Fasting Whole-Body Energy Homeostasis and Hepatic Energy Metabolism in Nondiabetic Humans with Fatty Liver

Figure 1

A typical ³¹P spectrum of a normal subject is depicted in (a). In (b), the spectrum after line-fitting procedures is shown. The signals that can be detected are the signals of the three phosphorous atoms of adenosine triphosphates (γ, α, and β). Phosphomonoesters (PME), inorganic phosphorous (Pi), and phosphodiesters (PDE) are detectable at ppm on the left side of the spectrum. PMEs (phosphocholine, phosphoethanolamine, adenosine monophosphate, and glycolytic intermediates including glucose-6-phosphate) and PDEs (glycerolphosphorylcholine and glycerolphosphorylethanolamine) represent a heterogeneous mix of compounds that share only a similar chemical feature but otherwise have diverse chemical structures and functions. Pi signal corresponds to free inorganic phosphorous. In contrast with the skeletal muscle and the heart, very little, if any, phosphocreatine is detectable in the liver (chemical shift at 0 ppm); its presence in the spectrum is likely a marker of extrahepatic muscle contamination from malpositioning of the spectroscopic voxel.

(a)

(b)