Isolation and separation of inositol phosphates from hydrolysates of rat tissues.

I. An electrophoretic method for the rapid separation of the phosphate esters of inositol is presented. 2. It is used, together with ion-exchange chromatography, to establish the presence of inositol diand triphosphates in hydrolysates of trichloroacetic acid residues of rat brain, liver, heart, kidney, and lung. 3. With the aid of a *lP marker, inositol diand triphosphates were also found in hydrolysates of rat erythrocyte stroma. 4. Glycerol diphosphate was found in hydrolysates of rat liver. 5. Inositol tetraphosphate was not found in the hydrolysatesof any of the tissues studied. 6. Residues remaining after extraction of rat brain by established lipid extraction procedures retained substantial amounts of bound inositol diand triphosphates.