PMID- 16934236
OWN - NLM
STAT- MEDLINE
DCOM- 20061204
LR  - 20131121
IS  - 0006-8993 (Print)
IS  - 0006-8993 (Linking)
VI  - 1115
IP  - 1
DP  - 2006 Oct 18
TI  - Increased striatal dopamine synthesis is associated with decreased tissue levels 
      of tyrosine.
PG  - 26-36
AB  - Tyrosine levels do not generally affect indices of dopamine (DA) synthesis or 
      efflux under basal conditions, but can do so when DA synthesis is increased. One 
      possibility is that a high rate of DA synthesis depletes the normally adequate 
      pool of endogenous tyrosine. To study this, we administered drugs known to 
      preferentially increase striatal DA synthesis and examined DOPA levels in 
      striatal microdialysate during perfusion with NSD-1015. In additional groups, we 
      also measured DA, tyrosine and large neutral amino acids in striatal 
      microdialysate, as well as in tissue from striatum and medial prefrontal cortex 
      (MPFC). gamma-butyrolactone (GBL) (750 mg/kg i.p.) increased DOPA levels in 
      striatal microdialysate, increased tissue DA levels in the MPFC and striatum, but 
      lowered tissue tyrosine levels only in striatum. In striatal microdialysate, GBL 
      markedly lowered DA levels; tyrosine levels were only marginally lower. 
      Haloperidol (HAL) (1.0 mg/kg s.c.)+/-amfonelic acid (AFA) (5 mg/kg i.p.) 
      increased striatal DOPA accumulation, increased striatal DA efflux, lowered 
      striatal tissue tyrosine levels, but did not affect microdialysate tyrosine 
      levels. There were no consistent changes in levels of other large neutral amino 
      acids. We conclude that increased tyrosine hydroxylation can significantly 
      deplete the endogenous pool of tyrosine. Under such conditions, near normal 
      extracellular tyrosine levels are maintained despite lower tissue levels. The 
      data are consistent with a net transfer of tyrosine from non-DAergic cells to DA 
      terminals in support of DA synthesis.
FAU - Bongiovanni, Rodolfo
AU  - Bongiovanni R
AD  - Psychiatry Service, Louis Stokes Department of Veterans Affairs Medical Center, 
      Cleveland, OH 44141, USA.
FAU - Young, Damon
AU  - Young D
FAU - Newbould, Erica
AU  - Newbould E
FAU - Jaskiw, George E
AU  - Jaskiw GE
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20060824
PL  - Netherlands
TA  - Brain Res
JT  - Brain research
JID - 0045503
RN  - 0 (Amino Acids)
RN  - 0 (Dopamine Antagonists)
RN  - 0 (Solvents)
RN  - 42HK56048U (Tyrosine)
RN  - 63-84-3 (Dihydroxyphenylalanine)
RN  - EC 1.14.16.2 (Tyrosine 3-Monooxygenase)
RN  - J6292F8L3D (Haloperidol)
RN  - OL659KIY4X (4-Butyrolactone)
RN  - VTD58H1Z2X (Dopamine)
SB  - IM
MH  - 4-Butyrolactone/pharmacology
MH  - Amino Acids/analysis/metabolism
MH  - Animals
MH  - Corpus Striatum/drug effects/*metabolism
MH  - Dihydroxyphenylalanine/analysis/metabolism
MH  - Dopamine/*biosynthesis
MH  - Dopamine Antagonists/pharmacology
MH  - Down-Regulation/drug effects/physiology
MH  - Extracellular Fluid/drug effects/metabolism
MH  - Haloperidol/pharmacology
MH  - Hydroxylation/drug effects
MH  - Male
MH  - Microdialysis
MH  - Neurons/drug effects/metabolism
MH  - Prefrontal Cortex/drug effects/metabolism
MH  - Presynaptic Terminals/drug effects/metabolism
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Solvents
MH  - Tyrosine/*metabolism
MH  - Tyrosine 3-Monooxygenase/*metabolism
MH  - Up-Regulation/drug effects/physiology
EDAT- 2006/08/29 09:00
MHDA- 2006/12/09 09:00
CRDT- 2006/08/29 09:00
PHST- 2006/04/11 00:00 [received]
PHST- 2006/07/20 00:00 [revised]
PHST- 2006/07/24 00:00 [accepted]
PHST- 2006/08/29 09:00 [pubmed]
PHST- 2006/12/09 09:00 [medline]
PHST- 2006/08/29 09:00 [entrez]
AID - S0006-8993(06)02217-7 [pii]
AID - 10.1016/j.brainres.2006.07.074 [doi]
PST - ppublish
SO  - Brain Res. 2006 Oct 18;1115(1):26-36. doi: 10.1016/j.brainres.2006.07.074. Epub 
      2006 Aug 24.