Effect of Supplementary Copper on Blood and Liver Copper-containing Fractions in Rats

Abstract

Fifty rats were fed rations containing copper, ranging from subnormal levels to toxic amounts, in order to study the influence of dietary copper on the copper-containing fractions of the blood and liver. Copper in the blood was determined as erythrocyte copper and plasma copper. Most of the plasma copper was in the protein ceruloplasmin, and the remainder in a loosely bound form reacting directly with Na diethyldithiocarbamate (DR Cu). Erythrocyte and DR Cu appear to be directly related to the Cu intake with values ranging from 0.95 to 2.04 µg/ml and 0.19 to 1.52 µg/ml, respectively. Ceruloplasmin values were depressed in the low rations (6.6 IU) and remained constant (35 IU) with Cu intakes greater than 10 ppm. In liver of normal rats (ca. 18 ppm Cu) the distribution is: debris, 12.8%; mitochondria, 13.5%; microsomes, 17.9%; and soluble fraction, 54.8%. Liver Cu levels were depressed in the low (1 ppm intake) group (10 ppm), normal in the range of 10 to 100 ppm intake (20 ppm), and elevated with 200 ppm intake (69 ppm). The distribution in the liver fractions was affected by copper content, with the soluble fraction being the most sensitive to changes in liver Cu, and the debris relatively insensitive to the Cu content of the liver.