[Ziwuliuzhu acupuncture modulates Glu/GABA‑Gln metabolic loop abnormalities in insomniac rats]

To investigate the therapeutic effect of Ziwuliuzhu acupuncture in a rat model of insomnia and its regulatory effect on the glutamic acid (Glu)/γ-aminobutyric acid (GABA)-glutamine (Gln) metabolic loop.

Forty male SD rats were randomly assigned to control group, model group, Najia group and Nazi group (n=10). In the latter 3 groups, rat models of insomnia were established by intraperitoneal injections of p-chlorophenylalanine and verified using a sodium pentobarbital-induced sleep test. After modeling, the rats in Najia and Nazi groups received acupuncture for 7 days at specifically chosen sets of acupoints based on the Ziwuliuzhu rationale in traditional Chinese medicine. Pathological changes in the hypothalamic tissue of the rats were examined with HE staining, and the levels of Glu and GABA in the hypothalamus were determined with high-performance liquid chromatography (HPLC)-mass spectrometry (MS)/MS. Immunohistochemistry was used to detect the expressions of GABAA receptors (GABAARs) in the hypothalamus, and the expression levels of glutamate decarboxylase (GAD65/67) and glutamine synthetase (GS) were determined with Western blotting.

Compared with the model group, the rats in Najia and Nazi groups exhibited decreased Glu levels and GABAA receptor expression and increased GABA levels with a decreased Glu/GABA ratio in the hypothalamus. Ziwuliuzhu acupuncture significantly increased the protein expressions of GAD65 and GAD67 and lowered the expression of GS in the hypothalamus in the rat models of insomnia.

Ziwuliuzhu acupuncture produces sedative and hypnotic effects in rat models of insomnia possibly by regulating Glu and GABA-Gln metabolism to restore the excitatory/inhibitory balance between Glu and GABA.