Sodium nonivamide acetate: a non-pungently antinociceptive capsaicin derivative with unusual anti-inflammatory properties.

1. Bradykinin-induced vascular pain in conscious rats, hyperalgesia in the rat hind paw, rat hind paw edema induced by compound 48/80 and carrageenin and dye exudation induced by intraperitoneal injection of 0.7% acetic acid in mice were all inhibited by sodium nonivamide acetate (SNA). 2. Collagen and arachidonic acid-induced rabbit platelet aggregations were inhibited by SNA and capsaicin. In human platelet microsomes, prostaglandin E2 formation in arachidonic acid metabolite was not inhibited by SNA but was inhibited by capsaicin and indomethacin; thromboxane B2 formation and its synthetase activity were inhibited by SNA and capsaicin. 3. In the extracellular recording, SNA could not decrease the action potential amplitude of the vagus nerve. 4. The motor activity of mice induced by caffeine (1.0 mg/kg) was inhibited by SNA and capsaicin.