1997 Fiscal Year Final Research Report Summary
EFFECT OF SURFACE STATE ON LIPOLYSIS OF LIPID EMULSIONS
| Project/Area Number |
07457528
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical pharmacy
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
HANDA Tetsurou FACULTY OF PHARMACEUTICAL SCIENCES,KYOTO UNIVERSITY PROFESSOR, 薬学研究科, 教授 (00025719)
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| Project Period (FY) |
1995 – 1997
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| Keywords | EMULSIONS / LIPOLYSIS / LIPOPROTEIN LIPASE / APOLIPOPROTEINS / LECITHIN / SPHINGOMYELIN / TRIACYLGLYCERIDE / CHOLESTEROL |
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| Research Abstract |
Triacylglyceride (TG)/lechitin (PC)-emulsions are protein-free models for TG-rich plasma lipoproteins (chylomicrons and very low density lipoproteins). These lipid emulsions have been utilized as high caloric nutrition and drug delivery systems. During the lipoprotein metabolism, lipid composition of lipoprotein particles changes by lipolysis and lipid transfer in plasma. The lipid composition is assumed to be an important factor in determination of metabolic fates of lipoproteins. In this study, TG-lipolysis and receptor-mediated hepatic uptake of emulsions are studied in terms of plasma apolipoprotein and lipoprotein lipase (LPL) binding to the lipid particles, and of interaction between amphiphilic helices of proteins and surface layrs of lipid particles with different composition.
Results of this project :
1.Binding amounts of apoC-2 and apoE to PC/TG-emulsions were much larger than those to PC-vesicles in plasma. Accordingly, the hepatic uptake of emulsions through apoE receptors was more rapid than vesicles in rat. The maximum binding amount of the isolated apoA-1 was also much larger for emulsions than vesicles.
2.Apolipoproteins were though to interact surface PC layrs of lipid particles, with the amphiphilic helices nestled between the PC head groups. The different binding capacities between different emulsions and vesicles are explained by the interaction of surface and core lipids.
3.Cholesterol and sphingomyelin influenced the hydration state of emulsion surface, and led to activation of apoE and inhibition of lipolysis by LPL,respectively.
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