Copper in the Treatment of Molybdenosis in the Rat: Determination of the Dose of the Antidote

Abstract

The relationship between absorption of subcutaneously injected ⁶⁴Cu and copper and molybdenum levels in the diet was studied in an effort to explain some aspects of the problem of the copper-molybdenum interrelationship. A kinetic study of the radioactivity in the blood and liver made it possible to determine the most suitable moment for killing the animals, i.e., 5 hours after the injection. These curves also gave some indication of the role of molybdenum in copper accumulation in the blood and in the lowering of copper metabolism in the liver. Increasing daily doses of molybdenum were tested: 7.62, 14.24, 28.48 and 47.40 mg/rat. These resulted in depressed growth of the animals, and in increased cupremia, copper content of the liver and specific activity of the blood; they lowered the specific activity of the liver up to the dose of 14.24 mg. Therefore a dose of 15 mg of molybdenum was selected for the study of the antidotal effect of copper. This effect was particularly marked with doses ranging between 0.274 and 1 mg of copper. A 1-mg dose caused a rapid increase in the specific activity of the blood and the liver. This 1-mg dose was considered to be the minimal effective quantity for administration, resulting in a 76% recovery of the loss of weight induced by the molybdenum. The best antidotal dose was found to lie between 1 and 4 mg of copper. With higher doses, loss of weight occurred as well as a decrease in the specific activities of blood and liver.