[Effects of noradrenaline and dopamine in preoptic area on acupuncture analgesia]

Previous work has shown that activation of catecholamine in the preoptic area is to the disadvantage of acupuncture analgesia. In this work microinjection and push-pull perfusion as well as HPLC-ECD were used to observe the effect of noradrenaline and dopamine in this area on acupuncture analgesia. The results indicated that microinjection of noradrenaline (0.5 microgram/unilateral) into the preoptic area could attenuate acupuncture analgesia, while dopamine (2 micrograms/unilateral) had no effect on acupuncture analgesia. During acupuncture analgesia, the contents of noradrenaline and MHPG in the perfusate from the preoptic area were markedly decreased, and that of dopamine, however, was not changed significantly. The above results suggest that activating noradrenaline, but not dopamine, exerts antagonistic effect on acupuncture analgesia.