Abstract
The presence of adrenaline in the mammalian central nervous system has long been recognized 2,12. A first attempt to study the regional distribution in the brain was made by Vogt 11 using a bioassay in combination with a paper chromatographic separation. Vogt's conclusion, that the adrenaline concentration in the brain is low relative to that of noradrenaline, was later substantiated by many authors using spectrofluorometric assay methods (for review, see ref. 3). However, these spectrofluorometric methods are not sensitive enough to enable the measurement of adrenaline in small brain regions, unless tissues of many animals are pooled 5. Although the histochemical fluorescence method for the visualization of catecholamines is more sensitive, it lacks the specificity for the discrimination between adrenaline and noradrenaline. Biochemical 9 and immunohistochemical 4 studies have indicated that phenylethanolamine-N-methyltransferase (PNMT), the enzyme which catalyzes the conversion of noradrenaline into adrenaline, shows a distinct regional distribution in the brain. Such findings support the contention that adrenaline may act as a transmitter in certain regions of the central nervous system. Recently, Koslow and Schlumpf 6, using a gas chromatographic-mass spectrometric technique, were able to detect adrenaline in 5 rat brain regions out of the 15 which were investigated. In this communication we present data, obtained with a radiometric method for the simultaneous assay of adrenaline, noradrenaline and dopamine in combination with a micropunch technique for the removal of rat brain nuclei s, indicating that adrenaline is unevenly distributed in rat brain and that, in general, this distribution is consistent with that of PNMT4, 9. The data on noradrenaline and dopamine concentrations will be presented in a separate paper 10. Male rats weighing 180-220 g were used. The animals were killed by decapitation. The brains were rapidly taken out and frozen on dry ice. Serial sections of 300 gm were cut in a cryostat at -10 °C. Individual brain regions were removed with small punches s. Tissue pellets of similar regions of three rats were pooled. Ninety two
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
