Effect of Amethopterin on Visceral Concentration of Co 60 B 12 in the Mouse. ∗

Abstract

Summary and conclusion

The effects of 2 doses of amethopterin on hepatic and renal storage and 24-hour uptake of Co⁶⁰B₁₂ were contrasted in the mouse. A nonlethal dose had little effect on these measurements of Co⁶⁰B₁₂ metabolism. Following administration of a lethal dose of amethopterin, a progressive decrease in storage and 24-hour uptake of Co⁶⁰B₁₂ by the liver occurred while concomitant increases were observed in the kidney. It is suggested that the lethal dose of amethopterin was hepatotoxic and decreased the ability of the liver to metabolize Co⁶⁰B₁₂. In such a situation the kidney may become a more important binding site for this vitamin in the mouse.