Fatty Acid Composition and Functional Properties of Low Density Lipoprotein and Oxidized LDL from Human Plasma

인체 혈장에서 분리한 LDL과 LDL의 지방산 조성과 기능성의 변화

  • Jae-Hoon Choi (Dept. of Biochemistry, Kangwon National University) ;
  • Hyun-Mi Cho (Dept. of Biochemistry, Kangwon National University) ;
  • Heung-Soo Son (Korea Nutrition Institute, Hallym University) ;
  • Tae-Woong Kim (Dept. of Biochemistry, Kangwon National University)
  • Published : 1994.06.01

Abstract

Human plasma low density lipoprotein (LDL) is the major factor of coronary heart disease.But recent studies suggest the normal LDL can be realdily oxidized by oxygen free radicals and not interact with LDL receptors.Lipoprotei particles consist of lipid and protein, and fatty acids are prone to oxidatioin.The fatty acid compositions of LDL from Koreans was compared with that of Westerners.From the results, the raio of unsaturated fatty acids of korean and Westerner approximately 30 and 70%, respectively.which means Westerners are more labile in the lipid oxidation of LDL than Koreams.Normal LDL was incubated with $CuSO_4$ in PBS to lead for the peroxidation of LDL, and it was tested by the detection of TBARS and free radicals.Then, ascorbate, ${\alpha}-tocopherol$ and hyaluronic acid were found to have effects of antioxidants on LDL oxidation.The amount of free radical increased as the extent of oxidation increased.The time course of free radical formation was similar to TBARS.Therefore, determination of free radical by Luminometer was much more convenient than that of TBARS.

인체의 혈장 저밀도 지단백(LDL)은 관상동맥경화 발병의 주 요인이다. 그러나 최근의 연구들은, 정상적인 LDL은 산소 자류라디칼에 의해 쉽게 산화되며, 결과 LDL 수용채와 결합하지 못한다고 밝히고 있다. 따라서 이 변형된 형태의 산화된 LDL은 macrophage scavernger receptor에 의해 인식되어 foam cell을 형성하여, 동맥혈관이 좁아지는 역할을 수행한다고 알려지고 있다. 지리과 산화에는 지방산이 중요한 작용을 하므로, 한국인의 LDL의 지방산 조성을 분석하여 서양인과 비교하였다. 결과, 한국인의 불포화 지방산의 비율이 총 지방산 함량의 약 30%인 반면 서양인은 약 70%의 분포를 갖고 있는 것으로 발표되었다. 따라서 한국인이 서양인에 비해 LDL의 산화에 대한 영향을 적게 받을 수 있으며, 따라서 동맥경화나 심장병의 발생률이 훨씬 적을 것으로 결론을 내릴 있다. 정상적인 LDL을 황산구리와 함께 배양하여, 지방의 산화를 유도하였으며 이의 정도를 지방산 산화의 생성물인 TBARS를 측정하여, LDL이 산화될 때 생성되는 자유라디칼의 양을 측정하므로서 비교하였다. 이 때, 항상화제인 비타민 C; 비타민 E와 히알우로닉산을 첨가하면 LDL의 산화가 억제되는 효과를 확인하였다. 자유 라디탈이 증가함에 따라 산화의 정도도 증가하였으며, 자유라디칼 형성의 경시적 변화는 TBARS와 유사하였다. 따라서 luminometer에 의한 자유라디칼의 정량은 TBARS에 의한 것보다 훨씬 간편한 것으로 나타났다.

Keywords

References

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