Proton magnetic resonance imaging enables non-invasive monitoring of lesion formation in
multiple sclerosis and has an important role in assessing the potential effects of
therapy. T2-weighted and short tau inversion recovery magnetic resonance imaging were used to assess the effect of a neurotrophic
adrenocorticotrophic hormone analogue [H-Met(O(2))-Glu-
His-Phe-D-
Lys-Phe-
OH] on the volume of lesions in the brains of rats suffering from chronic
experimental allergic encephalomyelitis, an animal equivalent of
multiple sclerosis. Lesion volume was monitored during a five-month period. Magnetic resonance imaging indicated that treatment with the
adrenocorticotrophic hormone analogue significantly reduced the lesion volume by 84 and 85% 10 and 20 weeks after lesion induction, respectively. Furthermore,
peptide treatment significantly reduced chronic
experimental allergic encephalomyelitis-related neurological symptoms during the chronic phase of the disease (week 3 until week 20 after lesion induction). Both functional and morphological recovery were considerably advanced by
peptide treatment. Twenty weeks after lesion induction rats with chronic
experimental allergic encephalomyelitis were killed for histological analysis, to correlate magnetic resonance imaging findings with morphological changes. The regions of abnormally high signal intensities on T2-weighted magnetic resonance images coincided with areas of
demyelination and concomitant widespread inflammatory infiltration, oedema formation and enlarged ventricles. The improved neurological status and the 84% reduction in the lesion volume in the cerebrum of rats chronic
experimental allergic encephalomyelitis point to the potential value of trophic
peptides in the development of strategies for limiting the damage caused by central demyelinating lesions in syndromes such as
multiple sclerosis.