| Popis: |
31p nuclear magnetic resonance (NMR) spectroscopy can now uniquely provide a real-time panoramic view of the major intracellular phosphate metabolites and their concentrations in living cells/tissues. Hormone regulated cascades in many instances influence intracellular phosphate metabolism. This influence is apparent mainly at two levels: (1) cellular energy, i.e., modulation of ATP synthesis and utilization, and (2) cellular control mechanisms where regulation of key enzymes is often mediated by second messengers, themselves phosphate metabolites, such as 3′5′ cyclic adenosine monophosphate (cAMP), 3′5′ cyclic guanosine monophosphate (cGMP), inositol tris phosphate (IP3) and/or by protein phosphorylation/dephosphorylation reactions. Certain aspects of energy-related phosphate metabolism have been previously reported in the literature. We were thus prompted to apply this non-invasive technique, to examination of signal transducing processes and the responsive cascades regulated by the melanocyte stimulating hormone (MSH) in live cultured M2R mouse melanoma cells. We describe here two major observations that were made in the course of these studies. (1) The discovery of a novel phospholipid associated pathway stimulated by MSH that leads to phosphoethanolamine (PE) production, and (2) that MSH stimulated synthesis of cAMP and a concomitant adenylate cyclase (AC) dependent depletion of ATP in these cells can be simultaneously monitored by 31P NMR spectroscopy. |
