Ikumi Arai (1), Takao Shimazoe (1,*), Akiko Yoshimatsu (1), Hirotaka
Inoue (1), Shigenobu Shibata (2) and Shigenori Watanabe (1)
(1) Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kyushu
University 62, Fukuoka 812-8582, Japan
(2) Department of Pharmacology, School of Human Sciences, Waseda University,
Tokorozawa, Saitama 359-1164, Japan
(*) To whom correspondence should be addressed.
Abstract: We examined the influence of ischemia on methamphetamine
(MAP)-induced behavioral sensitization and enhancement of dopamine (DA)
release. After the recovery period of the ischemia operation, rats were
treated with MAP (1 mg/kg, i.p.) once daily for 6 consecutive days. Re-administration
of MAP (0.5 mg/kg, i.p.) potentiated the increase of locomotor activity
after a 3-day withdrawal and the enhancement of DA release from striatal
slices after a 6-day withdrawal. The MAP-induced sensitization was impaired
by 5 min ischemia. On the other hand, the increase of locomotor activity
induced by single MAP (1 mg/kg, i.p.) administration was impaired by 20
min of ischemia. Moreover, in saline-treated rats the increase of DA release
from striatal slices induced by MAP (10 microM) application was also impaired
by 20 min of ischemia. These results indicate that the neuronal plastic
change may be very vulnerable to ischemia in MAP-induced sensitization.
Keywords: Methamphetamine, Ischemia, Sensitization