Sphingomyelin and Ceramide Mass Assay

As described in Chapter 19 , a demonstration of changes in sphingomyelin (SM) and ceramide cellular contents (in response to regulatory molecules and/or other stimuli) is essential to stablish their involvement in the signaling proccess. The study of variations in SM and ceramide cellular levels, resulting from SMase-mediated SM hydrolysis, may be performed using the method described in Chapter 19 . However, increased levels of ceramide and/or SM may occur under circumstances in which the isotopic labeling method would be inefficient in evaluating the changes (i.e., increased rate of synthesis), or simply impossible to use (i.e., when working with whole tissues or organs). The measurent of sphingomyelin and ceramide mass provides the best solution to these problems.