Partial protection from the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) by Pro-Leu-Gly-NH2(PLG; MIF-1).

The administration of MPTP to man and monkey has been shown to cause a neurotoxic effect on the nigrostriatal dopamine system. MPTP was injected in C57-BL black mice, 36 mg per kg for 7 days, which resulted in permanent reduction of dopamine and serotonin levels in the striatum. In the mice pretreated with PLG, although the striatal dopamine level was also reduced, mean dopamine and serotonin levels were significantly higher than in mice given MPTP alone. It is concluded that PLG could protect at least partially the neurotoxic effect of MPTP.