Determination of bovine serum low-density lipoprotein cholesterol using the N-geneous method.

The N-geneous method is a recently developed method for determination of low-density lipoprotein cholesterol (LDL-C) in human serum. In the present study, we attempted to adapt this method to bovine serum. The values of LDL-C obtained using the N-geneous method were highly correlated with those from the method using ultracentrifugation and heparin sepharose affinity chromatography (r = 0.934, p < 0.001). The reproducibility of this method was acceptable (intra-assay CV 4.2%, inter-assay CV 7.6%) for clinical use. Using the N-geneous method, serum LDL-C was evaluated in cows around parturition, and in cows with fatty liver induced by fasting. The concentration of LDL-C decreased significantly in cows close to parturition. A reduced concentration of LDL-C was also observed in cows with fatty liver. In both cases, the changes of LDL-C were similar to those of apolipoprotein B (apoB)-100, and the values of LDL-C were highly correlated (r = 0.876, p < 0.001) with those of apoB-100. These results suggest that the concentration of LDL-C reflects the level of apoB-100. The N-geneous method is simple and rapid, and might to be a useful tool to elucidate the clinical significance of LDL-C in bovine serum.