Figure 4

The core biochemical network of the ceramide/sphingosine-1-phosphate rheostat. A comprehensive core network is depicted including the possible source of free fatty acids synthesized de novo in the vascular bed (the fatty acid elongation enzyme, ELOV3), as well as the oxidative-redox system (GCLC and GCLM) which regulates neutral sphingomyelinase activity, a source of ceramides. These latter are only introduced as "summary" variables as the focus has been on the de novo pathway of ceramide synthesis. Node degrees are shown in the brackets.