Fluoreszenzmethoden zur histochemischen Sichtbarmachung von Monoaminen. 6. Identifizierung der fluoreszierenden Produkte aus m‐Hydroxyphenyläthylaminen und Formaldehyd

It is known that in tissue slices treated with dry gaseous formaldehyde according to the histochemical technique of H ILLARP & F ALCK structures containing catecholamines show a green fluorescence in the fluorescence microscope. The m ‐hydroxyphenylethylamines m ‐tyramine, m ‐hydroxyamphetamine and m ‐hydroxynorephedrine (metaraminol) enclosed in vitro in dry protein films undergo a similar reaction with dry gaseous formaldehyde and form fluorescent products which have been characterized as 6‐hydroxy‐3,4‐dihydro‐isoquinolines existing predominantly in the quinoidal form fluorescing at 385/510 nm. By treatment of these protein layers with gaseous hydrogen chloride another form fluorescing at 360/420 nm can be obtained which is not visible in the fluorescence microscope with the usual equipment.