Starvation and Renal Uptake of Vitamin B₁₂

Abstract

Rosenthal and Cravitz have reported^1–3 that rabbits subjected to starvation accumulated remarkably large amounts of vitamin B₁₂ in the kidney as compared with normally fed controls. They also found similar, but less pronounced, effects of starvation in some animal species. No satisfactory explanation has been offered, however. Our investigations with rats demonstrated that the renal uptake of vitamin B₁₂ labelled with cobalt-60 following an oral administration was much greater in animals which had received vitamin B₁₂ in their diet than in those which had been deprived of it⁴. This finding together with other results⁵ strongly suggest that the kidney is a kind of storage organ of vitamin B₁₂, and that accumulation of the vitamin in this organ is indication of a highly saturated state of the body tissue with respect to vitamin B₁₂. In view of the discrepancy between Rosenthal's and our findings, the starvation experiment described in his recent paper³ was followed, except that a special measure was taken for the prevention of coprophagy.