methylxanthine


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Related to methylxanthine: caffeine, aminophylline, Xanthines

methylxanthine

(mĕth″ĭl-zăn′thēn)
A group of naturally occurring agents present in caffeine, theophylline, and theobromine. They act on the central nervous system, stimulate the myocardium, relax smooth muscle, and promote diuresis. A commonly prescribed methylxanthine is theophylline, which is used primarily to treat asthma and chronic obstructive pulmonary disease.

methylxanthine (meth´ilzan´thēn),

n diuretic agent (e.g., aminophylline, caffeine, or theophylline) that serves as a smooth muscle relaxant and cardiac muscle and CNS stimulant. Clinically, it is employed as a bronchodilator.

methylxanthine

methylated derivatives of xanthine, including caffeine, theobromine and theophylline.
References in periodicals archive ?
25) Individuals, indeed, often may react differently to mate than to coffee, but this likely reflects the different mix and amounts of methylxanthines and/or other factors rather than supposed special properties of mateine.
Extraction of methylxanthines from Guarana seeds, mate leaves, and cocoa beans using supercritical carbon dioxide and ethanol.
Methylxanthines and fibrocystic breast disease: a study of correlations.
The effects of methylxanthines on the mobility of stored turkey sperm.
PTX, TPY and TBR are methylxanthine phosphodiesterase inhibitors which reduce super oxide anions responsible for DNA apoptosis when used in a concentration of 3.
Caffeine elimination depends highly on cytochrome P450IA2 isoenzyme-mediated N-demethylation, which leads to a variety of urinary methylxanthine metabolites [154].
Limited attention has been paid to the possible role of metabolites of methylxanthines (caffeine, theophylline, and theobromine) in the pathogenesis of urolithiasis, although their average daily output in urine, depending on dietary intake, is ~500 mg/day (4), which equals the output of UA.
A simplified diagram of the metabolism of methylxanthines in humans is shown in Fig.
The absence of 9-MUA is consistent with the assumption that MUAs in stones are metabolites of methylxanthines originating from plants, which never contain a methyl group at N-9 of the purine ring.
Derivatives of methylxanthines were the dominant purines accompanying UA in stones in this study.
Such calculi comprise as little as 5%-10% of all stones in the US population (23); therefore, the influence of methylxanthines on the occurrence of all kinds of urolithiasis could remain imperceptible.
Methylxanthines stimulate calcium transport and inhibit cyclic nucleotide phosphodiesterases in abalone sperm.