Effect of rolipram on intracellular contents of neurotransmitter in cultured dopaminergic neurons

• Published in: Japanese Journal of Pharmacology Vol. 67; no. suppl.1; p. 101
• Main Authors: Yamashita, Nobuyuki, Miyashiro, Mio, Matsunaga, Keita, Ichimaru, Yasuyuki, Sawa, Aiko
• Format: Journal Article
• Language: English; Japanese
• Published: The Japanese Pharmacological Society 1995
• ISSN: 0021-5198; 1347-3506
• DOI: 10.1016/S0021-5198(19)46368-3

Rolipram is a selective phosphodiesterase IV (PDE IV) inhibitor. and its binding sites are abundant in brain. We examined the effect of rolipram on intracellular contents of dopamine (DA) and its metabolite, dihydroxyphenyl acetate (DOPAC) in primary cultured dopaminergic neurons. Ventral mesencephalic cells of rat embryo (15 day-old) were cultured in medium containing serum for 8～9 days. Then the cells were incubated in medium containing forskolin, an adenylate cyclase activater, and/or rolipram for 60 minutes. The cells were sonicated in perchloric acid, and then cenrifuged. The intracellular contents of DA and DOPAC in supernatant were measured by high performance liquid chromatography (HPLC). Forskolin increased the intracellular contents of DA and DOPAC in a concentration-dependent manner. Rolipram significantly increased the intracellular contents of DA (at 100 nM) and DOPAC (at 10, 100 nM) respectively, in the cells stimulated with forskolin 0.3 μM (suboptimal stimulation). These results show rolipram is able to increase the level of DA in dopaminergic neurons when adenylate cyclase is activated. In dopaminergic neurons, the increased intracellular cAMP probably activates tyrosine-hydroxyrase, rate-limiting enzyme in DA-biosynthesis, via activation of A-kinase.