Substance P enhances the local activation of NK1R-expressing c-kit+ cardiac progenitor cells in right atrium of ischemia/reperfusion-injured heart

Background Localization of neurokinin 1 receptor (NK 1 R), the endogenous receptor for neuropeptide substance P (SP), has already been described for the right atrium (RA) of the heart. However, the biological role of SP/NK 1 R signal pathways in the RA remains unclear. Sprague-Dawley rats were randomly divided into 4 groups ( n = 22 each); subjected to sham, ischemia/reperfusion-injury (I/R), I/R with 5 nmole/kg SP injection (SP + I/R), and SP +...