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Cardiovascular effects of two xanthines and the relation to adenosine antagonism.
Clin Pharmacol Ther. 1989 Jun; 45(6):593-9.CP

Abstract

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.

Authors+Show Affiliations

Department of Internal Medicine, University of Nijmegen, The Netherlands.No affiliation info availableNo affiliation info available

Pub Type(s)

Clinical Trial
Journal Article
Randomized Controlled Trial
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

2659234

Citation

Smits, P, et al. "Cardiovascular Effects of Two Xanthines and the Relation to Adenosine Antagonism." Clinical Pharmacology and Therapeutics, vol. 45, no. 6, 1989, pp. 593-9.
Smits P, Schouten J, Thien T. Cardiovascular effects of two xanthines and the relation to adenosine antagonism. Clin Pharmacol Ther. 1989;45(6):593-9.
Smits, P., Schouten, J., & Thien, T. (1989). Cardiovascular effects of two xanthines and the relation to adenosine antagonism. Clinical Pharmacology and Therapeutics, 45(6), 593-9.
Smits P, Schouten J, Thien T. Cardiovascular Effects of Two Xanthines and the Relation to Adenosine Antagonism. Clin Pharmacol Ther. 1989;45(6):593-9. PubMed PMID: 2659234.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Cardiovascular effects of two xanthines and the relation to adenosine antagonism. AU - Smits,P, AU - Schouten,J, AU - Thien,T, PY - 1989/6/1/pubmed PY - 1989/6/1/medline PY - 1989/6/1/entrez SP - 593 EP - 9 JF - Clinical pharmacology and therapeutics JO - Clin Pharmacol Ther VL - 45 IS - 6 N2 - 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. SN - 0009-9236 UR - https://www.unboundmedicine.com/medline/citation/2659234/Cardiovascular_effects_of_two_xanthines_and_the_relation_to_adenosine_antagonism_ L2 - https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0009-9236&date=1989&volume=45&issue=6&spage=593 DB - PRIME DP - Unbound Medicine ER -