title: Evaluation of dopamine metabolism in rat striatum by a gas chromatographic technique.
abstract: Dopamine metabolism in rat striatum was evaluated by gas chromatographic quantitation of 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA). The level of DOPAC (5.21 nmoles/g plus or minus 0.40 S.E.M., n equals 12) exceeded that HVA (3.63 nmoles/g plus or minus 0.25 S.E.M., n equals 12). 2 hr following administration of probenecid (200 mg/kg i.p.) the level of striatal HVA was approximately doubled whereas the level of DOPAC was not significantly elevated. Pargyline (75 mg/kg i.p.) poduced a rapid depletion of DOPAC and HVA. the rate of disappearance of DOPAC (t1/2 equals 10 min) exceeded that of HVA (t1/2 equals 18 min). Rates of metabolite formation were computed assuming steady state kinetics. The rate formation of DOPA (20.5 nmoles/g/hr) was much greater than that of HVA (10.1 nmoles/g/hr). We conclude that DOPAC is the major dopamine metabolite in rat striatum and that its measurement may provide the best index of functional neuronal activity in this species.
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D002849:Chromatography, Gas; D003342:Corpus Striatum / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D006719:Homovanillic Acid / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D008722:Methods; D010293:Pargyline / Q000494:pharmacology; D011339:Probenecid / Q000494:pharmacology; D011422:Propionates / Q000378:metabolism; D051381:Rats
chemical_list: D011422:Propionates; D015102:3,4-Dihydroxyphenylacetic Acid; D010293:Pargyline; D011339:Probenecid; D004298:Dopamine; D006719:Homovanillic Acid