Nicotine, but not cotinine, partially protects dopaminergic neurons against MPTP-induced degeneration in mice

In order to analyze the putative neuroprotective role of nicotine and cotin ine in parkinsonian syndrqmes,; these two compounds were administered in ma le C57B16 mice for 4 weeks. On day 8, four injections of 1-methyl-4-phenyl- 1,2,3,6,-tetrahydropyridine (MPTP) were administered. MPTP intoxication ind uced a 50% loss of dopaminergic neurons in the substantia nigra and a 45% r eduction in dopaminergic fibers in the striatum. Administration of cotinine did not affect MPTP toxicity in the nigrostriatal system but chronic nicot ine treatment showed a slight protection (15%) of nigrostriatal dopaminergi c neurons against MPTP. (C) 2001 Elsevier Science B.V. All rights reserved.