Changes in Distribution of α-Tocopherol and Cholesterol in Serum Lipoproteins and Tissues of Rats by Dietary PCB and Dietary Level of Protein

Abstract

An experiment was conducted with growing rats to examine the influence of dietary addition of 0.1% polychlorinated biphenyls (PCB) and dietary level of protein on the distributions of α-tocopherol and cholesterol in serum lipoproteins and tissues. Addition of PCB increased serum α-tocopherol. This was mainly due to the increment in the fractions of chylomicrons/very-low-density lipoproteins (VLDL) and high-density lipoproteins (HDL). This chemical also increased serum cholesterol and HDL cholesterol. The contents of α-tocopherol and cholesterol in HDL fraction were higher in the high protein groups as compared to the low protein groups, regardless of PCB intake. PCB intake increased the concentrations of α-tocopherol in tissues including spleen, lung, kidney, testis, muscle, adipose tissue, and brain. High protein diet increased the levels of α-tocopherol in these tissues as compared to low protein diet. PCB intake also increased adrenal α-tocopherol, which was potentiated with low protein diet. The increment in liver α-tocopherol by PCB intake was observed only in the animals fed on low protein diet.