title: Adenosine attenuates the vasoconstrictor response to the cold pressor test in humans.
abstract: The forearm vasoconstrictor response to a standardized cold pressor test (CPT) was studied twice in eight healthy subjects, once during local intraarterial infusion of adenosine and once during infusion of equipotent dosages of the control vasodilator sodium nitroprusside (SNP). During local SNP infusion, the forearm vascular resistance (FVR) decreased from 70 +/- 14 to 30 +/- 7 arbitrary units (AU). Adenosine induced a comparable vasodilator response, with a decrease in FVR from 56 +/- 14 to 28 +/- 6 AU. Subsequent cold exposure induced a mean percentage increase in FVR of 62 +/- 17% during SNP, whereas the increase was only 27 +/- 12% during adenosine infusion (p = 0.014). There were no differences in the calculated cold-induced changes in forearm production of norepinephrine (NE) between the SNP and the adenosine tests. We conclude that adenosine attenuates forearm vasoconstrictor response to the CPT, probably by a postjunctional mechanism of action.
authors.affiliation: Department of Medicine, University Hospital Nijmegen, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Smits
authors.forename: J W
authors.initials: JW
authors.lastname: Lenders
authors.forename: J J
authors.initials: JJ
authors.lastname: Willemsen
authors.forename: J A
authors.initials: JA
authors.lastname: den Arend
authors.forename: T
authors.initials: T
authors.lastname: Thien
mesh_terms: D000241:Adenosine / Q000008:administration & dosage / Q000494:pharmacology*; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D005542:Forearm / Q000098:blood supply*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007261:Infusions, Intra-Arterial; D008297:Male; D009599:Nitroprusside / Q000008:administration & dosage / Q000494:pharmacology; D013564:Sympathetic Nervous System / Q000502:physiology; D014661:Vasoconstriction / Q000187:drug effects*
chemical_list: D009599:Nitroprusside; D000241:Adenosine