Abnormal activity of polymodal receptors induced by clioquinol (5-chloro-7-iodo-8-hydroxyquinoline).
To know possible involvement of primary afferents in paresthesia of subacute myelo-optico-neuropathy (SMON), influence on polymodal receptor, a type of nociceptor, of its causal agent clioquinol (5-chloro-7-iodo-8-hydroxyquinoline) was tested using in vitro testis-superior spermatic nerve preparations of dogs. Exposure to clioquinol (greater than 1 microM) induced an abnormal bursting activity in polymodal receptors, and thereafter the receptors were sensitized to an algesic stimulus (hypertonic saline) and gained a new sensitivity to cold, while pure mechanoreceptors were not influenced. On the other hand, clioquinol glucuronide (100 microM), a detoxicated form, had no such effects. These results are consistent with several clinical observations of sensory aberrations, suggesting possible involvement of the abnormal activities of polymodal receptors in SMON paresthesia.
D000818:Animals; D007464:Clioquinol / Q000494:pharmacology*; D003080:Cold Temperature; D004285:Dogs; D006912:Hydroxyquinolines / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009619:Nociceptors / Q000187:drug effects*; D010525:Peripheral Nerves / Q000187:drug effects; D013085:Spermatic Cord / Q000294:innervation; D013737:Testis / Q000294:innervation
D006912:Hydroxyquinolines; D007464:Clioquinol