Detection of 3-methoxy-4-hydroxyphenylglycol in rabbit skeletal muscle microdialysate

A high-performance liquid chromatography with electrochemical detection (HPLC–ED) method is described for determination of 3-methoxy-4-hydroxyphenylglycol (MHPG) in microdialysate from the skeletal muscle interstitial space. Using a microdialysis technique, we sampled 30 μl dialysate from the skeletal muscle interstitial space and injected dialysate directly into HPLC–ED system. The control MHPG concentration of dialysate was 213±18 pg/ml. The MHPG concentrations were reduced by entacapone (catechol-O-methyltransferase inhibitor, COMT), augmented by local infusion of dihydroxyphenylglycol. This system offers a new possibility for simple, rapid monitoring of MHPG as an index of COMT activity in skeletal muscle.