blood low density lipoprotein cholesterol level plasma low density lipoprotein cholesterol level 2011-11-03T03:15:40Z CMO:0000647 Measurement of the amount of cholesterol, a eukaryotic sterol that in higher animals is the precursor of bile acids and steroid hormones and a key constituent of cell membranes, carried in low-density lipoprotein (LDL) molecules in a specified volume of plasma, the fibrinogen-containing fluid portion of the blood in which the particulate components are suspended. LDL constitute a class of relatively large, heterogeneous lipoprotein particles, complex molecules that consist of a protein membrane surrounding a core of lipids. The LDL class of lipoproteins has a density between 1.019 and 1.063 g/ml. In some animal species, such as canine and rodents, this may overlap with the HDL1 class and be designated LDL/HDL1. VT:0000181 Values for density ranges of the lipoprotein classes are approximate. The classes may be defined differently by different researchers, in part because class definitions depend on the number of subclasses into which the lipoprotein fractions are divided. clinical_measurement_ontology mshimoyama plasma LDL level plasma LDL-C level plasma cholesterol level