군에 비해 DM군은 감소되었으나 ZDM과 EDM군은 DM군에 비해 각각 2.3, 1.7배씩 증가되었다. 산화형 GSH함량은 대조군에 비해 DM군이 증가되었고, DM군에 비해 ZDM군과 EDM군 모두 감소하였으며 GSH/GSSG비는 GSH비와 비슷한 경향이었다. 간조직중의 SOD, GSH-Px, GST활성은 모두 대조군에 비해 DM군은 유의적으로 감소되었으나 ZDM, EDM군은 DM군에 비해 증가되었다. 간장과 신장에서의 metallotruonein 함량은 모두 대조군에 비해 DM, EDM군은 증가하였고, ZDM군은 20배, 5.3배 각각 현저히 증가하였다.

Keywords