Life span of thrombocytes and erythrocytes in normal and thrombocytopenic calves.

By N. S. MIZUNO, V. PEnMAN, F. W. BATES, J. H. SAU’rTER AND M. 0. SCHULrLE SEVERE HYPOPLASIA of the bone marrow,1’2 including any desired degree of thrombocytopenia,3 can be induced in the bovine by feeding of appropriate amounts of trichloroethylene-extracted soybean oil meal ( TCESOM). This affords a unique opportunity for analytic study of thrombocytes from thrombocytopenic animals in which this condition might be the result of decreased rate of formation or a decreased life span of the thrombocytes or of both factors. The life span of human erythrocytes4 and thrombocytes5 has been estimated recently by labeling them in vivo with radioactive diisopropylphosphorofluoridate ( DFP32 ) . This compound combines with esterase enzymes, the presence of which has been demonstrated in bovine erythrocytes6 and thrombocytes.7’8 This study was undertaken to determine whether bovine thrombocytes and erythrocytes could be labeled in vivo with DFP32, and to establish whether the life span of these cells was changed in calves with hypoplastic bone marrow.