A MORPHOLOGICAL AND FUNCTIONAL ASSESSMENT OF MYCOBACTERIUM LEPRAE-INDUCED NERVE DAMAGE IN A GUINEA-PIG MODEL OF LEPROUS NEURITIS

Nerve damage, resembling that caused by Mycobacterium leprae in man, w as created by the injection of cobalt-irradiated M. leprae organisms i nto the tibial nerve of guinea-pigs. Assessment of nerve damage was ma de by clinical, electrophysiological and morphometric means at interva ls up to 13 weeks after injection. Quantitative immunohistochemical an alysis of neuropeptide-containing fibres in the skin of the foot was a lso carried out. Significant nerve damage occurred 3 weeks after injec tion of M, leprae organisms. Motor and sensory functional loss peaked at 5 weeks after injection, and there was a significant decrease of pe ptide-immunoreactive nerves in all skin compartments. The nerve damage was self-limiting and functional recovery had occurred by 13 weeks. T he model shows many of the features found in the nerve damage of treat ed leprosy patients.