کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2955363 1577505 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Caffeine Prevents Protection in Two Human Models of Ischemic Preconditioning
کلمات کلیدی
موضوعات مرتبط
علوم پزشکی و سلامت پزشکی و دندانپزشکی کاردیولوژی و پزشکی قلب و عروق
پیش نمایش صفحه اول مقاله
Caffeine Prevents Protection in Two Human Models of Ischemic Preconditioning
چکیده انگلیسی

ObjectivesWe studied whether caffeine impairs protection by ischemic preconditioning (IP) in humans.BackgroundIschemic preconditioning is critically dependent on adenosine receptor stimulation. We hypothesize that the adenosine receptor antagonist caffeine blocks the protective effect of IP.MethodsIn vivo ischemia-reperfusion injury was assessed in the thenar muscle by 99mTc-annexin A5 scintigraphy. Forty-two healthy volunteers performed forearm ischemic exercise. In 24 subjects, this was preceded by a stimulus for IP. In a randomized double-blinded design, the subjects received caffeine (4 mg/kg) or saline intravenously before the experiment. At reperfusion, 99mTc-annexin A5 was administered intravenously. Targeting of annexin was quantified by region-of-interest analysis, and expressed as percentage difference between experimental and contralateral hand. In vitro, we assessed recovery of contractile function of human atrial trabeculae, harvested during heart surgery, as functional end point of ischemia-reperfusion injury. Field-stimulated contraction was quantified at baseline and after simulated ischemia-reperfusion, in a paired approach with and without 5 min of IP, in the presence (n = 13) or absence (n = 17) of caffeine (10 mg/l).ResultsIschemic preconditioning reduced annexin targeting in the absence of caffeine (from 13 ± 3% to 7 ± 1% at 1 h, and from 19 ± 2% to 9 ± 3% at 4 h after reperfusion, p = 0.006), but not after caffeine administration (targeting 11 ± 2% and 16 ± 3% at 1 and 4 h). In vitro, IP improved post-ischemic functional recovery in the control group, but not in the caffeine group (8 ± 3% vs. −8 ± 5%, p = 0.003).ConclusionsCaffeine abolishes IP in 2 human models at a dose equivalent to the drinking of 2 to 4 cups of coffee. (The Effect of Caffeine on Ischemic Preconditioning; http://clinicaltrials.gov/ct/show/NCT00184912?order=1; NCT00184912).

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the American College of Cardiology - Volume 48, Issue 4, 15 August 2006, Pages 700–707
نویسندگان
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