ABSTRACT
<p><b>OBJECTIVE</b>To explore the changes of substance P in cornu dorsal medullae spinalis effected by activation of astrocytes in rats with pain from chronic prostatitis.</p><p><b>METHODS</b>Sixty SD rats were randomized into three groups: the control group (n=20), the chronic prostatitis pain model group (n=20) and the interference group (n=20). The model was induced by injection of complete Freund adjuvant and 3% carrageenan into the prostate. Propentofylline was given with PE-10 in the spinal cord of the rat models. The activation of astrocytes and the distribution of substance P in the spinal cord were detected with immunofluorescence and the changes of substance P observed by radioimmunoassay.</p><p><b>RESULTS</b>The activation of astrocytes was significantly increased in the models compared with controls, but significantly reduced in interfered group in comparison with the pain model group (P < 0.01), and such was the case with substance P (P <0.01).</p><p><b>CONCLUSION</b>The activation of astrocytes was one important reason for the changes of substance P excreted from cornu dorsal medullae spinalis in the chronic prostatitis rats.</p>