Interaction of cyclosporin A with human lipoproteins.
The ultracentrifugal fractionation of human serum after previous incubation with cyclosporin A showed that, in healthy fasting individuals, 8% of cyclosporin A was found in the very low density lipoproteins (VLDL), 31% in the low density lipoproteins (LDL), 46% in the high density lipoproteins (HDL) and 15% in the non-lipoprotein protein fraction. In non-fasted, healthy and in non-fasted, lipaemic individuals, 7 and 6% of cyclosporin A was found in chylomicrons, 9 and 13% in VLDL, 28 and 30% in LDL, 39 and 37% in HDL, and 12 and 13% in the non-lipoprotein protein fraction, respectively. In patients receiving cyclosporin A the distribution varied from 12 to 19% in VLDL, 21 to 28% in LDL, 33 to 43% in HDL, and 13 to 20% in non-lipoprotein proteins. The interaction between cyclosporin A and isolated normal human lipoproteins was also studied by ultrafiltration. All lipoproteins exhibited a non-saturable, low affinity, high capacity uptake for cyclosporin A. Analysis of the uptake by phospholipid vesicles showed a similar uptake, suggesting that cyclosporin A dissolves in the lipophilic portion of the lipoprotein molecule rather than being associated with specific binding sites.
D003524:Cyclosporins / Q000097:blood*; D005215:Fasting; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood; D008074:Lipoproteins / Q000097:blood*; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D008079:Lipoproteins, VLDL / Q000097:blood; D008081:Liposomes; D011485:Protein Binding
D003524:Cyclosporins; D008074:Lipoproteins; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D008081:Liposomes