Determination of the response of melanoma cells to melanocyte stimulating hormone by 31P nuclear magnetic resonance spectroscopy.

Using living cells or tissues 31P nuclear magnetic resonance (NMR) spectroscopy can uniquely provide a real-time panoramic view of the major intracellular phosphate metabolites and continuously monitor changes in their concentrations. Hormone regulated cascades in many instances influence intracellular phosphate metabolism at various levels. Regulation of the respective key control enzymes is often mediated by second messengers, themselves phosphate metabolites, such as 3'5' cyclic adenosine monophosphate (cAMP), 3'5' cyclic guanosine monophosphate (cGMP), and inositol Tris phosphate (IP3). Moreover, protein phosphorylation/dephosphorylation reactions are also extensively involved in hormonal regulation. The consequent changes in the rates of the regulated processes, best known in the cases of glycogen and fat metabolism, are reflected in the rates of ATP synthesis and utilization as well as in the levels of phosphate containing intermediary metabolites. In this paper we describe an application of non-invasive 31P NMR spectroscopy for the examination of a signal transducing process and responsive cascades regulated by the melanocyte stimulating hormone (MSH) in live cultured M2R mouse melanoma cells. With proper modifications this technical approach can be adapted to the study of other cell systems.