Caffeine physiological properties

The coffee and cola industries owe their wealth to the physiological properties of the drug caffeine. 

The uterine SR possesses a Ca-ATPase and both ryanodine (RyR) and InsP3 (InsP3R) receptors. All three types of RyRs are found in the uterus (Martin et al 1999). The single-channel properties of the three subtypes of RyR appear to be rather similar but there are reported differences between them in their caffeine sensitivity. There is much current interest in assessing the physiological contribution of the RyR subtypes. All three L1SP3RS have also been reported in the uterus (Martin et al 1999), with no data available on whether changes occur in... 

Because the physiological and pharmacological properties of caffeine represent the cumulative effects of not only the parent compound but also its metabolites, it is quite possible that effects attributed to caffeine per se are in fact mediated by one or more of its metabolites. It must also be noted that most of the knowledge about caffeine s effects has been derived from acute administration to fasted subjects submitted to a period of caffeine abstinence in order to ensure low plasma caffeine concentrations. It is thus difficult to extrapolate the results to the usual pattern of caffeine consumption in which... 

The physiological and pharmacological properties of caffeine cannot be explained by a single biochemical mechanism. Three principal hypotheses have been investigated to explain the diverse actions of caffeine. 

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