Resumo

SCOCCIA, Adriana Elena  e  MOLINUEVO, María Silvina. Low-density lipoproteins (LDL) are circulating inhibitors of the pro-coagulant activity of tissue factor. Acta bioquím. clín. latinoam. [online]. 2006, vol.40, n.1, pp.63-69. ISSN 0325-2957.

The objective of the present work was to explore the electrophoretic mobility of the involved proteins and the kinetic of pro - coagulant activity inhibition, that allow us to propose a quantitative in vitro assay of potential clinical use. For the kinetic assay, commercial calcic thromboplastine was incubated with increasing volumes of redisolved - selectively precipitated LDL at 37 ºC. Then the prothrombine time in one step was made; the inhibitory activity and percentage of inhibition against a blank were calculated. The results show an increasing inhibition of pro-coagulant activity until 60 min between 0.013 - 0.026 nmol apoB. The conditions for the assay of 30 samples of normolipemic individuals (ages between 30 - 70 years old) were selected on the basis of these results. The assay of % coagulation inhibition / nmol apoB showed signficative differences for control group versus diabetic one. The protein electrophoresis showed two bands in pre-beta and beta positions corresponding to thromboplastine and LDL respectively at time zero. After 60 min of incubation one intense band corresponding to LDL - tissue factor complex can be observed. This work proposes a simple assay for the evaluation of LDL role in haemostatic control in pathological conditions, although further clinical assays are still required.

Palavras-chave : tissue factor; thromboplastine; factor III; low density lipoproteins; pro-coagulant activity inhibition; diabetes.

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