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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of heavy, long duration aerobic exercise on low density lipoprotein (LDL) susceptibility to oxidation and on distribution of LDL subfractions was studied. Six well-trained runners, previously fasted, ran continuously for 4 h. Controlled intake of liquid and food was permitted during exercise. Total plasma and LDL triglyceride increased significantly. LDL susceptibility to oxidation, measured as conjugated dienes formation, was modified significantly (P < or = 0.05) after running (14% reduction in lag phase time, and 8% increase in maximal curve slope). The percentage of electronegative LDL form (named LDLB) also increased significantly (P < or = 0.05) after exercise both basally (from 7.3% to 11%) and after 2h of induced oxidation (from 40.6% to 52.3%). Neither LDL susceptibility to oxidation nor increase of LDLB was statistically associated with food consumed during the race or modifications of triglycerides suggesting that this effect was due to exercise rather than food-related. The pattern of LDL subfractions was type A in all athletes before and after running. The oxidative LDL changes, seen in exercise conditions similar to those of hard training or competition, demonstrated an unfavourable effect of very intense exercise on lipoprotein metabolism.
Atherosclerosis 1995 Dec
PMID:Increase of LDL susceptibility to oxidation occurring after intense, long duration aerobic exercise. 877 Mar 23

The specific interaction of lipoproteins with arterial wall constituents, particularly proteoglycans (APG), is believed to play an important role in the development of atherosclerosis. The objective of this study was to examine the interaction of apolipoprotein B (apoB) containing lipoprotein subfractions (VLDL1, Sf 60 to 400; VLDL2, Sf 20 to 60; IDL1, Sf 16 to 20; IDL2, Sf 12 to 16; LDLA, Sf 8 to 12; and LDLB, Sf 0 to 8) prepared by cumulative density gradient centrifugation with chondroitin sulfate-rich APG. Eighteen subjects were studied, and a similar pattern of interaction between the lipoprotein species and APG was found in all. The order of reactivity (as measured by increased turbidity due to insoluble complex formation) was IDL Sf 12 to 16 > or = LDL Sf 8 to 12 > LDL Sf 0 to 8 > IDL Sf 16 to 20 >> VLDL Sf 20 to 60 > VLDL Sf 60 to 400. When the subjects were divided on the basis of their LDL subfraction profile, the extent of insoluble complex formation was highest in the group in which small, dense LDLIII was predominant; intermediate in the group whose LDL was mainly LDLII; and lowest in the group with a high proportion of LDLI (the mean reactivity, AU at 600 nm. of APG with IDL Sf 12 to 16 and LDL Sf 8 to 12 was 0.66; 0.62 and 0.46, 0.43 and 0.20, and 0.21 for the three groups, respectively). Fibrate lipid-lowering treatment decreased the percentage of LDLIII and increased the percentage of LDLI within total LDL and reduced the reactivity of all apoB-containing lipoprotein fractions toward APG. Sialic acid content varied in different lipoprotein subfractions, being the highest in VLDL and lowest in LDL. However, across lipoprotein species, it did not significantly correlate with APG-binding reactivity, suggesting that other factors are important in determining the interaction of lipoproteins with APG. Modification of LDL arginine and lysine residues abolished the ability of the lipoprotein to interact with APG, a finding that supports the hypothesis that the interaction is dependent on key positively charged amino acids on apoB. These findings demonstrate that (1) the overall reactivity of apoB-containing lipoproteins is greatest in individuals with small, dense LDL and (2) within an individual, IDL of Sf 12 to 16 is the most reactive species, and this may in part explain the positive correlation between IDL and risk of coronary heart disease.
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PMID:Interaction of very-low-density, intermediate-density, and low-density lipoproteins with human arterial wall proteoglycans. 940 21