L-TRYPTOPHAN ENHANCES ANALGESIC EFFECT OF BACLOFEN / 中国药理学通报

ABSTRACT

Analgesia caused by ip baclofen 6. 4 a.nd 12. 8 mg/kg was examined by the hot plate method, showing no accompanied significant changes in 5-HT and 5-HIAA in mouse brains. After loading of L-tfyptophan, the analgesic effect of baclofen was markedly enhanced in both potency and duration, a.nd was related to increases in 5-HT and 5-HIAA in the brain0 Baclofen analgesia was still seen 3d after p-chloro-pheny 1-alanine treatment which rendered 5-HIAA level down to 39% of control. The enhanced functon of 5-HT system in the brain exerted significant synergic effect' on analgesic effect which, however, may be elicited by activating the GABA receptor.