MIF-1, a synthetic tripeptide with
MSH-release inhibitory properties, has been reported to improve symptoms of
Parkinson's disease, attenuate
levodopa-related
dyskinesias and diminish the dyskinetic movements of
Tardive dyskinesia. More recently,
MIF-1 has been reported partially to protect against the nigro-striatal
dopamine depleting effects of
MPTP in mice, raising the possibility that it may exert protective effects against the development of
Parkinson's disease. There is evidence to suggest that
MIF-1 increases nigro-striatal dopaminergic activity, but its ability to improve symptoms in patients with
Parkinson's disease,
levodopa-related
dyskinesias and
Tardive dyskinesia cannot be explained solely on the basis of the
drug's effect on striatal dopaminergic neurons.
MIF-1 has been reported to potentiate the melanocyte-lightening effect of
melatonin in rats and its effects in patients with
Parkinson's disease and
Tardive dyskinesia are associated with marked mood elevation. It is, therefore, possible that the effects of
MIF-1 in
movement disorders are associated with increased
melatonin secretion. Thus, hypothalamic MIF may modulate nigro-striatal dopaminergic functions in part via pineal
melatonin. Such an interaction represents a novel mechanism by which hypothalamic
peptides act to modulate the expression of
movement disorders.