Nerve growth factor (
NGF) can increase expression of
dopamine 2 receptors (D2R) in GH3 rat
pituitary tumor cells (GH3 cells). As D2R exists in long (D2L) and short (D2S)
isoforms, effects of
NGF on D2R subtypes have not been accurately evaluated. In this study, we compared
mRNA levels of D2R subtypes in GH3 cells treated with or without
NGF with real-time RT-PCR. In addition, we also evaluated the relationship between GH3 cell growth after
bromocriptine treatment and
mRNA levels of D2R subtypes. We found that D2R total, D2L, and D2S
mRNA in GH3 cells were significantly increased after
NGF treatment, compared with the vehicle group. Moreover,
NGF increased the ratio of D2S to D2L. GH3 cell survival rate after
bromocriptine treatment was negatively correlated with D2R total
mRNA, and D2S may be more potent than D2L in inhibiting cell growth. Cell apoptosis rate was highly elevated in GH3 cells treated with
NGF and
bromocriptine, compared with the control group or the group treated with
NGF or
bromocriptine alone. Our data provide preliminary evidence that the effect of
NGF was more prominent on expression of D2S than D2L, in addition, D2S might have a greater impact suppressing GH3 cells growth than D2L.