- 作者: Pao-Luh Tao, Chien-Fang Chen and Eagle Yi-Kung Huang
- 作者服務機構: Division of Mental Health and Addiction Medicine, Institute of Population Health Sciences, National Health Research Institutes, Taiwan, R.O.C.
- 中文摘要: --
- 英文摘要:
BACKGROUND: Co-administration of dextromethorphan (DM) with morphine during
pregnancy and throughout lactation has been found to reduce morphine physical dependence
and tolerance in rat offspring. No evidence was presented, however, for the effect of DM
co-administered with morphine during pregnancy on inflammatory hyperalgesia in
morphine-exposed offspring. Therefore, we attempt to investigate the possible effect of
prenatal morphine exposure on the vulnerability to hyperalgesia and the possible therapeutic
effect of DM in the present study. METHODS: Fifty μl of carrageenan (20 mg/ml) was
injected subcutaneously into the plantar surface of the right hind paw in p18 rats to induce
hyperalgesia. Mean paw withdrawal latency was measured in the plantar test to index the
severity of hyperalgesia. Using Western blotting and RT-PCR, the quantitative analyses of
NMDA receptor NR1 and NR2B subunits were performed in spinal cords from different
groups of animals. RESULTS: In the carrageenan-induced hyperalgesia model, rat offspring
passively exposed to morphine developed a severe hyperalgesia on postnatal day 18 (p18),
which also had a more rapid time course than those in the controls. Co-administration of DM
with morphine in the dams prevented this adverse effect of morphine in the offspring rats.
Western blot and RT-PCR analysis showed that the levels of protein and mRNA of NMDA
receptor NR1 and NR2B subunits were significantly higher in the lumbar spinal cords of rats
(p14) exposed to prenatal morphine; the co-administration of DM could reverse the effect of morphine on NR1 and attenuate the effect on NR2B. CONCLUSIONS: Thus, DM may have
a great potential in the prevention of higher vulnerability to inflammatory thermal
hyperalgesia in the offspring of morphine-addicted mothers.
- 中文關鍵字: --
- 英文關鍵字: --