Plasma kinetics of a cholesterol-rich microemulsion in patients submitted to heart transplantation.
BACKGROUND
Development of coronary graft disease is currently the main cause of late heart-transplantation (HT) failure. HT patients frequently show hypercholesterolemia as well as alterations in chylomicron metabolism. These postHT changes may be important in coronary graft disease development. To clarify whether hypercholesterolemia is caused by decreased low-density lipoprotein (LDL) removal from the plasma, we studied the plasma kinetics of a cholesterol-rich emulsion that binds to LDL receptor.


METHODS
We studied 13 HT patients and 13 healthy normolipidemic subjects paired for sex, age, and body mass index. An emulsion labeled with C-cholesteryl oleate was injected intravenously, and blood samples were collected in predetermined intervals (5 minutes, 1, 2, 4, 6, and 8 hours) to determine the radioactivity decay curves and to calculate the fractional clearance rates (FCR).


RESULTS
The plasma level of total cholesterol, LDL cholesterol, high-density lipoprotein cholesterol, and apo B were greater in HT group than in the control group (P<0.005). FCR C-cholesteryl oleate was smaller in HT patients when compared with the control group (P=0.02).


CONCLUSIONS
The results showed that HT patients have a deficiency in the mechanisms of LDL removal from the plasma, as tested by the cholesterol-rich emulsion, and this may be important in the development of coronary graft disease.
Puk
Camila G
CG
The Heart Institute (InCor) of the Medical School Hospital, University of São Paulo, CEP 05423-000 São Paulo, SP, Brazil.
Vinagre
Carmen G C
CG
Bocchi
Edmar
E
Bacal
Fernando
F
Stolf
Noedir
N
Maranhão
Raul C
RC
D000328:Adult; D000368:Aged; D001053:Apolipoproteins / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D002250:Carbon Radioisotopes; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood*; D002788:Cholesterol Esters / Q000097:blood; D004655:Emulsions; D005260:Female; D016027:Heart Transplantation; D006801:Humans; D007700:Kinetics; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period
D001053:Apolipoproteins; D001786:Blood Glucose; D002250:Carbon Radioisotopes; D002788:Cholesterol Esters; D004655:Emulsions; D008055:Lipids; C014409:cholesteryl oleate; D002784:Cholesterol