![]() |
|
|
SP Sivam
Department of Pharmacology & Toxicology, Northwest Center for Medical Education, Indiana University School of Medicine, Gary.
The influence of the acute (single dose) or subchronic (one dose daily for 4 days) administration of cocaine to Sprague-Dawley rats on striatal enkephalin (Met5-enkephalin) and striatonigral tachykinin (substance P) and dynorphin [dynorphin A (1-8), DYN] levels was investigated. The peptide levels were determined by radioimmunoassay. The concentrations of the striatal levels of dopamine (DA), 5- hydroxytryptamine and their acid metabolites were determined by high- performance liquid chromatography with electrochemical detection. An acute administration of cocaine (20 or 30 mg/kg i.p.) did not affect the peptide levels in the striatum or in the substantia nigra. A regimen of subchronic administration of cocaine (20 mg/kg/day for 4 days) increased the striatonigral DYN levels, without altering the levels of Met5-enkephalin or substance P. The increase in DYN levels were persistent for at least 4 days after the last dose of the subchronic administration of cocaine. The DYN levels returned to control values by 12 days after the last dose. The DA levels in the striatum were increased 30 min after a single dose of cocaine. None of the other treatments elicited any changes in DA or 5-hydroxytryptamine or their metabolites. The subchronic cocaine administration to dopaminergic denervated rats with 6-hydroxydopamine failed to evoke any increase in DYN levels in the striatum or substantia nigra. The concurrent administration of the D1 DA antagonist, SCH-23390, or the D2 DA antagonist, spiperone, to the subchronic regimen of cocaine also blocked the cocaine-induced increase in DYN levels. These results indicate that cocaine selectively enhances the synthesis or decreases the release of DYN in the striatonigral neurons.(ABSTRACT TRUNCATED AT 250 WORDS)
This article has been cited by other articles:
![]() |
G. Gerra, A. Fantoma, and A. Zaimovic Naltrexone and buprenorphine combination in the treatment of opioid dependence J Psychopharmacol, November 1, 2006; 20(6): 806 - 814. [Abstract] [PDF] |
||||
![]() |
M. J. Kreek, G. Bart, C. Lilly, K. S. Laforge, and D. A. Nielsen Pharmacogenetics and Human Molecular Genetics of Opiate and Cocaine Addictions and Their Treatments Pharmacol. Rev., March 1, 2005; 57(1): 1 - 26. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. L. Walsh, B. Geter-Douglas, E. C. Strain, and G. E. Bigelow Enadoline and Butorphanol: Evaluation of kappa -Agonists on Cocaine Pharmacodynamics and Cocaine Self-Administration in Humans J. Pharmacol. Exp. Ther., October 1, 2001; 299(1): 147 - 158. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. C. Dalman and K. L. O'Malley kappa -Opioid Tolerance and Dependence in Cultures of Dopaminergic Midbrain Neurons J. Neurosci., July 15, 1999; 19(14): 5750 - 5757. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. van Ree, M. A. F. M. Gerrits, and L. J. M. J. Vanderschuren Opioids, Reward and Addiction: An Encounter of Biology, Psychology, and Medicine Pharmacol. Rev., June 1, 1999; 51(2): 341 - 396. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Kreek, J. Schluger, L. Borg, M. Gunduz, and A. Ho Dynorphin A1-13 Causes Elevation of Serum Levels of Prolactin Through an Opioid Receptor Mechanism in Humans: Gender Differences and Implications for Modulation of Dopaminergic Tone in the Treatment of Addictions J. Pharmacol. Exp. Ther., January 1, 1999; 288(1): 260 - 269. [Abstract] [Full Text] |
||||
![]() |
J. K. Staley, R. B. Rothman, K. C. Rice, J. Partilla, and D. C. Mash kappa 2 Opioid Receptors in Limbic Areas of the Human Brain Are Upregulated by Cocaine in Fatal Overdose Victims J. Neurosci., November 1, 1997; 17(21): 8225 - 8233. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Q. Wang and J. F. McGinty The Full D1 Dopamine Receptor Agonist SKF-82958 Induces Neuropeptide mRNA in the Normosensitive Striatum of Rats: Regulation of D1/D2 Interactions by Muscarinic Receptors J. Pharmacol. Exp. Ther., May 1, 1997; 281(2): 972 - 982. [Abstract] [Full Text] |
||||
![]() |
L. Chai, W. S. Choi, and O. K. Ronnekleiv Maternal Cocaine Treatment Alters Dynorphin and Enkephalin mRNA Expression in Brains of Fetal Rhesus Macaques J. Neurosci., February 1, 1997; 17(3): 1112 - 1121. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Moratalla, M. Xu, S. Tonegawa, and A. M. Graybiel Cellular responses to psychomotor stimulant and neuroleptic drugs are abnormal in mice lacking the D1 dopamine receptor PNAS, December 10, 1996; 93(25): 14928 - 14933. [Abstract] [Full Text] [PDF] |
||||