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Apparent turnover of norepinephrine in the intact rat brain estimated from its rate of appearance in the cerebroventricular compartment
Author(s) -
Levitt Morton,
Kowalik S.,
Barkai A. I.
Publication year - 1983
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.490100111
Subject(s) - tranylcypromine , norepinephrine , compartment (ship) , endogeny , chemistry , endocrinology , medicine , perfusion , in vivo , monoamine oxidase , biology , biochemistry , enzyme , dopamine , oceanography , microbiology and biotechnology , geology
The apparent turnover of norepinephrine (NE) in the intact brain of urethane‐anesthetized rats was estimated in vivo from the rate of appearance of endogenous NE in the cerebroventricular compartment. Ventriculocibternal perfusion, a radioenzymatic assay for endogenous NE and isotope dilution of 3 H‐NE were used to determine the rate of appearance (R a ) of NE. The effect of tranylcypromine, a monoainine oxidase (MAO) inhibitor and releasing agent on R a of NE, was also studied. In control animals, the mean R a value was 0.40 pmol/min. Pretreatment with tranylcypromine resulted in a threefold increase in the mean value for R a , which was due to increased secretion of NE into the CSF. The results indicate that 90% of the NE entering the cerehroventricular compartment was removed. Pretreatment with tranylcypromine did not modify removal, thus suggesting that tranylcypromine has no effect on the physiological processes which regulate the removal of NE from the CSF.