31P NMR spectra of intact red blood cells: quantitation of UDPGlucose and UDPGalactose.

The combined levels of uridine diphosphogalactose (UDPGal) and uridine diphosphoglucose (UDPGlu) were measured directly by 31P NMR spectroscopy in intact fully oxygenated erythrocytes. Quantitative analysis was obtained using a sealed capillary of methylene diphosphonate (MDP) calibrated with standard solutions of UDPGlu and UDPGal of known concentration prepared in KRB/BSA. The combined peaks of UDPGlu and UDPGal were integrated after subtraction of the underlying broad component originating from membrane phospholipids. The average concentration of 27.16 +/- 5.18 nmole/ml or 8.08 +/- 1.36 mumole/100 g hemoglobin obtained for these metabolites correlated well with their total determined by HPLC of trichloracetic acid (TCA) extracts of the same samples.