Showing papers on "Theobromine published in 1973"
TL;DR: Results support the view that theobromine is the immediate precursor of caffeine and the role of gamma-glutamylmethylamide in methylamine metabolism in tea plants is discussed.
Abstract: 1. The metabolism of methylamine in excised shoot tips of tea was studied with micromolar amounts of [14C]methylamine. Of the [14C]methylamine supplied 57% was utilized by tea shoots during the 10h experimental period. 2. The main products of [14C]methylamine metabolism in tea shoots were serine, γ-glutamylmethylamide, theobromine, caffeine and CO2. There was also incorporation of the label into glutamate, aspartate, RNA purine nucleotides and S-adenosylmethionine. 3. The formation of methylamine from γ-glutamylmethylamide was confirmed by feeding tea shoots with γ-glutamyl[14C]methylamide. The products of γ-glutamyl[14C]methylamide metabolism in tea plants were serine, theobromine, caffeine, glutamate and aspartate. 4. The results indicate that the oxidation of methylamine to formaldehyde is the first step of methylamine utilization. Labelled formaldehyde released by the metabolism of methylamine leads to the incorporation of the label into metabolites on the C1 pathways of this compound. It is also suggested that formaldehyde is further oxidized via formate to CO2. 5. The role of γ-glutamylmethylamide in methylamine metabolism in tea plants is discussed. 6. Results support the view that theobromine is the immediate precursor of caffeine.
26 citations
TL;DR: Two other methyl xanthines, theophylline and theobromine have a similar effect on rat fetuses when the mothers are given same under similar conditions as was caffeine.
16 citations
TL;DR: Evidence is presented that 3-methylxanthine and 7-methyl Xanthine are metabolites from theophylline and theobromine, occurring in stimulants such as tea and chocolate; 1-methylXanthine probably originates from coffee.
14 citations
TL;DR: Theophylline and caffeine either inhibited or potentiated the noradrenaline constrictor response in an isolated perfused mesenteric artery preparation and theobromine produced only inhibition of the nor adrenaline response.
Abstract: Theophylline and caffeine either inhibited or potentiated the noradrenaline constrictor response in an isolated perfused mesenteric artery preparation. The type of response observed was dependent on both the concentration of noradrenaline and the concentration of methylxanthine. Theobromine produced only inhibition of the noradrenaline response.
5 citations
01 Jan 1973
TL;DR: The increased toxicity of caffeine, theophylline, and theobromine in the presence of either pargyline, iproniazid, tranylcypromine, or β–phenylisopropylhydrazine shows that the methyl xanthines are capable of interacting with monoamine oxidase inhibitor.
Abstract: Publisher Summary This chapter discusses the role of brain serotonin in the pharmacologic effects of the methyl xanthines. The methyl xanthines, caffeine, theophylline, and theobromine are the most widely consumed drugs. Studies on their molecular site of action have focused on cyclic–3', 5'–adenosine monophosphate (c–3', 5'–AMP), an intracellular mediator of a number of hormonal effects. In vitro, caffeine or theophylline elevate the c–3', 5'–AMP levels by inhibiting its catabolism by phosphodiesterase. The increased toxicity of caffeine, theophylline, and theobromine in the presence of either pargyline, iproniazid, tranylcypromine, or β–phenylisopropylhydrazine shows that the methyl xanthines are capable of interacting with monoamine oxidase inhibitor. Serotonin has been postulated to participate in temperature regulation, migraine headache, sedation, and sleep. Caffeine is used therapeutically alone or in combination with other drugs to modify all of these.
3 citations