Atropine and the hyoscyamines—a study of the action of optical isomers

Abstract

(From the Pharmnacological Laboratory of the Univer.sity of Michigan, U.S.A.)THE similarity in the action of belladonna and hvoseyamus preparations has led to a number of researches on the relative power of their active constituents, and Ladenburg's discovery that atropine and hyoscyan-ine are optical isomers has added further interest to the subject. The atropine used by most investigators was crystalline, and probably a fairly pure product, but the so-called " hyoseyamine " appears in the great majority of instances to have been merely a purified extract of hyoseyamus, which certainly' contained hyoscine, and probably atropine and other bodies as well as the alkaloid hyoseyamine. It is scarcely necessary to state that such comparative studies are valueless unless the alkaloids are absolutely pure, and it is accordingly unnecessary to discuss the results of these earlier workers'. Hellmann2 used the hyoscyamine of Reichardct and Hohn, which was less contaminated than the ordinary hyoseyamine of that time, but appears to have been far from pure, and Eckhard', Buchheim4, Harnack5, Hartmann' and Gnauck7 all used the crystalline hyoseyamine prepared by Merck from hyoseyamus. This was undoubtedly an advance in the study of the alkaloids, but the well-known difficulty in isolating hyoscyamine and in preserving it unchanged suggests a doubt as to the purity of the preparations8, and this doubt is confirmed by the numerous contradictory results obtained by these observers.

The action of tubocurarine and atropine on the normal and denervated rat diaphragm

“…That atropine sulphate in high doses paralyses animals had already been observed by Botkin (1862), who ascribed this effect to a peripheral action of the drug which was clearly confirmed in later experiments on isolated nerve-muscle preparations (Cushny, 1903;Haffner, 1914;Riesser & Neuschloss, 1921;Dale & Gaddum, 1930;Abdon, 1945 (Langley, 1905;Dale & Gaddum, 1930;Luco & Sanchez, 1956;Jenkinson, 1960). It is difficult to evaluate the sensitivity to drugs in these experiments: in the denervated muscle a much larger surface of the membrane is sensitive to ACh than in normally innervated fibres.…”

Anisocoria Secondary to Anticholinergic Mydriasis from Homeopathic Pink Eye Relief Drops

“…Hyoscyamine has stronger central and peripheral anticholinergic effects and is more potent in dilating the pupil. 7,8 Therefore, it is possible that pupil dilation from hyoscyamine may last longer than dilation caused by atropine or scopolamine. Our patient stated that she noticed her left pupil was larger than her right one early in the morning; afterwards, she started the Similasan drops.…”

Stereoselective antibodies to free α-hydroxy acids

“…It has been known since the early days of biochemistry that enzymes, receptors and antibodies can discriminate between the stereoisomers of chiral compounds (Fischer, 1894;Cushny, 1904;Landsteiner and van der Scheer, 1928). Numerous examples of differences in the biological activity of stereoisomers have been reported, with nutrients, pesticides and especially drugs being the exogenous compounds most relevant to human health (Holmstedt, 1990;Eliel et al, 1994;Eichelbaum and Gross, 1996;Soundijn et al, 2003).…”