Effects of noradrenergic neuronal activity on 3,4-dihydroxyphenylethylene glycol (DHPG) levels. Quantitation by high...

We describe a sensitive specific and simple high pressure liquid chromatographic procedure for determining 3,4-dihydroxyphenyl-ethylene glycol (DHPG) in both plasma and tissue. DHPG is extracted from plasma or tissue extracts by adsorption onto alumina. DHPG in the alumina eluate is detected electrochemically following chromatography on a C18 reverse phase column. The method is sensitive enough to detect approximately 20 pg/ml of plasma DHPG. Both clonidine (100 micrograms/kg) and desmethylimipramine (2.5 mg/kg) when administered to rabbits for 3 days induced significant falls in both cardiac and plasma DHPG concentrations. These experiments indicate that both tissue and plasma DHPG concentrations may be of value in assessing both the release and re-uptake of norepinephrine at peripheral sympathetic nerve endings in vivo.