Acute But Not Chronic Caffeine Impairs Functional Responses To Ischaemia-Reperfusion In Rat Isolated Perfused Heart

• Published in: Clinical and experimental pharmacology & physiology Vol. 28; no. 1-2; pp. 19 - 24
• Main Authors: Rose'Meyer, Roselyn B, Headrick, John P, Peart, Jason N, Harrison, Glenn J, Garnham, Bronwyn G, Willis, Roger J
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Blackwell Science Pty 01.01.2001
• Subjects: adenosine; Animals; Arrhythmias, Cardiac - drug therapy; Blood Pressure - drug effects; Blood Pressure - physiology; caffeine; Caffeine - administration & dosage; Caffeine - pharmacology; Central Nervous System Stimulants - administration & dosage; Central Nervous System Stimulants - pharmacology; contraction amplitude; Coronary Vessels - drug effects; heart rate; Heart Rate - drug effects; Heart Rate - physiology; Male; Myocardial Ischemia - drug therapy; Myocardial Reperfusion; rat heart; Rats; Rats, Wistar; Time Factors
• ISSN: 0305-1870; 1440-1681
• DOI: 10.1046/j.1440-1681.2001.03389.x

SUMMARY 1. The effect of acute (50 μmol/L) and chronic (0.06% in drinking water for 14 days) caffeine on the response to ischaemia–reperfusion was studied in Wistar rat isolated perfused hearts. 2. Neither acute nor chronic caffeine modified normoxic heart rate or left ventricular pressures. However, acute caffeine decreased coronary flow by up to 20%, while chronic caffeine consumption increased coronary flow by approximately 15% and abolished the vasoconstrictor effect of acute caffeine (P < 0.05). 3. After 15 min global ischaemia, chronic caffeine treatment did not alter the recovery of left ventricular diastolic pressure (LVDP), end‐diastolic pressure (EDP) or heart rate during reperfusion, but did enhance coronary flow rate (P < 0.05). Acute caffeine inhibited the recovery of LVDP and elevated postischaemic EDP in both caffeine‐naïve and chronic caffeine‐treated groups. Acute caffeine also significantly inhibited coronary reflow in naïve but not chronic caffeine‐treated groups and produced a transient tachycardia during reperfusion in hearts from chronic caffeine‐treated rats. 4. The incidence of arrhythmias was unaltered by chronic caffeine treatment, but was increased by acute caffeine in both naïve and chronic caffeine hearts. 5. In conclusion, chronic caffeine intake alone has no detrimental effects on recovery from ischaemia; however, acute caffeine worsens postischaemic contractile function in hearts from naïve and chronic caffeine‐treated rats.