Enhanced antinociception with repeated microinjections of apomorphine into the periaqueductal gray of male and female rats.
Enhanced antinociception with repeated microinjections of apomorphine into the periaqueductal gray of male and female rats.
复制标题
通过向雄性和雌性大鼠的导水管周围灰质重复显微注射阿扑吗啡来增强抗伤害作用。
DOI：
10.1097/fbp.0000000000000373
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发表时间：
2018
影响因子：
1.6
通讯作者：
Morgan,MichaelM
中科院分区：
文献类型：
--
作者：
Schoo,ShaunaM;Bobeck,ErinN;Morgan,MichaelM
Dopamine neurons in the ventrolateral periaqueductal gray (PAG) have been reported to contribute to antinociception. The objective of this study was to determine how this dopamine-mediated antinociception differs from what is known about morphine-induced antinociception. Microinjection of the dopamine receptor agonist apomorphine into the PAG produced a dose-dependent increase in hot plate latency and a decrease in open field activity that was greater in male than in female rats. The peak antinociceptive effect occurred 5 min after apomorphine administration. Surprisingly, the antinociceptive potency of apomorphine was enhanced following systemic administration of the opioid receptor antagonist naloxone in male, but not in female rats. The antinociceptive potency of microinjecting apomorphine into the ventrolateral PAG in male and female rats was also enhanced following twice-daily injections for 2 days. The characteristics of apomorphine-induced antinociception differ from previous reports of morphine antinociception following PAG microinjections in that morphine antinociception peaks at 15 min, is blocked by naloxone, and is susceptible to tolerance with repeated administration. These results indicate that apomorphine-induced antinociception is distinct from opioid-induced antinociception, and that dopamine receptor agonists may provide a novel approach to pain modulation.
