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Brain uptake of α‐[ 14 C]methyl‐ para ‐tyrosine in the rat
Author(s) -
Cumming P.,
Venkatachalam T. K.,
Rajagopal S.,
Diksic M.,
Gjedde A.
Publication year - 1994
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/syn.890170208
Subject(s) - striatum , tyrosine , chemistry , tyrosine hydroxylase , homogeneous , in vivo , endocrinology , medicine , biochemistry , biology , dopamine , enzyme , physics , microbiology and biotechnology , thermodynamics
The blood‐brain permeabilities of L‐[ 3 H]tyrosine and the tyrosine hydroxylase (TH) inhibitor β‐[ 14 C]methyl‐ para ‐tyrosine ([ 14 C]AMPT) were determined in rat striatum, a brain region rich in TH activity, and in other brain regions containing relatively little TH activity. In striatum, the unidirectional clearance rate (K 1 ) for L‐[ 3 H]tyrosine (6.2 ml hg‐ −1 min −1 ) was significantly greater than the rates for L‐[ 14 C]AMPT (2.8 ml hg −1 min −1 ) and D‐[ 14 C]AMPT (0.8 ml hg −1 min −1 ). The apparent volume of distribution (V f ) for L‐[ 14 C]AMPT in striatum (72.5 ± 4.0 ml hg‐ 1 ) did not differ from the V f in other brain regions. The homogeneous distribution of L‐[ 14 C]AMPT in rat brain indicates that labeled AMPT is unsuitable for the study of TH in vivo by quantitative autoradiography. © 1994 Wiley‐Liss, Inc.