Acupuncture at ST36 prevents chronic stress-induced increases in neuropeptide Y in rat

Chronic stress, as seen in post-traumatic stress disorder, can exacerbate existing diseases. Electroacupuncture (EA) has been proposed to treat chronic stress, although information on its efficacy or mechanism(s) of action is limited. While many factors contribute to the chronic stress response, the sympathetic peptide, neuropeptide Y (NPY), has been shown to be elevated in chronic stress and is hypothesized to contribute to the physiological stress response. Our objective was to determine if EA at acupuncture point stomach 36 (ST36) is effective in mitigating cold stress-induced increase in NPY in rats. Both pretreatment and concomitant treatment with EA ST36 effectively suppressed peripheral and central NPY after 14 d of cold stress (P < 0.05). The effect was specific, as NPY in Sham-EA rats was not different than observed in stress-only rats. Additionally, the effect of EA ST36 was long-lasting, as NPY levels remained suppressed despite early cessation of EA ST36, while exposure to cold stress was continued. In the paraventricular nucleus (PVN), it was notable that changes in NPY mirrored plasma NPY levels, and that the significant elevation in PVN Y1 receptor observed with stress was also prevented with EA ST36. The findings indicate that EA ST36 is effective in preventing one of the sympathetic pathways stimulated during chronic stress, and thus may be a useful adjunct therapy in stress-related disorders.