THE DISTRIBUTION OF VANADIUM AND SULFUR IN THE BLOOD-CELLS, AND THE NATURE OF VANADIUM IN THE BLOOD-CELLS AND PLASMA OF THE ASCIDIAN, ASCIDIA-CERATODES

Blood cells: 1. At least three blood cell types contain vanadium and sulfur: morula, compartment, and pigment cells. 2. The S contents of the pigment and morula cells are nearly the same, but less than that of the compartment cells; while the V contents of the pigment and compartment cells are nearly the same, but greater than that of the morula cells. 3. S/V ratios suggest an ontological relation between compartment and morula cells, if the change in cell type only involves a dilution or concentration of the S- and V-containing constituents. 4. Vanadium (III) in the blood cells is partly present as the dimer VOV4+, but the dimer is not found in the V(IV)- containing aplousobranch ascidian Ciona intestinalis or the low V-containing stolidobranch ascidian Pyura haustor. Plasma: 1. Vanadium(V) is present in the blood plasma at 0.01-0.06 mM. 2. The form of V(V) in the plasma is different than in seawater at the same concentration. 3. Vanadium(V) levels in the plasma appear to be regulated.