Effect of acetylcholinesterase inhibition with pyridostigmine on cardiovascular parameters in mice with myocardial infarction

Abstract

The benefit of pyridostigmine (PYR), an acetylcholinesterase inhibitor, on mean arterial pressure (MAP), heart rate (HR) and intrinsic heart rate (IHR) was evaluated in mice (C57Bl/6J) submitted to myocardial infarction (MI). Mice were anesthetized (isoflurane) and telemetry transmitters (DSI) were implanted into the left carotid artery. After 5–7 days of recovery, basal MAP (mmHg) and HR (bpm) were recorded for 48 hours (10s every 10min). Further, basal MAP and HR were recorded continuously followed by methylatropine and propranolol administration. After basal recordings, mice were submitted to sham surgery or left anterior descending (LAD) coronary occlusion and received drinking water with or without PYR (3 mg/kg p.o. for 7 days). Five days after LAD occlusion, or sham surgery, recordings were repeated. Sham surgery did not affect MAP, HR and IHR (n=6). LAD occlusion (n= 3) promoted a MI of 11±1 %, decreased MAP (91±1 vs 106±1 before), increased HR (555±11 vs. 481±18 before) and did not affect the IHR (481±11 vs. 466±7 before). LAD occlusion combined with PYR (n=6) did not show any alteration in MAP (101±6 vs. 100±2 before), HR (489±20 vs. 469±15 before) and IHR (448±41 vs. 453±27 before). The results demonstrate that MI caused a decrease in MAP and an increase in HR combined with no alteration in IHR. In addition, PYR prevented the alterations in MAP and HR caused by MI, and did not change the IHR.