title: Facilitation of morphine withdrawal symptoms and morphine-induced conditioned place preference by a glutamate transporter inhibitor DL-threo-beta-benzyloxyaspartate in rats.
abstract: There is a body of evidence implying the involvement of the central glutamatergic system in morphine dependence. In this study, we examined the effect of intracerebroventricular (i.c.v.) administration of a potent glutamate transporter inhibitor, DL-threo-beta-benzyloxyaspartate (DL-TBOA), on acute morphine-induced antinociception, expression of somatic and negative affective components of morphine withdrawal, and acquisition of morphine-induced conditioned place preference in rats. I.c.v administration of DL-TBOA (10 nmol) to naive rats did not affect the acute antinociceptive effect of morphine. I.c.v. administration of DL-TBOA (10 nmol) to morphine-dependent rats significantly facilitated the expression of naloxone-precipitated somatic signs and conditioned place aversion. DL-TBOA (3 and 10 nmol) significantly facilitated acquisition of morphine-induced conditioned place preference. DL-TBOA itself produced neither conditioned place aversion nor place preference in naive rats. These results suggest that central glutamate transporters play inhibitory roles in the expression of somatic and negative affective components of morphine withdrawal and the reinforcing effect of morphine.
authors.affiliation: Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Sekiya
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Tohru
authors.initials: T
authors.lastname: Ozawa
authors.forename: Masabumi
authors.initials: M
authors.lastname: Minami
authors.forename: Masamichi
authors.initials: M
authors.lastname: Satoh
mesh_terms: D027322:Amino Acid Transport System X-AG / Q000037:antagonists & inhibitors* / Q000502:physiology; D000818:Animals; D001224:Aspartic Acid / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology* / Q000523:psychology
chemical_list: D027322:Amino Acid Transport System X-AG; C120673:benzyloxyaspartate; D001224:Aspartic Acid; D009020:Morphine