Effects of saikosaponin A on cocaine self-administration in rats.
We have previously demonstrated that saikosaponin A (SSA) attenuated morphine self-administration behavior. In the present study, we evaluated the effects of SSA on cocaine-maintained responding using self-administration procedure. Rats self-administered cocaine (0.25mg/kg per infusion) under a fixed ratio 1 schedule of reinforcement during daily 3-h session. Once stable basal responses were obtained, rats were pretreated with each doses of SSA (1.0, 2.5, 5.0mg/kg) or its vehicle (5% Tween-80) by an intraperitoneal injection 30min before the start of self-administration testing. Additionally, different groups of rats received either the selective GABAB antagonist SCH 50911 or the GABAA antagonist bicuculline before systemic administration of SSA at dose of 2.5mg/kg. Results showed that SSA significantly reduced cocaine self-administration without affecting food consumption. SSA inhibition of cocaine reinforced-responding was blocked by SCH 50911, but not bicuculline. Results suggest that SSA may attenuate cocaine-reinforced behavior through activation of GABAB receptors.
Center for Safety Pharmacology, Korea Institute of Toxicology, Daejeon 305-343, Republic of Korea.
Seong Shoon
SS
Yoon
Joung-Wook
JW
Seo
Song Hee
SH
Ann
Hee Young
HY
Kim
Hey Soo
HS
Kim
Hea-Young
HY
Cho
Jaesuk
J
Yun
Eun Yong
EY
Chung
Jin Suk
JS
Koo
Chae Ha
CH
Yang
D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D003042:Cocaine / Q000008:administration & dosage*; D058787:GABA-A Receptor Antagonists / Q000494:pharmacology; D058788:GABA-B Receptor Antagonists / Q000494:pharmacology; D008297:Male; D009025:Morpholines / Q000494:pharmacology; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012054:Reinforcement, Psychology; D012503:Saponins / Q000494:pharmacology*; D012646:Self Administration
C095804:(+)-(S)-5,5-dimethylmorpholinyl-2-acetic acid; D058787:GABA-A Receptor Antagonists; D058788:GABA-B Receptor Antagonists; D009025:Morpholines; D012503:Saponins; D009828:Oleanolic Acid; D003042:Cocaine; C025759:saikosaponin D; D001640:Bicuculline
Cocaine; GABA; Reinforcement; Saikosaponin A; Self-administration