OBJECTIVES: The aim of the present study was to compare changes in circulating levels of proopiomelanocortin (POMC) derivates and lactate after remote ischemic preconditioning (IPC) and physical exercise. INTRODUCTION: Remote IPC (rIPC) is cardioprotective following acute myocardial infarction and major cardiac surgery. A blood-borne, transferable factor, released following not only rIPC but also vigorous exercise, mediates protection that is abolished by naloxone suggesting involvement of an opioid-receptor-dependent pathway. DESIGN: Eight healthy volunteers underwent rIPC by four cycles of 5-min inflation of a pneumatic tourniquet to 200 mmHg interrupted by 5 min of deflation. Subsequently, circulating plasma levels of POMC derivates, cortisol, and lactate were measured. After 3 days, the volunteers completed a vigorous exercise program, after which the same compounds were measured. RESULTS: While rIPC was not associated with any significant increase in circulating POMC derivates or lactate, exercise induced significant elevation of both compared with baseline. CONCLUSIONS: We were not able to demonstrate a detectable increase in circulating POMC derivates by a standard rIPC stimulus, suggesting that rIPC effect is not mediated by local or detectable central release of these derivates.
OBJECTIVES: The aim of the present study was to compare changes in circulating levels of proopiomelanocortin (POMC) derivates and lactate after remote ischemic preconditioning (IPC) and physical exercise. INTRODUCTION: Remote IPC (rIPC) is cardioprotective following acute myocardial infarction and major cardiac surgery. A blood-borne, transferable factor, released following not only rIPC but also vigorous exercise, mediates protection that is abolished by naloxone suggesting involvement of an opioid-receptor-dependent pathway. DESIGN: Eight healthy volunteers underwent rIPC by four cycles of 5-min inflation of a pneumatic tourniquet to 200 mmHg interrupted by 5 min of deflation. Subsequently, circulating plasma levels of POMC derivates, cortisol, and lactate were measured. After 3 days, the volunteers completed a vigorous exercise program, after which the same compounds were measured. RESULTS: While rIPC was not associated with any significant increase in circulating POMC derivates or lactate, exercise induced significant elevation of both compared with baseline. CONCLUSIONS: We were not able to demonstrate a detectable increase in circulating POMC derivates by a standard rIPC stimulus, suggesting that rIPC effect is not mediated by local or detectable central release of these derivates.