A METHOD FOR THE DETERMINATION OF BETAINE IN TISSUES USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Betaine is a major metabolite of choline in liver and kidney and may b e an important product of choline metabolism in other tissues. The ava ilable methods for assay of betaine, however, are time consuming and r elatively insensitive. We describe a modification of published methods that provides a sensitive and specific assay for betaine by derivatiz ation and HPLC separation with UV quantitation. Betaine and other wate r-soluble choline metabolites are extracted from biological samples an d separated by HPLC based on mobility of C-14-labeled internal standar ds. The betaine fraction is collected and derivatized with 4'-bromo-ph enacyl triflate. The betaine-triflate derivative is quantitated by UV absorbance and the result is corrected for possible losses due to inco mplete extraction recovery and incomplete derivatization by simultaneo us measurement of radioactivity from the derivatized C-14-betaine infe rnal standard. Betaine concentrations determined with this procedure a re reported for several adult and fetal rat tissues.