CAPSAZOCAINE - A CAPSAICIN-SENSITIVE FUNCTIONAL ANTAGONIST DISPLAYS AN ARGUMENT ON SENSORY CAPSAICIN RECEPTOR

1. Intravenous infusion of capsazocaine (CAPBZ), a molecular fusion pr oduct of irritant synthetic capsaicin and local analgesic benzocaine, at 100 mu g/kg/min for 15 min inhibited capsaicin (10 mu g/kg, IV)-ind uced spinal release of substance P-like immunoreactivity and vagus ref lex responses in blood pressure and heart rate changes in rats. 2. Int rathecal perfusion of CAPBZ (1.0 nM) also reversed retrograde epigastr ic intraarterial capsaicin (10 mu g/kg)-induced hypotensive spinal ref lex, 3. In isolated guinea pig tissues, CAPBZ (1.0-100.0 mu M) inhibit ed capsaicin (1.0 mu M)-sensitive sensory and functional activities, i ncluding cardiatonic, bronchial, tracheal and ileal contractilities. C APBZ is suggested to be a capsaicin antagonist. (C) 1997 Elsevier Scie nce Inc.