慢性キノホルム中毒犬の病理所見

Chronic poisoning with iodoxyquinoline in dogs

　SMONの病因としてキノホルム製剤が疑われ，それを裏づける動物実験が急がれている。われわれはイヌに同剤を慢性経口投与しSMONとほぼ同一の臨床病理所見を観察し^1〜3），その後Autoradiographyでキノホルムの神経系への分布を確認し^4），またイヌ以外にサル^5），ネコでも同様な中毒症状を認めているが，今回は7頭の慢性中毒イヌの病理所見の総括を試みる。

　Recently, Iodoxyquinoline is suspected to be a causal factor of subacute myelo-optico-neuropathy (SMON) in Japan. We administered this drug to dogs orally for a long period and succeeded in eliciting chronic symptoms such as ataxia and motor paralysis in the hind legs, closely resembling those of "SMON" in man.

　Pathologically, the most characteristic changes of 7 autopsied dogs are various degrees of symmetrical degeneration of nerve fibers in the distal regions of the spinal long tracts, especially in the Goll's tract in the upper cervical segments.