[Relationship between the presynaptic depolarization effect of acupuncture and r-aminobutyric acid, opioid peptide and substance P].
The present study was performed on 22 cats to explore whether r-aminobutyric acid (GABA), endogenous opioid peptide and substance P (SP) were involved in the regulation of presynaptic inhibition in acupuncture analgesia. The size of the antidromic compound C action potentials of the sural nerve evoked by the testing stimulation in spinal cord was measured as an indicator of C-afferent terminal excitability. It was found that the electro-acupuncture (EA) at "Huantiao" (GB30) and "Yang lingquan" (GB34) points induced significant enlargement of the antidromic C-waves, showing the depolarization of presynaptic terminals of primary C-afferents was enhanced. The depolarization effect of EA was significantly reduced by bicuculline, naloxone and the antiserum of SP locally applied to the surface of spinal cord respectively. It is supposed that GABA, endogenous opioid peptide and SP may be involved in the regulation of presynaptic inhibition in acupuncture analgesia.
Li
C
C
Institute of Acupuncture, China Academy of Traditional Chinese Medicine, Beijing.
Zhu
L
L
Li
W
W
Ji
C
C
D000200:Action Potentials; D000818:Animals; D002415:Cats; D015671:Electroacupuncture; D004723:Endorphins / Q000378:metabolism*; D009412:Nerve Fibers / Q000502:physiology; D017729:Presynaptic Terminals / Q000502:physiology*; D013373:Substance P / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D004723:Endorphins; D013373:Substance P; D005680:gamma-Aminobutyric Acid