The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 
 
 

Cardiovascular effects of two xanthines and the relation to adenosine antagonism.

We hypothesize that the hemodynamic effects of xanthine derivatives depend on their ability to antagonize the vasodilating effects of endogenous adenosine. In a randomized, double-blind, and placebo-controlled study of 10 normotensive volunteers caffeine, a xanthine with in vitro adenosine antagonistic properties, increased mean arterial pressure by 5.6 +/- 0.9 mm Hg and lowered heart rate by 5.3 +/- 1.1 beats/min. After administration of enprofylline, a xanthine without adenosine antagonism, forearm vascular resistance decreased by 5.6 +/- 3.4 IU, heart rate increased by 10.6 +/- 2.6 beats/min, and plasma adrenaline, plasma noradrenaline, and renin activity increased by 178 +/- 86%, 14 +/- 8%, and 36 +/- 13%, respectively. Adenosine infusion alone induced a dose-related increase in pulse pressure and heart rate, and it increased plasma adrenaline and noradrenaline by 186 +/- 77% and 132 +/- 55%, respectively. This response to adenosine was reduced by pretreatment with caffeine but not enprofyline. Thus opposite circulatory responses to caffeine and enprofylline occurred, with signs of vasoconstriction and vasodilation, respectively. In addition, caffeine, but not enprofylline, reduced the cardiovascular response to exogenous adenosine.[1]

References

  1. Cardiovascular effects of two xanthines and the relation to adenosine antagonism. Smits, P., Schouten, J., Thien, T. Clin. Pharmacol. Ther. (1989) [Pubmed]
 
WikiGenes - Universities