[The changes of substance P contents in central nervous system of renal hypertensive rats].

The changes of substance P-like immunoreactivity (SPLI) were determined in the central nervous system of renal hypertensive rats (produced by application of a constricting clip on the left renal artery), as compared with those of sham-operated controls. The results showed that the substance SP (SP) contents in the rostral ventrolateral medulla (RVM) and intermediolateral cell column (IML) of the thoracic spinal cord in renal hypertensive rats (RHR) were significantly higher than those in the control group. On the other hand, there was no significant difference of SP content in the hypothalamus (HP) between RHR and control groups. Intrathecal injection of SP antagonist lowered the mean blood pressure in both RHR and control groups. This data suggests that the excess SP contents in RVM and IML may be closely related to the pathogenesis of hypertension.