The role of substance P of the central nervous system in the pathogenesis of spontaneously hypertensive rats.

In comparing the involvement of substance P (SP) in the central regulation of vasomotor tone in Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR), we found that: the degree of SP-like immunoreactivity (SPLI) in the hypothalamus, rostral ventral surface of the medulla oblongata (RVM) and intermediolateral cell column (IML) of the thoracic spinal cord of SHR rats was significantly higher than in WKY rats; intrathecal injection (ith) of SP receptor antagonist D-Pro2, D-Phe7, D-Trp9-SP (D-SP) caused a decrease of mean blood pressure (MBP) in both SHR and WKY rats. These results indicate that SP might participate in the pathogenesis of hypertension and the regulation of normal blood pressure.