title: Active and inactive L-prolyl-L-leucyl glycinamide synthetic analogs in rat models of levodopa-treated Parkinson's disease.
abstract: The tripeptide, L-prolyl-L-leucyl-glycinamide (PLG) has been shown to facilitate dopaminergic mechanisms in the brain. In the present study, we evaluated the interaction of PLG and its synthetic analogs with levodopa in two animal models of Parkinson's disease. In one experiment using rats with chronic unilateral lesions of the nigrostriatal dopamine pathway, PLG and Z-PLG potentiated the contraversive rotation elicited by levodopa with carbidopa (L/C). In a second experiment using reserpinized rats, PLG, Z-PLG and cyclo-LG potentiated L/C reversal of hypokinesia. Further studies of the PLG analogs, Z-PLG and cyclo-LG as adjunctive drugs with levodopa in the treatment of parkinsonism are warranted.
authors.forename: T C
authors.initials: TC
authors.lastname: Case
authors.forename: S R
authors.initials: SR
authors.lastname: Snider
authors.forename: V J
authors.initials: VJ
authors.lastname: Hruby
authors.forename: T
authors.initials: T
authors.lastname: Rockway
mesh_terms: D000818:Animals; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D002230:Carbidopa / Q000627:therapeutic use; D004151:Dipeptides / Q000627:therapeutic use; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D007980:Levodopa / Q000627:therapeutic use*; D009075:MSH Release-Inhibiting Hormone / Q000031:analogs & derivatives*; D009043:Motor Activity / Q000187:drug effects; D009479:Neuropeptides; D010300:Parkinson Disease / Q000188:drug therapy*; D010456:Peptides, Cyclic; D051381:Rats; D013329:Structure-Activity Relationship
chemical_list: D000978:Antiparkinson Agents; D004151:Dipeptides; D009479:Neuropeptides; D010456:Peptides, Cyclic; D007980:Levodopa; C021166:cyclo(leucylglycine); D009075:MSH Release-Inhibiting Hormone; D002230:Carbidopa