Abstract:

Objective To develop an experimental autoimmune encephalomyelitis(EAE) model in Lewis rats and observe its pathological characteristics for studying multiple sclerosis.
Methods An EAE model was established by immunizing Lewis rats with both guinea pig spinal cord homogenate in complete Freund’s adjuvant and pertussis toxin. The body weight and behavioral change of rats were monitored each day. Hematoxylin eosin(HE) staining was used to observe the inflammatory infiltration in the brain and spinal cord tissue, luxol fast blue(LFB) staining was utilized to detect demyelination change, and electron microscope was used to observe the ultrastructure of myelin sheath in the spinal cord.
Results Along with the progression of course of disease, EAE model rats showed a significant decrease of body weight; the behavioral abnormality appeared on day 8, the score of nervous function increased gradually, and reached peak on day 12. HE and LFB staining showed the typical pathological changes including perivascular inflammatory cell infiltration and demyelination in white matter. The layers of myelin sheath turned looser in the spinal cord of EAE rats.
Conclusion An EAE model was successfully established in Lewis rats by using whole guinea pigs homogenate.

Key words: multiple sclerosis, experimental autoimmune encephalomyelitis, demyelination, lewis rats