TY - JOUR T1 - ACIDIC AND NEUTRAL METABOLITES OF NOREPINEPHRINE: THEIR METABOLISM AND TRANSPORT FROM BRAIN JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 457 LP - 462 VL - 181 IS - 3 AU - J. L. MEEK AU - N. H. NEFF Y1 - 1972/06/01 UR - http://jpet.aspetjournals.org/content/181/3/457.abstract N2 - Radiolabeled vanillylmandelic acid, 3-methoxy-4-hydnoxyphenylglycol (MOPEG) and its sulfate conjugate (MOPEG-SO4) were injected into the lateral ventricle of the rat and their metabolic fate was studied. Both vanillylmandelic acid and MOPEG-SO4 were eliminated from brain by a probenecid-sensitive acid transport. A major portion of the injected MOPEG was converted to MOPEG-SO4 and then transported from brain. The transport system for acidic norepinephrine metabolites appeared to be similar to the transport system that rids the brain of homovanillic acid and 5-hydroxyindoleacetic acid. The accumulation of vanillylmandeic acid and MOPEG-SO4 in brain or cerebrospinal fluid after probenecid treatment might be a useful method for studying the synthesis rate of norepinephrine in animals and man. © 1972, by The Williams & Wilkins Co. ER -