Experimental and mathematical model for evaluation of LDL uptake by the isolated blood vessels

Abstract

Objective. The aim of this study is to present the experimental model which can be used to determine LDL transport into the blood vessel wall. Method. We used isolated rabbit carotid arteries under physiologically relevant constant pressure and perfusion flow in conditions more similar to in vivo. We used Rapid dual-isotope dilution method, Steady - state method, testing of transport of LDL-before and after removal of the endothelium, in conditions with intact endothelium and after its removal. Results. First we used Rapid dual-isotope dilution method and the data obtained showed that the transport of LDL could not be precisely determined in this way because it was in the range of standard error. Then we used Steady - state method and uptake (Us) was 3.52 ± 1.07% at higher pressure (140±10 mmHg) than at lower pressure (p<0.05). Also, LDL uptake was evaluated before and after the endothelium removal. The results after endothelial removal showed that Us of LDL was almost 3 times higher (9.2%) than with intact endothelium (p<0.05) and that the accumulation of LDL in the blood vessel wall was 0.1% (0.06% in intact endothelium) indicating that intact endothelium was a strong barrier. Conclusion. Our experimental model and applied mathematical procedures can provide a precise description of the LDL uptake by the blood vessel wall.