Abstract
Microdialysis was used to estimate in vivo tyrosine hydroxylase (TH) activity in locus coeruleus (LC) of conscious rats. An aromatic amino acid decarboxylase inhibitor, difluoromethyl-DOPA (DFMD), was perfused through the dialysis probe and the DOPA accumulating in dialysates was measured. A 3 h perfusion of a 6 × 10 −4 mol/ l DFMD solution was needed to obtain measurable levels of DOPA in LC dialy sates: a linear increase in DOPA concentrations was first observed and, then, a steady state. DOPA disappeared completely after inhibition of TH by α-methyl-p-tyrosine, showing that it reflects TH activity. The DFMD perfusion needed in this study was six times higher in concentration and three times longer in duration than the one required in a previous study we performed in LC of anesthetized rats. Furthermore, TH activity was found lower than the one we previously reported. We conclude that these differences could be explained by the effects of halothane anesthesia on DFMD and DOPA degradation and/or on LC neurons TH activity itself.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.