title: Attenuation of MPTP neurotoxicity by rolipram, a specific inhibitor of phosphodiesterase IV.
abstract: Rolipram, a specific inhibitor of the phosphodiesterase IV (PDE IV), has recently been shown to exert neuroprotective effects in an Alzheimer transgenic mouse model and in hypoxic-ischemic damage in the rat brain. It activates the cAMP-dependent protein kinase (PKA)/cAMP regulatory element-binding protein (CREB) signaling pathway and it inhibits inflammation. We tested the neuroprotective effects of the specific PDE IV inhibitor rolipram in C57BL/6 mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We found that rolipram administered at 1.25 mg/kg or 2.5 mg/kg doses significantly attenuated MPTP-induced dopamine depletion in the striatum, and reduced the loss of tyrosine hydroxylase-positive neurons in the substantia nigra. There was a bell-shaped dose effect with greater efficacy at the 1.25 mg/kg dose than 2.5 mg/kg and a higher dose of rolipram, 5 mg/kg, had no protective effect and even increased the mortality of animals when co-administered with MPTP. Rolipram did not interact with MPTP in its absorption into the brain and in its metabolism to 1-methyl-4-phenylpyridinium (MPP(+)). Our data show a neuroprotective effect of the PDE IV specific inhibitor rolipram against dopaminergic neuron degeneration, suggesting that PDE IV inhibitors might be a potential treatment for Parkinson's disease.
authors.affiliation: Department of Neurology and Neuroscience, Weill Medical College of Cornell University, 525 East 68th Street, New York, NY 10021, USA.
authors.forename: Lichuan
authors.initials: L
authors.lastname: Yang
authors.forename: Noel Y
authors.initials: NY
authors.lastname: Calingasan
authors.forename: Beverly J
authors.initials: BJ
authors.lastname: Lorenzo
authors.forename: M Flint
authors.initials: MF
authors.lastname: Beal
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006719:Homovanillic Acid / Q000378:metabolism; D020267:MPTP Poisoning / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010726:Phosphodiesterase Inhibitors / Q000627:therapeutic use*; D020889:Rolipram / Q000627:therapeutic use*
chemical_list: D010726:Phosphodiesterase Inhibitors; D015102:3,4-Dihydroxyphenylacetic Acid; D020889:Rolipram; D004298:Dopamine; D006719:Homovanillic Acid