Receptor-mediated uptake of hypertriglyceridaemic VLDL remnants by mouse macrophages in vitro

Following incubation of the VLDL isolated from hypertriglyceridaemic patients with normal human postheparin plasma VLDL remnants were obtained. 125I-VLDL remnants were taken up and catabolized by mouse macrophages in vitro. This was a receptor-dependent process. Unlabelled VLDL remnants added to the incubation medium inhibited the degradation of 125I-VLDL remnants in the cells. This could not be produced by the presence of VLDL or acetyl-LDL in the medium. It shows that mouse macrophages bind VLDL remnants by means of an other receptor than that for acetyl-LDL. The cell cholesterol content increased after incubation of the cells with VLDL remnants or acetyl-LDL, but not with native VLDL or LDL.