Note
This research was financed by the Harry Ca-rothers Wiess fund of the department of geology of Rice Institute. We thank John M. Whitfield for helping to assemble the collection studied.
November 1957On the Presence of
3-Hydroxytyramine in BrainThe compound 3-hydroxytyramine has attracted interest as a probable intermediate in the biosynthesis of noradrenaline and adrenaline and also as a possible neurohumoral agent. It has been shown to occur in the urine (1), in the adrenals (2, 3), and in the heart (2) of sheep and in the splenic nerve of the ox (4). The study of this compound has been hampered by lack of sensitive and specific assay methods. Apart from bioassay techniques, only the fluorimetric ethylenediamine condensation method of Weil-Malherbe and Bone (5) appears to be sufficiently sensitive for biological purposes. However, with this method the fluorescence spectra obtained from 3-hydroxytyramine and adrenaline are almost identical (6). In the fluorimetric method of Euler and Floding (7), the fluorescence obtained from 3-hydroxytyramine is very weak and amounts to only a few percent of that obtained from noradrenaline or adrenaline.Recently we observed, however, that if the pH of samples prepared essentially according to this method was adjusted to about 5 by means of acetic acid, a fairly strong fluorescence developed. Furthermore, the activation and fluorescence peaks (345 and 410 m,g, respectively, as read in an Aminco-Bowman spectrophotofluorimeter) were at much shorter wavelengths than those obtained from noradrenaline and adrenaline, so that these compounds did not interfere, even if they were present in comparably large amounts.Using this technique in combination with ion-exchange chromatography (Dowex 50), we have started to investi-also possible that early crystallization of plagioclase grains causes them to be isolated from each other by later forming minerals such as quartz and potassium feldspar. Quartz, however, does not seem to affect the development of neighboring grains, and it also appears that no mineral affects the development of other mineral species (1). Note 1. This research was financed by the Harry Carothers Wiess fund of the department of geology of Rice Institute. We thank John M. Whitfield for helping to assemble the collection studied.13 November 1957
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.