The sphingolipid composition of bovine kidney cortex, medulla and papilla.

Abstract 1. 1. The major sphingolipids of bovine kidney cortex, medulla and papilla were prepared, weighed and characterized. Each of these regions had its own sphingolipid pattern. 2. 2. Sphingomyelins were the major sphingolipid class of bovine kidney. Their concentration decreased from cortex to papilla. 3. 3. Free ceramides were present in considerable amounts. They also decreased in concentration from cortex to papilla. 4. 4. The main glycosphingolipids were glucosylceramides, galactosylceramides and galactosylceramide sulphate esters (sulphatides). Diglycosylceramides and triglycosylceramides were smaller fractions, and tetraglycosylceramides were not detected. Gangliosides were not isolated. 5. 5. Galactosylceramides and sulphatides were concentrated in the medulla, while the cortex and papilla had lower concentrations. 6. 6. The level of glucosylceramides was approximately the same in the cortex as in the medulla, but it was much higher in the papilla. 7. 7. Diglycosylceramides and triglycosylceramides, measured together, increased gradually from cortex to papilla. In the cortex their ratio was about 1: 2, in the medulla 1:1, and in the papilla 3:2. 8. 8. A simple thin-layer Chromatographie study on the phospholipid patterns of the cortex and medulla revealed no differences in relative amounts. 9. 9. The (Na + -K + -ATPase, determined as ouabain-sensitive ATPase, had about the same activity in the cortex as in the medulla.