Influence of adriamycin locally injected into infraorbital nerve on substance - P in lateral nucleus caudalis spinalis nervi trigemini in adult rats

Abstract

Objective To observe the influence of adriamycin applied locally to infraorbital nerve on the substance P in the lateral nucleus caudalis spinalis nervi trigemini in adult rats. Methods 0. 5% adriamycin was directly injected into the infraor- bital nerve on one side, and normal saline in the opposite as control. The trigeminal ganglions were observed under electro - micro- scope at 3,7,14,21,28,42 days respectively after local administration of adriamycin and normal saline in both groups. Substance P (SP) like positive immunoreactive granules in the lateral nucleus caudalis spinalis nervi trigemini (CNV) on both sides were examined by immunohistochemical method. Results Degenerated trigeminal ganglion ceils were found in adriamycin treated nerves,while myelinated fibers remained intact. The grey scale value of SP like positive immunoreactive granules in the experi- mental side was markedly less than that on control side (P < 0. 01), while no significant difference was present between the groups in different duration. Conclusion Adriamycin locally administered can produce selective destruction of trigeminal gangli- on cells,and can reduce the levels of SP in regions of CNV. As an important neurotransimitter,anbstance P,its synthesis and re- lease is possibly related to the pathogenesis of trigeminsl neuralgia and plays significant role in its onset. The results suggested that local administration of adriamycin is of promising therapeutic implications, further to lay a relevant theoretical foundation in clini- cal management of trigeminal neuralgia. Key words: Adriamycin; Trigeminal neuralgia; Trigeminal ganglion; Substance P