The role of parasympathetic mechanisms in the infarct-limiting effect of SGLT2 inhibitor ertugliflozin

IntroductionBased on data that outcome in patients with acute myocardial infarction is predicted by final infarct size (IS), reducing IS is of paramount importance. Recent experimental studies have demonstrated a strong infarct-sparing effect of SGLT2 inhibitors - a class of drugs which have proved to be safe and beneficial in patients with heart failure. Repurposing SGLT2 inhibitors for the benefit of patients presenting with acute myocardial infarction should be preceded by investigation of the underlying mechanisms of this infarct limitation. Experimental and clinical data indicate a potential role for autonomic modulation in these mechanisms, specifically sympatho-inhibition. The aim of this study was to investigate the role of the parasympathetic mechanism in the infarct-limiting effect of SGLT2 inhibition. MethodsFortyeight Sprague Dawley male rats were fed with a standard diet containing either the SGLT2 inhibitor ertugliflozin or vehicle, for 5-7 days. Myocardial ischaemia/reperfusion injury was initiated by a 40-min occlusion of the left anterior descending coronary artery followed by a 2hr period of reperfusion under isoflurane anaesthesia. Bilateral cervical vagotomy was performed 10min prior to myocardial ischaemia. Alternatively, muscarinic receptors were blocked systemically with the non-selective blocker atropine sulphate (2 mg/kg bolus, then 1 mg/kg/h) or the M3-selective blocker 4-DAMP (2 mg/kg bolus). ResultsPre-treatment with ertugliflozin reduced IS in comparison with the vehicle-treated controls (p<0.001). Bilateral vagotomy, atropine sulphate and 4-DAMP all abolished this infarct-limiting effect (IS 35{+/-}10%, 44{+/-}8%, and 35{+/-}4% respectively; P<0.01 vs. Ertu for vagotomy, P<0.001 vs. Ertu for both atropine sulphate and 4-DAMP). ConclusionThese results suggest that the Infarct-limiting effect of the SGLT2 inhibitor ertugliflozin, may be mediated via activation of the vagus nerve and M3-cholinoreceptors.