Methods

An enzymatic method is described for the measurement of vanillyl mandelic acid (VMA). The method utilizes an L-mandelic acid dehydrogenase preparation from Pseudomonas fluorescens A-312 to catalyze the transformation of VMA to vanillin. The method is specific for VMA becauseonly the final product, vanillin, will absorb maximally at 350 m/L. The results compare favorably with the method of Pisanoeta!. (2). CATECHOLAMINES are excreted in the urine both unchanged and after degradation to vanillyl mandelic acid (VMA) and other derivatives. Since the concentration of VMA in the urine of normal subjects is ap-proximately 5 times that of the undegraded catecholamines (1), the urinary level of VMA is an excellent indicator of epinephrine and norepinephrine production. We have developed a method for measuring VMA in the urine which entails the use of an L-mandelic acid dehydrogenase enzyme prepara-tion isolatd from Pseudornonas fluorescens A-312. This method is as specific as the method of Pisano et al. (2) and is much less cumber-some