Effects of streptomycin on the rat infraorbital nerve.

Introduction: It has been reported that streptomycin can have anti-neuralgic effects. However, the mode of action is unknown. This article was intended to investigate eventual neurolytic effects of streptomycin on peripheral nerves when applied topically.

Material And Method: The rat infraorbital nerve, used as the experimental model, was treated with 0.01 ml of streptomycin sulphate dissolved either in distilled water or in lidocaine via an infraorbital perineural injection. Saline was used in control animals.

Results: Cross-sections of the nerve, a week following treatment with streptomycin, revealed damaged axons with disintegration of both heavily and thinly myelinated fibres. Signs of regeneration were detected from the fourth postoperative week on. In control rats no damage was observed.

Conclusion: Streptomycin can cause peripheral nerve damage when injected perineurally. These morphological changes may be responsible for anti-neuralgic effects of streptomycin.