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Biomedical subjects

J S Han

Publications and source records attributed to J S Han.

At least 361 records · Page 20Linked to original sources
PubMed1982

Tolerance to electroacupuncture analgesia was reversed by microinjection of 5-hydroxytryptophan into nuclei accumbens in the rabbit.

Electroacupuncture (EA) of the hind limb points of the rabbit for 10 min elicited a significant increase of the latency of aversive responses (ARL) induced by radiant heat stimulation of the snout. This effect of analgesia was found to be gradually diminished when EA was applied repeatedly for 6 hr, implying the development of tolerance. A reversal of EA tolerance was achieved by microinjection of 5-hydroxytryptophan (5-HTP) (the direct precursor of 5-hydroxytryptamine (5-HT)), either intracerebroventricularly (200 micrograms) or into bilateral nuclei accumbens (10 micrograms). Injection of the same amount of 5-HTP into brain structures adjacent to nucleus accumbens, e.g., globus pallidus, corpus callosum, internal capsule, etc., was ineffective. It is concluded that a functional insufficiency of 5-HT in the brain, especially in nucleus accumbens, may constitute one of the mechanisms for the development of EA tolerance.

5-Hydroxytryptophan↗
PubMed1982

The implication of central serotonin in electro-acupuncture tolerance in the rat.

Electro-acupuncture (EA) applied to both legs for 30 min raised the tail flick latency of the rat significantly. This effect of EA analgesia became attenuated and finally disappeared after repeated EA stimulations, which was termed EA tolerance. EA tolerance and its cross tolerance to morphine analgesia were found to be partially reversed by intracerebro-ventricular injection of 5-hydroxytryptophan (5-HTP), the precursor of 5-hydroxytryptamine (5-HT). However, there was no depletion in cerebral 5-HT, nor was there decrease of the number of 5-HT receptors in the brain of the EA tolerant animals. Results obtained from different lines of analysis point to the conclusion that development of tolerance to profoundly released 5-HT during prolonged EA stimulation may constitute one of the mechanisms for EA tolerance.

5-Hydroxytryptophan↗
PubMed1981

Effect of intracerebral microinjection of naloxone on acupuncture- and morphine-analgesia in the rabbit.

Although there are unequivocal evidences indicating the participation of endogenous opiate-like substances in acupuncture analgesia, their exact sites of action remain to be elucidated. From the results of localization studies by injecting minute amount of narcotic antagonist naloxone into discrete brain areas and assessing its effect on acupuncture analgesia in rabbits it is concluded that nuclei accumbens, amygdala, habenula and periaquaductal grey are the strategic sites for endogenous opioids to exert their analgesic effect. These brain areas are also of extreme importance for the realization of morphine analgesia.

Acupuncture Therapy↗
PubMed1980

Central neurotransmitters and acupuncture analgesia.

The role played by central neurotransmitters in acupuncture analgesia was evaluated by correlating neurochemical changes in central nervous system with the acupuncture effect, as well as modification of the acupuncture effects by pharmacological manipulations of central neurotransmitters. The results of experimental studies which were performed mainly on rats and rabbits indicated that central serotonin and endogenous opiate-like substances (OLS) seem to be the most important substrates for mediation of acupuncture analgesia while central catecholamines, especially norepinephrine through alpha receptors, may exert an antagonistic effect. It was also found that prolonged and repeated acupuncture resulted in a gradual decrease of the acupuncture effects. The development of some endogenous anti-opiate substrates (AOS) in central nervous system was tentatively implicated.

Acetylcholine↗