Capsaicin-induced cardioprotection is driven by its hypothermic effect (1154.1)

Objective. We hypothesized that cardioprotective properties of topical capsaicin (CAP) application are related to its hypothermic effect. Methods. Anesthetized rats received CAP cream or vehicle (VCL) applied 15-30 minutes before a 30-minute coronary artery occlusion followed by 2-hour reperfusion. At the end of the protocol, hearts were excised and the area at risk (AR), area of necrosis (AN) and infarct size (AN/AR) were measured. In additional set of animals, hearts were excised at the end of CAP/VCL application, and used for Western Blot assay of p-Akt and p-Erk1/2. Results. CAP cream produced a rapid decrease in pre-occlusion core temperature, ranging from 0.22 to 1.78°C, with a median reduction of 0.97°C. In a CAP subgroup with a temperature decrease of > 0.97°C, AN/AR was decreased by 31% (from 56±4% in the VCL group to 38±4% in the CAP group, p<0.05). In the CAP subgroup with temperature decrease < 0.97°C no difference in the infarct size was observed. CAP induced an increase in p-Akt and p-Erk1/2...