Relevance of anatomical site to activate remote ischemic preconditioning

DONATO M; GRECO C; PAEZ DT; GELPI RJ

Buenos Aires

Congreso; LXII Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2017

Introduction: Remote ischemic preconditioning (rIPC) reduces myocardial infarct size in different animal species, however, in humans the results are contradictory, probably because it has not been considered the anatomical site of stimulation as a variable that could influence the results.Objective: The aim was evaluate the effects of rIPC on infarct size, considering the optimal anatomical site (arm or thigh) to achieve the myocardial protection. A second objective was to describe some of the pathways involved in the rIPC protection.Methods: Isolated rat hearts were subjected to 30 min of global ischemia followed by 60 min of reperfusion (I/R). In additional groups, a rIPC protocol of 3 cycles of I/R were performed. This protocol was applied to the right and left femoral artery and in the right and left axillary arteries. We studied the involvement of a vagal neural pathway by performing a bilateral cervical vagotomy prior to the rIPC protocol. The humoral pathway was evaluated by administering DPCPX (adenosine A1 receptor blocker). Infarct size was measured using triphenyltetrazolium chloride staining.Results: rIPC performed in the left and right femoral artery significantly decreased infarct size (35,6±1,2 and 30,08±5,2 %, p< 0,05 vs I/R) and this effect was abolished by bilateral vagotomy. In the same way, rIPC performed in the left axillary artery significantly decreased infarct size (27±4,4 %, P< 0,05 vs I/R). This effect was not abolished by bilateral vagotomy. As we mentioned, in order to evaluate the humoral pathway, we administered DPCPX, which completely abolished the beneficial effect of rIPC. Interestingly, rIPC performed in the right axillary artery has not effects on I/R injury.Conclusions: rIPc performed on hind limb reduces infarct size by a parasympathetic vagal pathway. However, in the left arm, rIPC induced protection by activation of adenosine A1 receptors; suggesting the participation of an humoral pathway.