Association of prothrombin and protein S with plasma triglyceride-rich lipoproteins in humans after test meals rich in milk fat or soybean oil.
BACKGROUND
Prothrombin can associate with rat chylomicrons in vitro. This enhances a platelet factor Xa mediated prothrombin activation when the chylomicron-prothrombin complex is exposed to platelets. Vitamin K-dependent pro- and anti-coagulation proteins are associated with TG-rich lipoproteins obtained from human plasma. In the present study, we examined the effects of saturated and unsaturated fat meals on the association of prothrombin and protein S with TG-rich lipoproteins in vivo.


METHODS
Human EDTA plasma was separated from normal subjects after overnight fasting and 2.5 h after ingestion of either a saturated fat meal (butter and cream) or an unsaturated fat meal (soybean oil) containing 54-80 g fat (60.2 E%). The prothrombin and protein S in delipidated lipoproteins were determined by SDS-PAGE combined with Western blotting.


RESULTS
Both prothrombin and protein S associated with TG-rich lipoproteins in fasting and in postprandial samples. The levels of prothrombin and protein S in postprandial TG-rich lipoproteins, especially after ingestion of a saturated fat meal, were higher than those in fasting TG-rich lipoproteins.


CONCLUSIONS
The levels of both prothrombin and protein S in TG-rich lipoproteins in plasma increased after a single fat meal. This association is more pronounced after saturated fat meals and one may hypothesize that it can be linked to atherogenic properties of TG-rich lipoproteins.
Zhou
Li
L
Gastroenterology Division, Department of Medicine, Lund University, Tornavägen, Sweden. li.zhou@med.lu.se
Xu
Ning
N
Nilsson
Ake
A
D000328:Adult; D015153:Blotting, Western; D004041:Dietary Fats / Q000008:administration & dosage*; D004591:Electrophoresis, Polyacrylamide Gel; D005215:Fasting / Q000097:blood; D005260:Female; D006801:Humans; D008055:Lipids / Q000097:blood; D008074:Lipoproteins / Q000097:blood* / Q000737:chemistry; D008297:Male; D019518:Postprandial Period / Q000502:physiology; D017293:Protein S / Q000032:analysis*; D011516:Prothrombin / Q000032:analysis*; D013024:Soybean Oil / Q000008:administration & dosage*; D014280:Triglycerides / Q000097:blood*
D004041:Dietary Fats; D008055:Lipids; D008074:Lipoproteins; D017293:Protein S; D014280:Triglycerides; D013024:Soybean Oil; D011516:Prothrombin