Demonstration of catecholamine and resorcinolamine derivatives as formaldehyde-induced fluorescence in protein models.
We assessed in protein droplet models the potential use of the formaldehyde condensation method for histochemical demonstration of a wide range of catecholamines and resorcinolamines. The experiments showed that all of the amines tested, except salbutamol and carbuterol, formed fluorophores, and that the fluorescence was specific [i.e., there was no fluorescence in the absence of formaldehyde, the fluorescence was quenched by water, and the fluorophores were subject to photodecomposition by the exciting (405-nm) light]. Peak wavelengths of the emission spectra were 480-485 nm for fluorophores of resorcinolamine derivatives. The fluorescence intensity of the catecholamines was greater than that of the resorcinolamines. Fluorophore formation was not hindered by substitution of t-butyl, phenylisoprophyl, or p-hydroxyphenylisopropyl on the amino-N in catecholamines (t-butylnorepinephrine, Cc24, Cc25, respectively) or resorcinolamines (terbutaline, Th1161, fenoterol, respectively), and fluorophores also formed for catecholamines with the amino-N in a ring structure (rimiterol) or with a long alkyl chain substituted on the amino-N (hexoprenaline). Our study showed that fluorescence microphotometry can be used to detect a range of drugs that are catecholamines or resorcinolamines, and hence it should be possible to use this technique to study the properties of dissipation of these amines in tissues.
Bryan
L J
LJ
Department of Physiology and Pharmacology, University of Queensland, Brisbane, Australia.
O'Donnell
S R
SR
D000588:Amines; D002395:Catecholamines; D004983:Ethanolamines; D005557:Formaldehyde; D006651:Histocytochemistry / Q000379:methods*; D008856:Microscopy, Fluorescence; D008956:Models, Chemical; D010777:Photochemistry; D011506:Proteins; D012118:Resorcinols; D013329:Structure-Activity Relationship
D000588:Amines; D002395:Catecholamines; D004983:Ethanolamines; D011506:Proteins; D012118:Resorcinols; D005557:Formaldehyde