Sci China B. 1990 Jun; 33(6): 686-93.

Accelerated synthesis and release of angiotensin II in the rat brain during electroacupuncture tolerance.

Wang KW, Han JS.

Department of Physiology, Beijing Medical University, PRC.

Behavioural studies suggested that cerebral angiotensin II (AII) plays an important role in the development of tolerance to electroacupuncture (EA) analgesia. Observations made in this study revealed an increase in AII immunoreactivity (AII-ir) in both CSF and brain as well as an increase in the cerebral content of AI-ir in rats rendered tolerant to EA. The extracts of brain from rats receiving EA for 1h and 3h were subjected to gel filtration and the elution profile was compared with that of normal brain extract. There was a marked right shift of the AII peak from the large molecule precursor to the small molecule AII-ir. The latter peak showed the same retention time in HPLC system as that of AII. The results suggest that the acceleration of the synthesis and release of AII during a long-term EA stimulation might constitute one of the mechanisms for EA tolerance.