Onali P, Olianas M C
Department of Neurosciences, University of Cagliari, Italy.
Neurosci Lett. 1989 Jul 17;102(1):91-6. doi: 10.1016/0304-3940(89)90313-3.
In homogenates of rat nucleus accumbens, quinpirole, a dopamine (DA) D2 receptor agonist, inhibited the activation of tyrosine hydroxylase (TH) elicited by either forskolin, an activator of adenylate cyclase, or rolipram, a cyclic nucleotide phosphodiesterase inhibitor. The inhibition produced by 1 microM quinpirole was completely antagonized by the D2 blocker L-sulpiride (2 microM). Quinpirole failed to inhibit the stimulation of TH elicited by dibutyryl cyclic AMP (2 mM), which acts independently of adenylate cyclase. Quinpirole (10 microM) significantly inhibited the stimulation of adenylate cyclase activity elicited by 1 microM forskolin. These results indicate that mesolimbic DA autoreceptors can regulate TH activity by inhibiting a presynaptic adenylate cyclase system.
在大鼠伏隔核匀浆中，多巴胺（DA）D2受体激动剂喹吡罗可抑制由腺苷酸环化酶激活剂福斯可林或环核苷酸磷酸二酯酶抑制剂咯利普兰引发的酪氨酸羟化酶（TH）的激活。1微摩尔喹吡罗产生的抑制作用被D2阻滞剂L-舒必利（2微摩尔）完全拮抗。喹吡罗未能抑制由二丁酰环磷酸腺苷（2毫摩尔）引发的TH刺激，二丁酰环磷酸腺苷的作用独立于腺苷酸环化酶。喹吡罗（10微摩尔）显著抑制由1微摩尔福斯可林引发的腺苷酸环化酶活性的刺激。这些结果表明，中脑边缘DA自身受体可通过抑制突触前腺苷酸环化酶系统来调节TH活性。
