Effects of citalopram on dopamine D2 receptor expression in the rat brain striatum.

ABSTRACT

Effects of citalopram on dopamine D2 receptor expression in the rat brain striatum were studied. Repeated administration of citalopram increased the amount of dopamine D2 receptors, the level of dopamine D2 receptor mRNA, and the transcription rate of the dopamine D2 receptor gene. Single administration of citalopram also increased the level of dopamine D2 receptor mRNA with a maximum effect in 2-4 h after the treatment, and the transcription rate of the dopamine D2 receptor gene. The administration of 5-hydroxytryptophan (5-HTP) also increased the level of dopamine D2 receptor mRNA. These results suggest that the increase in the dopamine D2 receptor expression induced by citalopram may be owing, at least partially, to the stimulation of the dopamine D2 receptor gene transcription, and that serotonin (5-HT) may mediate the effects of citalopram in the induction of dopamine D2 receptor expression.