Autoradiographic analysis of dopamine D1 receptors in the gerbil brain following transient cerebral ischemia.
1. We studied the postischemic time-course of dopamine D1 receptors in selectively vulnerable areas in the gerbil using receptor autoradiography. 2. [3H]SCH 23390 was used to label dopamine D1 receptors and transient cerebral ischemia was induced for 10 min. 3. [3H]SCH 23390 binding showed no significant alteration in selectively vulnerable areas at an early stage (1-24 hr) of recirculation. Thereafter, [3H]SCH 23390 binding showed a significant reduction in most selectively vulnerable areas 48 hr or 7 days of recirculation. The ventromedial striatum and dentate gyrus which were resistant to ischemia also exhibited a significant reduction in [3H]SCH 23390 binding. 4. Especially, marked reduction was noted in the dorsolateral striatum. However, this reduction in the dorsolateral striatum was not seen early in the recirculation prior to morphological neuronal damage. 5. The result suggests that transient cerebral ischemia can cause a severe reduction in dopamine D1 receptors in most selectively vulnerable areas. Furthermore, they suggest that dopamine D1 transmission is not always responsible for the evolution of ischemic brain damage. 6. These findings are discussed in relation to the mechanism of ischemic brain damage.
Araki
T
T
Department of Neurology, Tohoku University School of Medicine, Sendai, Japan.
Murakami
F
F
Kanai
Y
Y
Kato
H
H
Kogure
K
K
D000818:Animals; D001345:Autoradiography; D001552:Benzazepines / Q000494:pharmacology; D001923:Brain Chemistry; D005849:Gerbillinae; D002546:Ischemic Attack, Transient / Q000378:metabolism*; D008297:Male; D017447:Receptors, Dopamine D1 / Q000032:analysis / Q000378:metabolism*
D001552:Benzazepines; D017447:Receptors, Dopamine D1