Caffeine is a commonly used neurostimulant that also produces cerebral vasoconstriction by antagonizing adenosine receptors. Chronic caffeine use results in an adaptation of the vascular adenosine receptor system presumably to compensate for the vasoconstrictive effects of caffeine. We investigated the effects of caffeine on cerebral blood flow (CBF) in increasing levels of chronic caffeine use...

a simple, sensitive, accurate and precise simultaneous uv spectrophotometric method has been developed for the estimation of carisoprodol, paracetamol and caffeine in tablet dosage form. the absorption maxima of the drugs were found to be 221, 248 and 273 nm for carisoprodol, paracetamol and caffeine respectively, in methanol, using a double beam uv/visible spectrophotometer. carisoprodol, para...

Caffeine is a commonly used stimulant thought to have ergogenic properties. Most studies on the ergogenic effects of caffeine have been conducted in athletes. The purpose of this study was to test the hypothesis that caffeine reduces ratings of perceived exertion and increases liking of physical activity in sedentary adults. Participants completed treadmill walking at 60% to 70% of their maxima...

Caffeine is the most widely consumed psychoactive substance and is a legal stimulant that is readily available to children. Caffeine has occasionally been considered a drug of abuse and the potential for dependence on caffeine has been debated. Presently, due to a paucity of clinical evidence on caffeine dependence or abuse, no such diagnosis is included in the Diagnostic and Statistical Manual...

Caffeine, a purine alkaloid drug, has been recognized as a contaminant of water bodies in various climatic regions, however, these environmental caffeine concentrations are the first to be reported in the tropical Caribbean. The major objective of this study was to develop an improved method to extract caffeine from surface and wastewaters in the warm Caribbean environment and measure caffeine ...

Caffeine is the most frequently ingested neuroactive drug in the world and it is largely used to delay fatigue and improve physical activity. Caffeine can modulate NO synthesis in cells and may influence muscular function by modifying the cellular cycle life-death. There is little data concerning the relationship between caffeine in the heart, NOS expression and apoptosis and no data regarding ...

In patients with Type I diabetes and healthy volunteers, ingestion of modest amounts of caffeine augments the usual symptomatic and counter-regulatory responses to hypoglycaemia. The aim of the present study was to determine whether these are lost with sustained caffeine use, i.e. does tolerance develop? Eleven healthy caffeine consumers underwent two identical hyperinsulinaemic glucose clamp p...

The effect of physiological concentrations of caffeine (purified from Persian tea) on adenosine deaminase (ADA) activity at physiological and pathological concentrations of adenosine (as substrate) in 50 mM Tris-HCl buffer (pH 7.3) at 37°C was investigated, using UV-VIS spectroscopy. ADA exhibited a bi-phasic activity behavior and both phases showed positive cooperativities indicating adenosine...